A Comparative Analysis of Mental Health Outcomes in Heterosexual and Sexual Minority University Students

Abstract

University students from diverse sexual orientations encounter specific mental health challenges due to academic demands, minority stress, and societal stigma; however, research focusing on these issues is still scarce in Southeast Asia. This research aimed to examine the mental health outcomes of heterosexual and sexuality-diverse students in Thailand, concentrating on both negative aspects—such as depression, anxiety, and perceived stress—and positive aspects—like resilience, inner strength, and perceived social support. A cross-sectional survey was performed with 442 university students aged between 20 and 30, employing validated self-report instruments. Statistical methods, including t-tests and multiple regression analyses, were used to evaluate differences and relationships between sexual orientation and mental health outcomes while controlling for confounding variables. The findings revealed that sexuality-diverse students showed notably higher levels of depression (B = 0.115, p < 0.05) and lower perceived social support (B = −0.10, p < 0.05) when compared to their heterosexual counterparts. Nevertheless, there were no significant differences found in anxiety, perceived stress, resilience, or inner strength. Perceived social support proved to be a crucial protective factor, with greater levels linked to reduced depression, anxiety, and perceived stress (p < 0.01). These results underscore the necessity for inclusive university policies, specific mental health interventions, and peer and family support initiatives to enhance the well-being of sexuality-diverse students in Thailand.

1. Introduction

University students are at a critical stage of life, facing various mental health challenges such as anxiety, depression, and perceived stress due to academic pressures, social challenges, and the transition to adulthood. These difficulties have often been heightened for sexuality-diverse students, such as LGBTQ+ individuals, who have experienced additional stressors like discrimination and social exclusion. Research has shown that the number of sexual minority students has surpassed 10 million worldwide, accounting for over 10% of the total student population [1]. Despite these figures, many higher education institutions continue to provide inadequate support for sexuality-diverse students [2].

The number of people identifying as LGBTQ+ has increased significantly among younger generations. In the United States, research has indicated that Generation Z (born 1997–2002) have the highest proportion of LGBTQ+ individuals at 15.9% compared to 9.1% of millennials, 3.8% of Generation X, 2% of baby boomers, and 1.3% of traditionalists [3].

A study in the US revealed that LGBTQ racial/ethnic minorities have statistically significantly higher odds than whites in reporting discrimination based on their LGBTQ identity when applying for jobs, trying to vote or participate in politics, and interacting with the legal system [4]. In many Asian societies, sexuality-diverse individuals continue to face discrimination, social isolation, school violence, and exclusion, all of which negatively impact their mental health and well-being. Reports have suggested that 30% of university students experience stress, 22% struggle with anxiety, and 14% suffer from depression, all of which adversely affect academic performance [5].

Thailand is widely recognized for its acceptance of gender diversity, a perspective deeply rooted in the country’s cultural, historical, and religious traditions. Theravāda Buddhism, the predominant religion, does not explicitly condemn LGBTQ+ identities. Its emphasis on karma, where past actions shape life circumstances, encourages a more tolerant and accepting view of diverse identities. Beyond the concept of karma, Thai Buddhist values, such as loving-kindness (mettā) and compassion (karuṇā), help foster inclusivity and empathy [6]. These values underscore the conviction that all beings are entitled to dignity and acceptance, regardless of their gender or sexual identity.

A recent Nida poll indicates that a significant majority of Thais view LGBTQ+ individuals positively as friends, colleagues, and family members, with acceptance levels rising since 2018 and 2019. Among 1310 respondents nationwide, over 90% supported LGBTQ+ inclusion in social and family contexts. Additionally, 79.62% backed the Civil Partnership Bill for same-sex marriage, and 63.59% agreed that LGBTQ+ individuals should be able to change their gender titles before their names. The survey highlights growing societal acceptance, although legal and bureaucratic challenges still persist [7].

