Mental Health in Europe After COVID-19: A Systematic Review of Depression, Anxiety, and Stress Among Adult Primary Health Care Users

Abstract

The COVID-19 pandemic has had a profound impact on mental health globally, especially among users of primary health care (PHC) services. This systematic review aims to synthesize the current evidence on the prevalence and associated factors of depression, anxiety, and stress among adult PHC users in Europe during the post-pandemic period. The review followed PRISMA 2020 guidelines and was registered in PROSPERO (CRD420251033455). We searched Web of Science, PubMed, b-on, and Scopus up to April 2025. Eligible studies included peer-reviewed, quantitative observational studies conducted in Europe from 2022 onward, provided they addressed the post-pandemic context and assessed depression, anxiety, and/or stress using validated tools. Two reviewers independently screened the studies and performed data extraction. The risk of bias was assessed using the ROBINS-I tool. A narrative synthesis of the findings was subsequently conducted. A total of 11 studies involving 8958 participants were included in this analysis. Most studies were cross-sectional and employed tools such as the DASS-21, PHQ-9, and HADS. The prevalence of depressive symptoms reached up to 63%, and anxiety affected over 40% of participants in several studies. Vulnerable groups included women, individuals with chronic illnesses, those unemployed, and persons living alone or facing financial hardship. The risk of bias was moderate to serious in most studies. The evidence highlights significant post-pandemic psychological distress, conceptualized as symptoms of depression, anxiety, and stress measured through validated psychometric instruments, in PHC settings, with underdiagnosis remaining a key issue. Limitations include heterogeneity in assessment tools and designs, as well as reliance on self-report measures. Results underscore the need for routine mental health screening and integrated care in PHC. This review received no specific funding.

1. Introduction

Mental health has emerged as a pressing global public health priority, particularly in the aftermath of the COVID-19 pandemic, which was declared a public health emergency of international concern on 30 January 2020 [1]. An expanding body of evidence has documented the pandemic’s negative impact on mental health indicators. A global systematic review estimated prevalence rates of 28% for depression, 26.9% for anxiety, 36.5% for stress, and a broader psychological distress rate of 50% during the early phase of the pandemic (January–July 2020), underscoring the widespread emotional toll across diverse populations and sociocultural contexts [2].

Mental health is a fundamental component of overall health and well-being, influencing an individual’s capacity to manage stress, build relationships, maintain productivity, and contribute to their community. The World Health Organisation defines mental health not merely as the absence of illness, but as a state of psychological and emotional well-being that enables people to realize their potential and cope with the normal stresses of life [3]. Poor mental health has been consistently linked to a range of negative outcomes, including reduced life expectancy, increased risk of physical illnesses (such as cardiovascular disease), and higher health care utilization. In the context of public health, mental health disorders represent a major burden of disease, contributing significantly to disability-adjusted life years (DALYs) globally. Within primary health care (PHC), addressing mental health is critical, as these settings often serve as the first and sometimes only point of contact for individuals experiencing psychological distress. Strengthening mental health services within PHC is therefore essential for achieving equitable, accessible, and integrated health care systems [4].

This deterioration has proven especially significant among vulnerable populations, such as individuals with chronic illnesses, young adults, and women [5], as well as those with a prior diagnosis of affective or anxiety disorders, whose symptoms were exacerbated during the pandemic [6].

In this context, PHC settings are uniquely positioned to play a key role in the early identification of psychological distress and the implementation of preventive and interventional strategies owing to their accessibility and foundational place within the health system [7,8,9].

Among the validated psychometric instruments used to assess emotional distress, the Depression, Anxiety and Stress Scale-21 items (DASS-21) has been widely employed in both clinical and population-based studies [10,11]. This self-report instrument was designed to measure the three domains independently and has demonstrated robust internal consistency and empirical validity across diverse cultural and clinical settings [12,13], supporting its application within PHC contexts.

In addition to the DASS-21, other instruments have been used to assess the psychological impact of the pandemic. The Hospital Anxiety and Depression Scale (HADS) has been employed in individuals previously infected with SARS-CoV-2 [14]; the Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7) have been applied to individuals with pre-existing mental health conditions [15]; and the Perceived Stress Scale (PSS) has been used to assess perceived stress levels in hospitalized patients [16].

Against this background, the present systematic review aims to synthesize the available scientific evidence on the prevalence of symptoms of depression, anxiety, and stress among adult users of Primary Health Care services in Europe during the post-COVID-19 period, with a particular focus on studies employing the DASS-21 as an assessment tool, given its wide adoption in PHC settings, its robust psychometric properties across diverse populations, and its unique capacity to simultaneously assess symptoms of depression, anxiety, and stress within a single validated instrument. The pandemic has had a profound and lasting impact on global mental health, with growing evidence of increased emotional distress across various populations. Primary health care settings, as the first point of contact for most individuals within health systems, are uniquely positioned to detect and manage early signs of psychological suffering.