In a study of LGBTQIA+ rights among universities in Thailand, it was found that LGBTQIA+ rights were recognized in various ways at the majority of public universities. They all allow LGBTQIA+ students to wear uniforms that correspond to their gender. Chiang Mai University allows them to wear their uniform and graduation gown officially. [8]. Chiang Mai University (CMU)—one of Thailand’s leading public universities—has taken steps toward inclusion by recognizing student-led LGBTQ+ organizations and supporting gender-diverse policies in areas such as campus housing and uniform regulations. CMU hosts student groups like CMU Pride [9], which advocates for equality and provides peer support to sexuality-diverse students. While these efforts help foster a more inclusive environment, comprehensive diversity, equity, and inclusion (DEI) policies remain underdeveloped [10].

Additionally, the rise of social media has shaped students’ psychological experiences by offering mental health resources and online communities while also exposing sexuality-diverse students to cyberbullying and discrimination, which has negatively impacted their well-being [11]. Sexuality-diverse students in Thailand continue to face societal stigma, a lack of anti-discrimination laws, limited legal protections for transgender individuals, and discrimination in education and employment, all of which contribute to their mental health struggles [12].

Despite Thailand’s reputation for relative openness to sexual diversity, the country lacks strong legal protections and comprehensive advocacy for LGBTQ+ rights. Additionally, insufficient data exist on LGBTQ+ individuals’ access to education, healthcare, economic opportunities, and personal safety [13]. Social support plays a critical role in mitigating mental health issues for sexuality-diverse students. Research has suggested that support from family, friends, and educators is essential in promoting resilience and psychological well-being among LGBTQ+ students [14]. However, many students continue to experience discrimination and social isolation, which exacerbate mental health challenges.

Sexual identity development differs between straight and sexuality-diverse individuals. Research has suggested that LGBTQ+ individuals often experience complex and less predictable identity formation processes due to societal stigma, identity exploration, and unsupportive environments [15]. In contrast, straight individuals tend to follow more predictable developmental trajectories that align with societal norms and expectations. Despite these observed differences, limited research exists on sexual identity development in the Thai context.

Positive mental health outcomes have been closely linked to inner strength and resilience, which evolve over time based on environmental, social, and psychological factors [16]. Studies have suggested that resilience and inner strength vary across different sexual orientations and gender identities. However, no conclusive evidence exists of significant mental health disparities between straight and sexuality-diverse individuals [17]. Further research is needed to investigate these variations and develop targeted mental health interventions.

While extensive research has been conducted on LGBTQ+ mental health in Western contexts, studies in Southeast Asia, particularly Thailand, remain limited. Given differences in cultural values, social norms, and legal protections between regions, findings from Western settings may not fully apply to Thai society, where gender and sexual identities are increasingly recognized as fluid and non-binary [18]. Recent generational shifts have challenged rigid categorizations, with younger populations embracing diverse identities beyond traditional labels. However, stigma and structural barriers persist, disproportionately affecting sexual and gender minorities.

This study examines mental health disparities between heterosexual and sexuality-diverse university students in Thailand while acknowledging the spectrum of identities within LGBTQ+ communities. By focusing on both negative (e.g., depression, anxiety) and positive (e.g., resilience, social support) outcomes, we aim to identify gaps in support systems and highlight protective factors. Though our sample is limited to university students—a group often privileged in terms of education and socioeconomic status—the findings contribute to foundational knowledge for developing inclusive policies and mental health interventions. Ultimately, this research underscores the need for better societal adaptation, from academic institutions to broader community networks, to support the well-being of LGBTQ+ individuals in Thailand.

2. Materials and Methods

2.1. Study Design and Setting

This research utilized a cross-sectional survey approach to evaluate mental health outcomes among heterosexual and sexuality-diverse university students at Chiang Mai University (CMU) in Thailand. This study adhered to ethical standards and best practices concerning mental health research involving young adults. It aimed to uncover the disparities in both positive (resilience, inner strength, and perceived social support) and negative (depression, anxiety, and perceived stress) mental health outcomes across these different groups.

Baseline sociodemographic characteristics included age, sex, education level, relationship, income, parental attitude, parental marital status, parental occupation, history of mental health, social acceptance, and accepting and endorsing sexual stigma. The Attitudes Toward Lesbians and Gay Men Scale short version (ATLG-S), a five-item questionnaire with two sub-scales with each item rated on a seven-point Likert scale, was also used to assess social acceptance [19]. The Thai version of the Internalized Sexual Stigma Scale (IHP) is a five-item questionnaire. Each item is rated on a 4-point Likert scale to evaluate the acceptance and endorsement of sexual stigma [20].

Confounding factors (Covariates): Education level, income, age, sex, relationship, parental attitude, parental marital status, parental occupation, history of mental health, social acceptance, and accepting and endorsing sexual stigma.

2.2. Participants

A priori power analysis was conducted using STATA to determine the minimum required sample size for comparing two proportions of mental health outcomes. Based on estimates from prior research (25.9% for straight students and 45.4% for sexuality-diverse students) [21], with a desired power of 90% and a significance level of α = 0.01, the required sample size was calculated to be 178 participants per group. To account for potential attrition or data exclusion, an additional 20% buffer was added, resulting in a final target of 214 participants per group (total N = 428). This sample size was successfully achieved, ensuring sufficient statistical power to detect group differences. After the survey was completed, participants were thanked and provided with resources for mental health support. The finalized dataset was prepared for statistical analysis while maintaining all confidentiality and ethical standards throughout the process.

Participants were recruited through online university networks, student organizations, and academic departments, ensuring a diverse representation of sexual orientations. Of the 579 individuals who accessed the online survey, 572 agreed to participate. A total of 150 individuals were excluded: 5 were non-Thai, 118 were outside the eligible age range of 20–30 years, 8 were not enrolled at Chiang Mai University, and 19 (3.3%) were removed due to incomplete responses. This resulted in a final dataset comprising 442 participants whose results were valid. Data were reviewed for completeness before analysis.

This study included 442 university students aged 20–30 years from Chiang Mai University, Thailand. Participants were categorized into two groups: straight students (n = 229, 51.8%) and sexuality-diverse students (n = 213, 48.2%), which included individuals identifying as lesbian, gay, bisexual, and other non-heterosexual orientations. The sample consisted predominantly of female participants (71.5%), with male and non-binary individuals representing the remaining proportion. The mean age of the participants was 21.05 years (SD = ±2.43). The majority of students were enrolled in undergraduate programs (95.2%), with a smaller percentage pursuing graduate degrees. Regarding financial background, most students reported monthly expenditures below THB 7000 (52.7%), while others had moderate (THB 7000–10,000) or high (THB > 10,000) financial expenses. More than half (57.75%) of the participants had no prior history of mental health issues. Participants were recruited through online university networks, student organizations, and academic departments, ensuring a diverse representation of sexual orientations. Informed consent was obtained prior to participation, and ethical approval was granted by the Ethics Committee, Faculty of Humanities, Chiang Mai University, CMUREC 67/094. Additional demographic information is provided in

Table 1. Demographic information of the participants.

Characteristics of Participants		Frequency	Percentage
Sex	Female	316	71.5%
	Male	126	28.5%
Monthly Expenses	THB ≤ 7000	233	52.7%
	THB 7000–10,000	155	35.1%
	THB > 10,000	54	12.1%
Education Level	Bachelor’s Degree	421	95.2%
	Master’s Degree	19	4.3%
	Doctoral Degree	1	0.2%
Sexual Orientation	Straight	229	51.8%
	Sexuality Diverse	213	48.2%
LGBTQ+	Lesbian	22	5%
	Gay	46	10.4%
	Bisexual	123	27.8%
	Pansexual	15	3.4%
	Omnisexual	6	1.4%
	Queer	3	0.7%
	Non-Binary	1	0.2%
	Asexual	1	0.2%
	Missing Data	1	0.2%
Parents’ Occupation	Freelance	266	60.2%
	Company Employees	111	25.1%
	Government Employees	40	9%
	Educators	10	2.3%
	Unemployed	10	2.3%
	Retired/Uncomfortable Disclosing	5	1.1%
Parents’ Marital Status	Married	285	64.5%
	Remarriage	18	4.1%
	Divorced/Separated	139	31.4%
PATSO	Supportive	375	84.8%
	Unsupportive	66	14.9
	Missing Data	1	0.2%
HMHI	Anxious	110	24.9%
	Depressed	70	15.8%
	None	255	57.7%
	Stress/Both Anxious and Depressed	6	1.4%
	Missing Data	1	0.2%
Relationships	No	239	54.1%
	Yes	203	45.9%
Internalized Homophobia	Low Levels	343	77.6%
	Moderate Levels	94	21.3%
	High Levels	5	1.1%
ATLG	Low Negative Attitudes	349	79.0%
	Moderate Negative Attitudes	92	20.8%
	High Negative Attitudes	1	0.2%