Given the rising demand for mental health support and the evolving challenges in the post-pandemic period, it is crucial to understand how depression, anxiety, and stress have manifested in primary care populations. Furthermore, identifying the factors associated with these conditions, such as sociodemographic characteristics, pre-existing health conditions, socioeconomic vulnerabilities, and the ongoing effects of pandemic-related disruptions, can inform the development of targeted interventions and resource allocation.

By synthesizing the existing literature, this review provides a comprehensive overview of the prevalence and associated factors of depression, anxiety, and stress symptoms among primary care users after COVID-19, supporting clinicians, researchers, and policymakers in improving mental health strategies in community-based settings. Furthermore, it aims to identify the sociodemographic, clinical, and psychosocial factors associated with these symptoms, informing the development of more effective, context-sensitive mental health strategies within community-based care. In this review, the term ‘After-COVID-19’ refers to the period following the acute phase of the pandemic, characterized by the lifting of restrictive public health measures and a transition to long-term management of its psychological and social consequences. It is essential to note that this review focuses specifically on adults attending primary health care services in Europe, rather than the general population. This scope highlights the distinct role of PHC in identifying and addressing mental health issues, enabling the development of targeted, service-based strategies.

2. Methods

This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines [17]. The complete PRISMA checklist is provided in Supplementary Materials. The review protocol has been registered on PROSPERO (registration number CRD420251033455) and is publicly accessible. The methodology follows Cochrane recommendations for assessing evidence from randomized controlled trials, ensuring a rigorous and transparent process for evaluating confidence in effect estimates.

2.1. Research Question

The review question was structured using the PCC framework (Population, Concept, Context), which is commonly applied in integrative reviews: Population (P): Adult users of primary health care services; Concept (C): Psychological distress, namely depression, anxiety, and stress; Context (C): Primary health care settings, including family health units, community clinics, and general practice environments.

(a)

RQ1: What are the main findings in the literature regarding the prevalence and associated factors of depression, anxiety, and stress among users of health care services in Europe?

This question aims to guide the identification, synthesis, and analysis of existing evidence on emotional suffering in primary care populations. This will contribute to developing more effective, person-centred mental health strategies within these services.

2.2. Literature Search

To address the research objectives of this integrative review, a comprehensive literature search was performed to identify relevant studies on the prevalence and associated factors of depression, anxiety, and stress among users of primary health care services. The search was conducted across four major databases: b-on (https://www.b-on.pt/), PubMed (https://pubmed.ncbi.nlm.nih.gov/), Web of Science (https://webofknowledge.com/), and Scopus (https://www.scopus.com/), all accessed on 9 April 2025. These databases were chosen for their extensive coverage of high-quality research in medicine, public health, mental health, and primary care.

The search strategy combined controlled vocabulary (MeSH terms) and free-text keywords linked by Boolean operators. Key terms included “depression,” “anxiety,” “stress,” “primary health care,” “family medicine,” “general practice,” and “psychological distress,” along with synonyms and related expressions to maximize retrieval and ensure broad topic coverage.

An example of the search string used in PubMed was: ((“primary health care” OR “family practice” OR “general practice” OR “primary care”) AND (“depression” OR “anxiety” OR “stress, psychological” OR “psychological distress” OR “mental distress” OR “emotional distress” OR “distress”) AND (“COVID-19” OR “post-pandemic” OR “after COVID-19” OR “COVID-19 aftermath”)).

This strategy was adapted for each database’s specific syntax and search capabilities. The search was limited to peer-reviewed articles without restrictions on language or publication date to ensure a comprehensive evidence base. Additionally, reference lists of included articles were screened to identify further relevant studies not captured in the initial search.

This method aimed to provide a thorough and inclusive selection of studies examining psychological symptoms in primary care populations.

2.2.1. Inclusion Criteria

Studies included were (1) studies involving adult users (≥18 years old) of health care services; (2) studies focused on the general population attending primary care, regardless of specific clinical conditions; (3) studies reporting on the prevalence and/or associated factors of depression, anxiety, and/or stress; (4) use of standardized and validated psychological assessment tools (e.g., DASS-21, HADS, PHQ-9, GAD-7, GHQ); (5) studies conducted during the post-acute phase of the COVID-19 pandemic (typically from 2022 onward), provided that they explicitly examined mental health outcomes in the context of the pandemic’s aftermath or post-pandemic recovery; (6) quantitative observational studies, including cross-sectional, cohort, or case–control designs; (7) peer-reviewed journal articles; (8) studies published in any language; (9) full-text availability of the study for data extraction and quality assessment; (10) studies conducted in Europe.

2.2.2. Exclusion Criteria

Studies excluded were (1) studies with only health care professionals, hospitalized patients, children or adolescents (<18 years old), or specialized mental health services users; (2) studies conducted in settings other than health care; (3) studies that did not report data on depression, anxiety, or stress, either as individual domains or as a global construct, as primary or secondary outcomes; (4) articles that only addressed general well-being or quality of life without specifically assessing psychological distress; (5) studies focusing solely on interventions (e.g., clinical trials), without reporting on prevalence or associated factors; (6) studies conducted before the COVID-19 pandemic or with no reference to the pandemic’s context or impact; (7) qualitative-only studies, literature reviews, systematic reviews, meta-analyses, editorials, opinion papers, theses, dissertations, conference abstracts, or study protocols; (8) articles not published in peer-reviewed scientific journals; (9) articles with no full text available for review; (10) studies conducted in other continents besides Europe.