Note. PATSO = parental attitude towards sexual orientation, ATLG = attitude toward lesbians and gay men, HMHI = history of mental health issues.

.

2.3. Procedure

Data were collected between May and August 2024 using an anonymous, self-administered online survey created in Microsoft Forms. The survey link was distributed through university networks and social media platforms to maximize outreach and accessibility. Multiple strategies were used to invite participants, including public postings on Facebook, targeted outreach on various social media channels, and engagement with LGBTQ+ community groups.

Although convenience sampling has limitations compared to probability sampling, such as reduced generalizability, it was the most practical approach for reaching a diverse range of participants, particularly those from under-represented sexual-diversity groups. This method enabled broad participation while upholding key ethical considerations, including participant anonymity and accessibility.

Ethical approval was granted by the Research Ethics Committee, Faculty of Humanities, Chiang Mai University. Eligibility criteria were limited to Thai nationals aged 20–30 years who were full-time students at Chiang Mai University. Screening criteria were embedded at the beginning of the survey to confirm eligibility.

The survey included demographic questions and validated instruments to assess both positive and negative mental health outcomes. These included the OI-21 for inner strength, the RI-9 for resilience, the Multidimensional Scale of Perceived Social Support (MSPSS), the Perceived Stress Scale (PSS-10), and the Internalized Sexual Behavior Inventory (ISBI) for depression and anxiety symptoms. Additionally, the Attitudes Toward Lesbians and Gay Men Scale–Short Version (ATLG-S) and the Internalized Homophobia Scale (IHP) were used to assess perceived social acceptance and internalized stigma, respectively.

Participants provided informed consent prior to participation. According to the principle of voluntariness, participants who accept and have informed consent can continue to participate in the questionnaire. Participants who do not accept the questionnaire will be prompted to end the questionnaire. Based on self-identified sexual orientation, participants define their own sexual orientation.

To maintain group balance, survey responses were monitored on a daily basis. When an over-representation of heterosexual respondents occurred, data collection from that subgroup was temporarily paused. Quality control mechanisms were embedded in the survey to detect and remove incomplete, inconsistent, or duplicate responses. At the conclusion of the survey, participants were thanked and provided with information on mental health resources. Only complete and valid responses were retained for final analysis, and all procedures adhered to ethical and confidentiality standards [22].

2.4. Measures

This study employed standardized psychological assessments and a demographic questionnaire to examine mental health outcomes among straight and sexuality-diverse university students. The demographic questionnaire collected key information, including university affiliation, education level, age (20–30 years), biological sex, sexual orientation, relationship status, parental attitudes, parental marital status, parental occupation, and mental health history. Participants outside the inclusion criteria were excluded. Validated psychological scales were used to assess psychological well-being. The Outcome Inventory (OI-21) (α = 0.92) assessed the level of anxiety and depression [23]. The Resilience Inventory (RI-9) (α = 0.89) assessed stress recovery [24], while the Inner Strength-Based Inventory (ISBI) (α = 0.68) evaluated inner psychological strength [25]. The Internalized Sexual Stigma Scale (IHP, Thai version) (α = 0.83) measured levels of internalized stigma in sexuality-diverse individuals [20], and the Multidimensional Scale of Perceived Social Support (MSPSS, Thai version) (α = 0.93) assessed perceived emotional and practical support from family, friends, and significant others [26]. Stress levels were evaluated using the Perceived Stress Scale (PSS-10) (α = 0.72) [27], while attitudes toward sexuality-diverse individuals were assessed using the Attitudes Toward Lesbians and Gay Men Scale (ATLG) (α = 0.74) [28], which was translated into Thai and validated before use. Assessments were administered via Microsoft Forms, with tailored questions tailored to individual sexual orientations. Pilot testing ensured feasibility and an automated verification system prevented fraudulent responses. Data collection was monitored daily to maintain a balanced recruitment process, and incomplete responses were excluded to ensure data integrity.