2.3. Types of Outcomes Measured

In this review, psychological distress is conceptualized as a multidimensional construct encompassing symptoms of depression, anxiety, and stress. These domains reflect common emotional responses to prolonged stressors such as the COVID-19 pandemic and have been widely studied as indicators of mental health burden in both clinical and community settings. For operationalization, psychological distress was assessed using validated self-report instruments, including the Depression, Anxiety, and Stress Scale (DASS-21), Patient Health Questionnaire (PHQ-9 and GAD-7), and Hospital Anxiety and Depression Scale (HADS), among others. These tools were selected based on their established reliability and validity in diverse populations, and they formed the primary basis for evaluating the prevalence and severity of emotional distress across included studies.

The primary outcomes considered in this review were related to psychological distress, including either its individual components (depression, anxiety, and stress) or distress as a unidimensional construct, specifically focusing on the following:

• Prevalence rate
  • The proportion of primary health care users presenting symptoms of depression, anxiety, and/or stress, as reported in each study.
  • These prevalence rates were typically categorized by severity levels (e.g., mild, moderate, severe) when applicable.
• Associated Factors
  • Sociodemographic variables (e.g., age, gender, education, employment status).
  • Clinical characteristics (e.g., presence of chronic illnesses, prior mental health diagnoses).
  • Psychosocial factors (e.g., social support, financial hardship, COVID-19 exposure or impact).
  • Behavioural or lifestyle variables (e.g., physical activity, substance use).
• Measurement Tools: Outcomes were evaluated using validated psychometric instruments, such as:
  • Depression, Anxiety and Stress Scale (DASS-21).
  • Hospital Anxiety and Depression Scale (HADS).
  • Patient Health Questionnaire (PHQ-9, GAD-7).
  • General Health Questionnaire (GHQ).
  • Other contextually adapted or validated scales.

Studies were included as long as they reported at least one of the outcomes described above, either as a primary or secondary objective.

2.4. Screening and Eligibility Assessment

The studies were selected according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA 2020) guidelines. All identified records were imported into reference management software (Rayyan) to facilitate screening and remove duplicates.

The study selection process was carried out in two phases:

• Title and Abstract Screening: Two authors independently assessed the titles and abstracts of all retrieved articles, using predefined inclusion and exclusion criteria. Studies that did not meet the criteria were excluded at this stage.
• Full-Text Review: The same reviewers retrieved and independently examined the full texts of potentially eligible studies. Disagreements were resolved through discussion or consultation with a third reviewer when necessary.

A PRISMA flow diagram was used to document the number of records identified, screened, excluded, and included at each stage of the selection process (Figure 1).

2.5. Data Extraction

A data extraction table was developed (SDG). The extracted data included the author(s), year of publication, and country; study design and setting; sample characteristics (e.g., size, age, gender distribution); measurement tools used for depression, anxiety, and stress, or global psychological distress; reported prevalence rates of depression, anxiety, and stress; associated factors identified (sociodemographic, clinical, psychosocial, etc.); and main findings and conclusions. One author (SDG) abstracted the information above, which was double-checked by a second author (FC).

Any discrepancies in data extraction were resolved by consensus. If needed, study authors were contacted for clarification or additional information. No conversions of summary statistics or imputation of missing data were required.

2.6. Risk of Bias

The risk of bias for each study was assessed using the Cochrane Collaboration’s ROBINS-I tool [18,19]. One author (SDG) conducted the initial assessment, which was then independently reviewed by a second author (FC). Disagreements were resolved through discussion. The ROBINS-I tool evaluates five key domains: the randomization process, deviations from intended interventions, missing outcome data, measurement of outcomes, and selection of reported results. Publication bias was examined using funnel plots. Based on the Cochrane criteria, each study was categorized as having a low, moderate, or high risk of bias.

2.7. Study Selection

Search results were exported in .ris format and imported into the Rayyan web tool for systematic reviews [20]. The initial search across the selected databases yielded 1262 articles. All references were also added to a PubMed collection before being imported into Rayyan for title and abstract screening. Duplicate records and those automatically flagged as ineligible were removed, resulting in a pool of 980 unique articles.

Titles and abstracts were then screened to identify potentially relevant studies. Articles unrelated to the research question were excluded, narrowing the selection to 718 articles. Full-text versions of these articles were retrieved using institutional subscriptions and interlibrary loan services when needed. However, three articles could not be obtained due to inaccessible full texts.

The entire selection process was managed using reference management software and is documented in a PRISMA flow diagram (Figure 1), which outlines the number of articles identified, screened, and included at each stage [17]. After applying the inclusion and exclusion criteria, 11 studies were selected for final analysis (

Table 1. Systematic review articles (n = 11).

Study No. Reference Year of Publication Country	Study Design and Setting	Sample Characteristics	Measurement Tools Used	Results of Assessment Tools	Associated Factors Identified	Main Findings and Conclusions
1 [21] 2025 Greece	-Cross-sectional study -Primary Health Care Centres in Western Greece	-212 participants -Mean age: 50.36 years (SD 6.20) -Age range: 40–60 years -Females: 125 (59.4%)	-PHQ-9 -FAST	-PHQ-9: 63.2% had depressive symptoms: -28.3% mild depression -18.4% moderate depression -16.5% severe depression -FAST: Low prevalence of alcohol problems; no significant association with depression	-Marital status (divorced, unmarried, widowed had higher depression). -History of hospitalization. -Presence of chronic physical illness. -Professional status (unemployed and retired showed higher depression). - Presence of children (those without children had higher depression). -Income and educational level showed trends but were less significant	There is a significant underdiagnosis of depression in primary health care during the post-COVID-19 era. Depression was prevalent among middle-aged adults (40–60 years), independent of gender and alcohol consumption. Important demographic and clinical variables influence depression risk. Findings emphasize the need for routine mental health screening in primary care using tools like PHQ-9, especially considering factors like family status, employment, and physical health
2 [22] 2024 Switzerland	-Cross-sectional study. -Conducted in primary care settings (five general practices in the Canton of Vaud) -Data collected at three time points: ·t1: 0–7 days post-consultation t2: 4–8 weeks post-consultation t3: 4–6 months post-consultation	-50 patients -Female: 33 (66%) -Mean age: 47 years (IQR: 36–55)	-HADS -CSF -PCFS -PC-VAS -Study-specific questions regarding symptoms and reasons for consulting the post-COVID outpatient clinic	-Quantitative data indicated that most patients (96%) felt cared for throughout their consultations. -Qualitative interviews highlighted the medical staff’s attentiveness and the time dedicated to consultations, which made patients feel that their complaints were taken seriously and that they received appropriate information	-High emotional burden and fatigue early post-COVID; improvement associated with follow-up care and multidisciplinary support; long wait times noted as a concern	The outpatient clinic effectively addressed patients’ emotional and physical health over time, with most feeling well cared for. Interprofessional support was crucial, and fatigue and restrictions improved significantly by t3
3 [23] 2024 Greece	-Cross-sectional study conducted over two months -Location: Two primary health care sites in the rural region of Farsala, Central Greece -Conducted after the lifting of all COVID-19 restrictive measures	-129 women -27.9% classified as older adults -13.2% reported having a chronic physical disease	-DASS-21	-DASS-21 (Depression): 17.1% of participants reported clinically relevant depressive symptoms. -DASS-21 (Anxiety): Over 40% of participants reported clinically relevant anxiety symptoms. -Symptoms of anxiety and depression were found to be interrelated. -Anxiety and depression symptoms were found to be interrelated	-Older Age: Associated with higher levels of anxiety and depression. -Primary Education: Linked to increased symptoms. -Living Alone: Significantly associated with anxiety (OR 123.5; 95% CI: 7.3–2098.8) and depression (OR 3.5; 95% CI: 1.3–9.8). -Unemployment: Associated with higher anxiety (OR 0.157; 95% CI: 0.06–0.41) and depression (OR 0.08; 95% CI: 0.01–0.62). -Chronic Physical Disease: Strongly linked to anxiety (OR 33.8; 95% CI: 4.3–264.7) and depression (OR 37.2; 95% CI: 10–138.1)	-A significant proportion of community-dwelling women in rural Greece exhibited symptoms of anxiety and depression in the post-COVID-19 era. -Certain sociodemographic factors, such as age, education level, living status, employment status, and chronic disease history, were associated with increased symptoms. -The study emphasizes the importance of screening for depression and anxiety symptoms in women attending rural primary care settings. -Using valid and reliable self-report instruments, such as the DASS-21, can aid in early identification and intervention
4 [24] 2024 Poland	-Longitudinal cohort study assessing psychological outcomes in adults diagnosed with mild COVID-19. -Participants completed online self-report questionnaires at two time points: baseline (T1) and approximately four months later (T2)	-341 adults with confirmed mild COVID-19. -Female: 204 (59.8%) -Mean age: 42.89 (SD 13.89)	-PHQ-ADS -PC-PTSD-5 -Scale of Psychosocial Experience Related to COVID-19: Measured COVID-related stigma and social support. -Self-designed questionnaires: Evaluated the severity of COVID-related medical and neurocognitive symptoms	-Exploratory factor analysis identified five clusters of COVID-19 symptoms: flu-like, respiratory, cold, neurological, and neurocognitive. -Hierarchical logistic regression revealed that neurocognitive symptoms at T1 (e.g., impairments in smell and taste, information processing, memory, thinking, and verbal communication) were significant predictors of prolonged PTSD-like symptoms at T2. - Other symptom clusters (flu-like, respiratory, cold, neurological) did not significantly predict PTSD-like symptoms	-Neurocognitive symptoms during acute COVID-19: Strongly associated with prolonged PTSD-like symptoms. -Emotional symptoms during illness: The Presence of anxiety and depression at T1 contributed to PTSD-like symptoms at T2. -COVID-related stigma: Experiences of social stigma due to infection were linked to increased risk of prolonged PTSD-like symptoms. -Subjective perceptions of neurocognitive deficits: Individuals’ perceptions of their cognitive impairments played a role in the persistence of PTSD-like symptoms	The study concluded that among adults with mild COVID-19, neurocognitive symptoms during the acute phase are significant predictors of prolonged PTSD-like symptoms. Emotional distress and experiences of stigma further exacerbate this risk. The findings underscore the importance of comprehensive neuropsychological assessments and interventions for individuals recovering from COVID-19, even in cases of mild illness. Enhancing access to neuropsychological services is crucial for addressing the mental health needs of this population
5 [25] 2024 Sweden	-Cross-sectional cohort study -Primary care settings	-260 participants -Female: 146 (56.2%)	-GDS-20 -HADS -PSS-10	-Participants reporting mental health impacts due to the COVID-19 pandemic exhibited significantly higher levels of anxiety (p < 0.001), depression (p < 0.001), and stress (p = 0.026) compared to those not reporting such impacts	-Impaired social life -Changes in physical activity - Strained family relationships -Higher levels of anxiety -Being female	The study concluded that anxiety, family situation, social life, and changes in physical activity were the main factors influencing self-perceived mental health among older adults during the COVID-19 pandemic. The findings suggest the need for further investigation into the long-term effects of social restrictions on the mental health of the older population