2.5. Data Analysis

Analyses were conducted using SPSS 26.0 (IBM Corp., Armonk, NY, USA). Descriptive statistics summarized mental health variables, and an independent sample t-test assessed group differences. Multiple regression analyses identified predictors of mental health outcomes, controlling for confounders (p < 0.05).

Linear regression was applied to continuous outcomes, incorporating significant correlates identified in prior analyses. Three models controlled for increasing factors: (1) demographic and socioeconomic variables, (2) attitudes toward LGBTQ+ individuals and internalized homophobia, and (3) additional parental factors. Missing data were handled by listwise deletion to ensure that analyses were based solely on complete and fully engaged participants, thereby enhancing the validity and consistency of the comparisons. Effect sizes were calculated to assess practical significance.

3. Results

3.1. Confounders Associated with Straight and Sexuality Diverse

Table 2. Characteristics of sexuality-diverse and straight groups.

Participants’ Characteristics		Sexuality-Diverse Group (n = 213)	Straight Group (n = 229)	p-Value
Age	20–25	47.3%	49.8%	0.202
	26–30	0.9%	2.0%
Sex	Male	14.7%	13.8%	0.367
	Female	33.5%	38.0%
Monthly expenses	THB ≤ 7000	26.0%	26.7%	0.668
	THB 7000–10,000	17.0%	18.1%
	THB ≥ 10,000	5.2%	7.0%
Education	Bachelor’s Degree	46.4%	49.1%	0.539
	Master’s Degree	1.8%	2.5%
	Doctoral Degree	0.0%	0.2%
Parent’s occupation	Freelance	29.0%	31.2%	0.038
	Company Employees	4.8%	4.3%
	Government Employees	1.8%	0.5%
	Educators	10.4%	14.7%
	Unemployed	1.1%	1.1%
	Retired/Uncomfortable Disclosing	1.1%	0.0%
Parent’s marital status	Married	29.4%	35.1%	0.159
	Remarriage	2.7%	1.4%
	Divorced/Separated	16.1%	15.4%
PATSO	Supportive	38.1%	46.9%	<0.001
	Unsupportive	10.2%	4.8%
HMHI	Anxious	12.5%	12.5%	0.652
	Depressed	8.2%	7.7%
	None	26.8%	31.1%
	Stress/Both Anxious and Depressed	0.9%	0.5%
Relationship	No	27.8%	26.2%	0.135
	Yes	20.4%	25.6%
Internalized homophobia	Low Levels	41.0%	36.7%	0.001
	Moderate Levels	7.0%	14.3%
	High Levels	0.2%	0.9%
ATG	Low Negative Attitudes	43.4%	36.0%	<0.0001
	Moderate Negative Attitudes	4.8%	15.4%
	High Negative Attitudes	0.0%	0.5%
ATL	Low Negative Attitudes	42.5%	36.4%	<0.0001
	Moderate Negative Attitudes	5.7%	15.2%
	High Negative Attitudes	0.0%	0.2%

Note. ATG = attitude towards gay, ATL = attitude towards lesbian, PATSO = parental attitude towards sexual orientation, HMHI = history of mental health issues.

compares demographic and confounding factors between sexuality-diverse and straight students. Most variables show no significant differences (p > 0.05), except for parents’ occupations, parental attitudes toward sexual orientation, attitudes toward gay and lesbian individuals (ATG and ATL), and internalized homophobia (IHP). Sexuality-diverse students’ parents tend to have more positive attitudes (p < 0.05), while straight students exhibit more positive attitudes toward sexual minorities and lower internalized homophobia (p < 0.05).