6 [26] 2024 Switzerland	-Longitudinal cohort study	-5624 adults -Mean age: 51.5 (SD 13.2) -Female: 3456 (57.2%)	-GAD-2 -PHQ-2 -Loneliness Scale	-Depressive and Anxiety Symptoms: Declined during the pandemic wave (Feb–May 2021) and remained lower at follow-ups in 2022 and 2023 compared to the start of the wave. - Loneliness: Also declined over time, with the greatest decrease during the pandemic wave	-Higher-Risk Groups: Socioeconomically disadvantaged individuals, those with chronic conditions, and those living alone exhibited poorer mental health throughout the study period. - Demographics: Women and younger individuals showed faster improvements in mental health during the pandemic wave. - Loneliness: Trajectories of loneliness were closely associated with mental health trajectories throughout the study period	While mental health indicators improved relatively soon after the easing of COVID-19 restrictions, disparities persisted among higher-risk groups. The study underscores the need for continued mental health support for vulnerable populations beyond the pandemic period
7 [27] 2023 United Kingdom	-Cross-sectional survey	-306 adults -Female: 246 (81.2%) -Mean age: 41 years (IQR 28–53)	-CAS -WSAS -EQ-5D-3L -PHQ-9 -GAD-7 -OCI-R -SHAI -SAPAS	-Social Functioning: 52.3% exhibited severe social or occupational dysfunction (WSAS score >20). -Quality of Life: 93.4% reported anxiety or depression; 10.4% rated their health state as worse than death (EQ-5D-3L index <0). -Protective Behaviours: High engagement in protective behaviours, including constant handwashing and avoiding leaving home	-Depressive Symptoms: Strongly correlated with functional impairment (β = 0.45; p < 0.001) and poor quality of life (r = -0.48; p < 0.001). -Obsessive-Compulsive Symptoms: Associated with increased functional impairment (β = 0.13; p < 0.001). -Health Anxiety and Personality Disorder Traits: Linked to poorer quality of life. -Living Alone: Associated with worse social functioning and quality of life. -At-Risk Ethnic Group: Predictive of severe social impairment. -Having a Loved One Hospitalized by COVID-19: Associated with increased functional impairment	Severe COVID-19-related anxiety is associated with significant social and occupational dysfunction, diminished quality of life, and heightened engagement in protective behaviours. Comorbid mental health conditions, such as depression and obsessive-compulsive symptoms, exacerbate these outcomes. The study underscores the need for targeted mental health interventions for individuals experiencing severe COVID-19 anxiety
8 [28] 2023 Germany	-Cross-sectional survey conducted between August and December 2022 across 13 general practices encompassing both urban and rural regions	-795 adults with at least one chronic physical illness (bronchial asthma, COPD, diabetes type 1 or 2, coronary artery disease, or breast cancer)	-5C Scale -PHQ-9 -OASIS -LSNS -PRA -PAM-13	-Depression (PHQ-9): Higher depressive symptoms were significantly associated with lower confidence in COVID-19 vaccines (p = 0.010) and greater perceived constraints to vaccination (p = 0.041). -Anxiety (OASIS): No significant association with vaccination readiness for either COVID-19 or influenza vaccines. -Influenza Vaccination Readiness: No significant associations found with either depression or anxiety levels	-Depression: Negatively impacted confidence and increased perceived barriers to COVID-19 vaccination. - Anxiety: No significant influence on vaccination readiness. - Other Factors: Older age, male gender, and higher education levels were associated with increased vaccination readiness. A strong doctor-patient relationship has a positive influence on vaccination attitudes	Mental health, particularly depressive symptoms, plays a significant role in vaccination readiness among chronically ill patients, specifically concerning COVID-19 vaccines. Addressing mental health issues and strengthening the doctor-patient relationship are crucial strategies to enhance vaccination uptake in this population
9 [29] 2023 Germany	-Prospective observational survey study. -Primary care and community setting.	-60 patients -Female: 36 (60%) -Mean age: 45.4 (SD 14.9)	-GAD-7	-Persistent symptoms reported months after infection. -Depression and anxiety scores were significantly elevated in individuals with lingering symptoms	-Number and intensity of lingering physical symptoms were strongly associated with increased anxiety and depressive symptoms. -No significant associations with age or sex were reported	Lingering physical symptoms in non-hospitalized COVID-19 patients were strongly associated with higher levels of depression and anxiety. Mental health assessment and follow-up in primary care are essential for this group
10 [30] 2023 Spain	Multi-method study combining quantitative and qualitative approaches to assess psychological health among older adults during and after the first COVID-19 lockdown	-111 older adults. -Mean age: 71 years (SD 5 years). -Female: 84 (76%)	-GDS -Cantril Ladder of Life -PGIC -Open-ended questions: Explored personal experiences and perceived changes in depressive symptoms and well-being during quarantine	-Depressive Symptoms: 63% reported mild symptoms; 2% reported major depressive symptoms. -Changes During Lockdown: 47.7% reported changes in depressive symptoms; 37% felt better during lockdown, while 11% reported worsening symptoms post-lockdown. -Well-being: 60% reported a decline in well-being during quarantine	-Psychological Discomfort: Mood deflection, fear and worries, and boredom and inactivity were common themes. -Social Issues: Inability to go out and missing family members contributed to psychological distress	The study highlighted that a significant proportion of older adults experienced worsening depressive symptoms and decreased well-being during and after COVID-19 lockdowns. Psychological discomfort and social isolation were key contributing factors. The findings underscore the importance of evaluating mental health in primary care settings and providing appropriate referrals for older adults affected by pandemic-related restrictions
11 [31] 2023 Austria, Croatia, Georgia, Greece, Portugal	-Longitudinal mixed-methods study with baseline assessment in summer/autumn 2020 (T1) and follow-up 12 months later (T2)	-1070 adults from the general population -Mean age: 42.9 (SD 13.5) -Female: 796 (74.4%)	-ADNM -PC-PTSD-5 -PHQ-2 -WHO-5	-ADNM-8: Significant decrease in Greece (p = 0.007); increase in Georgia (p = 0.035); stable in other countries. -Depressive Symptoms (PHQ-2): Significant decrease in Greece (p = 0.001); slight decrease in Croatia (p = 0.032); stable elsewhere. -Well-Being (WHO-5): No significant change across countries. -PC-PTSD-5: Slight decrease in total sample (p = 0.057)	-Country-Specific Differences: Variations in mental health outcomes across countries. -Time point Variations: Changes in themes such as work/finances (T1) and vaccination issues (T2). -Individual Characteristics: Personal experiences and circumstances influenced psychological responses	Psychological responses to the COVID-19 pandemic varied over time and across countries, influenced by contextual factors and individual circumstances. Resource-oriented interventions focusing on psychological flexibility may promote resilience and mental health during global crises

CAS: Coronavirus Anxiety Scale; CSF: Chalder Fatigue Scale; DASS-21: Depression, Anxiety, Stress Scale-21; EQ-5D-3L: Quality of life; FAST: Fast Alcohol Screening Test; GAD-7: Generalized Anxiety Disorder 7-item; GDS-20: Geriatric Depression Scale; HADS: Hospital Anxiety and Depression Scale; IQR: Interquartile Range; LSNS: Lubben Social Network Scale; OASIS: Overall Anxiety Severity and Impairment Scale; OCI-R: Obsessive-Compulsive Inventory-Revised; PAM: Patient Activation Measure; PAS: Panic and Agoraphobia Scale; PCFS: Post COVID-19 Functional Status Scale; PC-PTSD-5: Primary Care Post-Traumatic Stress Disorder Screen for DSM-5; PC-VAS: post-COVID Visual Analogue Scale; PGIC: Patient Global Impression of Change; PHQ-ADS: Patient Health Questionnaire Anxiety-Depression Scale; PHQ: Patient Health Questionnaire; PRA: Patient-Doctor Relationship Questionnaire; PSS-10: Perceived Stress Scale; SAPAS: Standardized Assessment of Personality—Abbreviated Scale; SD: Standard deviation; SHAI: Short Health Anxiety Inventory; WSAS: Work and Social Adjustment Scale.