3.2. Sexual Orientation and Mental Health Outcomes

Table 3. Prevalence of mental health outcomes and association of with sexual orientation.

Mental Health Outcomes	Sexuality-Diverse Group (n = 213)	Straight Group (n = 229)	t	p-Value
Anxiety (Mean ± SD)	8.99 ± 5.17	8.75 ± 4.96	−0.48	0.627
Low	68 (15.4)	74 (16.7)
Moderate	132 (29.9)	145 (32.8)
High	13 (6.1)	10 (4.4)
Depression	4.81 ± 4.34	3.94 ± 3.70	−2.25	0.025
Low	137 (31.6)	156 (35.9)
Moderate	69 (15.9)	71 (16.4)
High	7 (1.6)	2 (0.5)
Perceived Stress	18.42 ± 6.49	18.53 ± 5.99	0.18	0.852
Low	44 (10.0)	43 (9.7)
Moderate	149 (33.7)	166 (37.6)
High	20 (4.5)	20 (4.5)
Resilience	34.01 ± 6.33	34.75 ± 6.15	1.24	0.213
Low	0 (0)	0 (0)
Moderate	117 (26.5)	102 (23.1)
High	96 (21.7)	127 (28.7)
Inner Strength	30.69 ± 5.06	31.15 ± 5.09	0.95	0.339
Low	0 (0)	1 (0.2)
Moderate	202 (45.7)	212 (48.0)
High	11 (2.5)	16 (3.6)
Perceived Social Support	5.00 ± 1.38	5.32 ± 1.17	2.63	0.009
Low	18 (4.2)	7 (1.6)
Moderate	75 (17.5)	76 (17.8)
High	113 (26.4)	139 (32.5)

Note. SD = standard deviation, t = t-statistic.

presents differences in mental health outcomes by sexual orientation. Sexuality-diverse participants had a higher mean depression score (4.81 ± 4.34) than straight participants (3.94 ± 3.70), though both groups were mostly in the low-depression range. Perceived social support was lower among sexuality-diverse participants (5.00 ± 1.38) compared to straight participants (5.32 ± 1.17). Depression (t = −2.25, p < 0.05) and perceived social support (t = 2.63, p < 0.05) differed significantly between the groups.

3.3. Negative Mental Health Outcomes and Positive Mental Health Outcomes

Table 4. Correlation between anxiety, depression, perceived stress, resilience, inner strength, and perceived social support.

	Anxiety	Depression	Perceived Stress	Resilience	Inner strength
Anxiety
Depression	0.73 **
Perceived Stress	0.68 **	0.62 **
Resilience	−0.38 **	−0.43 **	−0.47 **
Inner Strength	−0.22 **	−0.27 **	−0.29 **	0.46 **
Perceived Social Support	−0.33 **	−0.35 **	−0.36 **	0.33 **	0.20 **

Note. ** Correlation is significant at the 0.01 level (2-tailed).

highlights strong positive correlations between anxiety and both depression (r = 0.73) and perceived stress (r = 0.68), indicating that higher anxiety is linked to increased depression and stress. Conversely, resilience (r = −0.38), inner strength (r = −0.22), and perceived social support (r = −0.33) exhibit negative correlations with anxiety, suggesting that they may help reduce it. Similarly, depression correlates positively with perceived stress (r = 0.62) and negatively with resilience (r = −0.43), inner strength (r = −0.27), and social support (r = −0.35). Perceived stress follows the same pattern, negatively correlating with resilience (r = −0.47), inner strength (r = −0.29), and social support (r = −0.36). Additionally, resilience, inner strength, and social support show positive intercorrelations. Overall, strong social support plays a key role in reducing anxiety, depression, and stress while enhancing resilience and inner strength, emphasizing the importance of fostering supportive networks for student mental health.

3.4. Negative Mental Health Outcomes and Positive Mental Health Outcomes

The regression analysis in

Table 5. Association between adverse mental health outcomes and sexual orientation after controlling for confounding factors.