).

3. Results

3.1. Study Characteristics

The studies included in this review span nine investigations conducted between 2022 and 2025 across multiple countries (Greece, Switzerland, Poland, Sweden, the United Kingdom, and Germany). Six studies adopted a cross-sectional design [21,22,23,25,27,28]. In contrast, two employed longitudinal cohort designs [24,26], one was a prospective observational study [29], another a longitudinal multi-method study combining a quantitative approach [30], and one was a longitudinal mixed-method study [31]. Data collection primarily occurred in primary care settings or general community environments, often after COVID-19 restrictions had lifted (Table 1).

The total sample across studies included 8958 participants, with individual study sizes ranging from 50 [22] to 5624 participants [26]. Participants were predominantly middle-aged adults, with mean ages ranging from 41 [27] to 71 years [30]. Gender distribution across studies showed a higher proportion of females, typically between 56.2% [25] and 100% [23].

A variety of validated measurement tools were employed to assess psychological outcomes, including the PHQ-9 [21,27,28], HADS [22,25], DASS-21 [23], GDS [25,30], GAD-7 [27,29], PHQ-2 [26,31], and other specific scales targeting anxiety, depression, stress, loneliness, social functioning, and post-COVID symptoms (e.g., FAST, CAS, WSAS, EQ-5D-3L, OASIS). These diverse instruments enabled a comprehensive evaluation of mental health symptoms and their associated social and physical impacts.

The primary outcomes assessed included prevalence rates of depression and anxiety, persistence of post-COVID psychological symptoms, quality of life, functional impairment, and vaccination attitudes. Depression prevalence was notable across settings, with rates ranging from 17.1% [23] to 63.2% [21], while anxiety symptoms were also frequent, affecting more than 40% of participants in some studies [23,25,27].

Several associated factors for worsened psychological outcomes were identified across the studies, such as sociodemographic factors, such as unemployment, living alone, lower education levels, female gender, and older age, were consistently linked to higher depression and anxiety scores [21,23,25,27]. Additionally, clinical history factors such as the presence of chronic physical illnesses and a history of hospitalization were significant predictors of mental health symptoms [21,23,28]. Pandemic-related experiences were also present, like COVID-related stigma [24], impaired social life [25], and lingering physical symptoms [29], which were strongly associated with psychological distress.

Intervention or follow-up effects were reported in longitudinal studies. For instance, in Switzerland [26], depressive and anxiety symptoms declined over time, though persistent vulnerabilities remained among socioeconomically disadvantaged and chronically ill groups. Similarly, follow-up care in outpatient settings was associated with emotional recovery among post-COVID patients [22].

Mental health underdiagnosis was emphasized, particularly in primary care settings [21], where routine screenings using tools such as the PHQ-9 were recommended. Other studies highlighted the impact of emotional symptoms during the acute COVID-19 phase on long-term PTSD-like symptoms [24], reinforcing the need for early psychological assessment post-infection.

While most studies relied on self-reported questionnaires, the consistency in findings across diverse settings strengthens the evidence for significant mental health impacts following the COVID-19 pandemic. Importantly, several studies pointed to the necessity of targeted interventions focusing on vulnerable groups, the incorporation of mental health screenings into routine care, and attention to long-term psychosocial needs.

Overall, these characteristics reflect the enduring burden of psychological symptoms in the post-pandemic era and underline the importance of sustained mental health support in primary and community care settings.

3.2. Risk of Bias

The ROBINS-I tool, which evaluates seven key domains, was used to assess the risk of bias across 11 included studies. The overall risk of bias varied, with moderate to serious concerns predominating in several domains (Figure 2).

Most studies (Studies 1–5) [21,22,23,24,25] presented a serious risk of bias in at least one domain, especially in relation to bias due to confounding (D1) and participant selection (D2). These weaknesses significantly contributed to a serious overall risk of bias in these studies. Study 5 [25] also showed serious risk in multiple domains, including missing data (D5) and measurement of outcomes (D6).

In contrast, Studies 6 to 11 [26,27,28,29,30,31] generally showed a moderate overall risk, with most domains classified as low risk. However, moderate bias was commonly observed in domains such as confounding (D1) and classification of interventions (D3). Study 8 and Study 10 were notable exceptions in this group, with a serious risk related to participant selection (D2), which impacted their overall rating [28,30].

Measurement of outcomes (D6) and selection of the reported results (D7) were consistently rated as low risk in most studies, suggesting that outcome assessment and reporting were generally robust across the included research.

These findings highlight methodological limitations in the observational studies included, particularly regarding the control of confounders and participant recruitment methods, which should be considered when interpreting the results.

4. Discussion

The findings of this review highlight a significant and persistent burden of depression, anxiety, and stress among adults attending primary health care services in Europe during the post-COVID-19 period. Across diverse settings and populations, emotional distress emerged as a prevalent issue, with certain sociodemographic and clinical groups exhibiting elevated vulnerability. Women, individuals living alone, the unemployed, those with chronic physical illnesses, and older adults consistently showed higher levels of psychological symptoms. These patterns suggest that while the acute phase of the pandemic may have passed, its psychological consequences remain deeply embedded in population health and continue to impact everyday functioning and well-being [32].

Primary health care settings are uniquely positioned to identify and respond to early signs of psychological distress due to their accessibility and long-term relationships with patients [33]. Despite this, many individuals experiencing symptoms of depression or anxiety remain undiagnosed or untreated. The findings reinforce the need for systematic mental health screening in primary care, particularly using brief, validated tools like the DASS-21 or PHQ-9, which can facilitate timely identification and intervention. Embedding mental health assessments into routine care could enable earlier support and potentially prevent the escalation of psychological symptoms into more severe or chronic conditions [34].

A recurring theme across the studies was the interconnectedness of mental health symptoms with broader social and economic factors. Experiences of isolation, reduced social interaction, financial hardship, and lifestyle disruptions were commonly linked to emotional distress. This reinforces the idea that mental health cannot be addressed in isolation from its social determinants [35]. Consequently, effective interventions should adopt a holistic approach, considering clinical treatment, social support, community engagement, and economic assistance [36,37,38].

Another essential dimension uncovered in the review is the psychological impact of post-COVID physical symptoms and long-term complications. Lingering fatigue, neurocognitive impairments, and other somatic complaints were associated with increased psychological burden, suggesting a complex interplay between physical health and mental well-being. These findings underscore the importance of integrated care models that address both physical and psychological aspects of recovery, especially for patients experiencing long COVID or related syndromes [39].

The results also suggest a shift in mental health needs, requiring health systems to adapt to the long-term psychological aftermath of the pandemic [32]. While the initial health response focused on infection control and acute care, there is a growing demand for accessible, community-based mental health services. As the first point of contact for many individuals, primary care professionals must be equipped with the knowledge, tools, and support systems necessary to meet this demand effectively.

In summary, the review reveals that depression, anxiety, and stress remain widespread in the post-pandemic era, with specific groups facing disproportionate challenges. The role of primary care is critical in addressing this growing mental health burden, but broader health policies, resource allocation, and community-level interventions must support it. Addressing these issues holistically and proactively will promote population well-being and build resilience against future public health crises.

4.1. Limitations

This review presents several limitations that should be acknowledged when interpreting the findings. First, the heterogeneity of assessment tools used across studies, such as DASS-21, PHQ-9, and HADS, may have introduced inconsistencies in symptom measurement and hindered direct comparison of prevalence rates. Most studies relied on self-reported questionnaires, which are inherently prone to recall bias, social desirability bias, and potential underreporting of psychological symptoms. Furthermore, the predominance of cross-sectional designs limits the ability to establish causal relationships or assess the progression of symptoms over time. Geographically, while the review focused on Europe, there was an uneven distribution of studies, with several countries underrepresented, which may affect the generalizability of the findings across the continent. Additionally, excluding grey literature and studies without accessible full texts may have led to the omission of relevant data, and language barriers could have further influenced study selection.

Furthermore, the findings of this review are limited to studies conducted in primary health care settings. Research conducted in general population samples—particularly large-scale epidemiological surveys—was excluded from this analysis. Therefore, the results are not generalizable to the broader European population. This constraint should be considered when interpreting prevalence rates and associated factors of psychological distress reported herein.

4.2. Future Research

Future research should prioritize longitudinal designs to track the evolution of depression, anxiety, and stress symptoms in primary care populations over time, especially in the post-pandemic context. Intervention-focused studies also need to assess the effectiveness of mental health screening tools and integrated support strategies within primary health care settings. Expanding research efforts to include a more diverse range of European countries, particularly underrepresented regions, will enhance the representativeness of findings. Studies should also focus more deeply on high-risk and vulnerable subgroups, such as individuals with chronic illnesses, socioeconomically disadvantaged populations, and those experiencing social isolation. Incorporating mixed-methods approaches could provide a richer understanding of personal experiences and the contextual factors that influence psychological distress. Lastly, exploring the role of neurocognitive symptoms and pandemic-related stigma as long-term predictors of mental health outcomes may uncover critical pathways for targeted prevention and care.

5. Conclusions

This systematic review provided a global overview and prevalence of mental health problems, specifically depression, anxiety, and stress, among adult users of primary health care services in Europe following the COVID-19 pandemic. While these findings reflect trends observed in PHC populations, they do not represent the general population, as studies included in this review were limited to individuals attending primary health care services.

The impact appeared greater among women, individuals living alone, the unemployed, those with chronic physical illnesses, and older adults—groups frequently encountered in PHC settings. More studies are needed to assess the long-term effects of the COVID-19 pandemic on mental health in both clinical and general population settings.

More studies are needed on the long-term effects of the COVID-19 pandemic on the mental health status of populations globally. Considering the high burden of mental health problems during the COVID-19 pandemic, as demonstrated in various studies, it is important to improve tracking and prevention systems, rapid multidisciplinary management, and additional research on the social and economic burden of the pandemic.