Outcomes	Anxiety			Depression			Perceived Stress
Predictor	Model 1	Model 2	Model 3	Model 1	Model 2	Model 3	Model 1	Model 2	Model 3
Sexual Orientation (B)	0.019	0.020	0.021	0.097 *	0.104 *	0.115 *	−0.006	0.023	0.011
R2	0.060	0.031	0.091	0.084	0.109	0.124	0.041	0.061	0.077
ΔR2	0.06			0.015			0.016

Note. B = unstandardized coefficients; R² = explained variance; ΔR² = change in explained variance after adding predictors. * Statistically significant (p < 0.05). Sexual orientation is coded as 0 = straight, 1 = sexuality diverse. Model 1 adjusted for age, relationships, education, monthly expenses, history of mental health issues, and sex. Model 2 adjusted for Model 1 plus attitude towards gay and lesbian individuals, internalized homophobia. Model 3 was adjusted for Models 1 and 2, as well as parents’ occupation, parental marital status, and parental attitude towards sexual orientation.

and

Table 6. Association between positive mental health outcomes and sexual orientation after controlling for confounding factors.

Outcomes	Resilience			Inner Strength			Perceived Social Support
Predictor	Model 1	Model 2	Model 3	Model 1	Model 2	Model 3	Model 1	Model 2	Model 3
Sexual Orientation (B)	−0.062	−0.043	−0.043	−0.049	−0.055	−0.045	−0.105 *	−0.118 *	−0.100 *
R2	0.022	0.034	0.043	0.019	0.034	0.038	0.085	0.096	0.110
ΔR2	0.009			0.004			0.014

Note. B = unstandardized coefficients; R² = explained variance; ΔR² = change in explained variance after adding predictors. * Statistically significant (p < 0.05). Sexual orientation is coded as 0 = straight, 1 = sexuality diverse. Model 1 adjusted for age, relationships, education, monthly expenses, history of mental health issues, and sex. Model 2 adjusted for Model 1 plus attitude towards gay and lesbian individuals, internalized homophobia. Model 3 was adjusted for Models 1 and 2, as well as parents’ occupation, parental marital status, and parental attitude towards sexual orientation.

reveals significant mental health differences between straight and sexuality-diverse students, particularly in depression and perceived social support.

3.4.1. Depression and Sexual Orientation

Sexuality-diverse students consistently report higher depression levels across all models (Model 1: B = 0.097, p < 0.05; Model 2: B = 0.104, p < 0.05; Model 3: B = 0.115, p < 0.05). These findings align with minority stress theory, highlighting the need for targeted mental health interventions.

3.4.2. Perceived Social Support and Sexual Orientation

Sexuality-diverse students report significantly lower social support (Model 1: B = −0.105, p < 0.05; Model 2: B = −0.118, p < 0.05; Model 3: B = −0.1, p < 0.05), increasing their mental health risks. Strengthening peer support networks and promoting family acceptance initiatives could help mitigate these challenges.

4. Discussion

This study compared mental health outcomes between straight and sexuality-diverse university students in Thailand. It explored positive factors such as inner strength, resilience, and perceived social support while also assessing negative outcomes like depression, anxiety, and perceived stress. This study identified mental health disparities between the groups, aligning with global research on LGBTQ+ well-being and highlighting unique challenges faced by sexuality-diverse students in Southeast Asia.

Interestingly, no significant difference in resilience was found between straight and sexuality-diverse students, suggesting similar coping abilities despite mental health disparities. Resilience, a key protective factor against perceived stress, anxiety, and depression [29], helps individuals adapt to adversity. This aligns with research indicating that LGBTQ+ individuals benefit from social support networks that enhance resilience [30,31]. In Thailand, LGBTQ+ student groups and community resources likely contribute to this resilience [32]. However, societal and familial pressures may undermine confidence in identity, highlighting the need for interventions to strengthen self-esteem and identity development [33]. Resilience is linked to lower anxiety, depression, and perceived stress, yet sexuality-diverse students may experience reduced resilience due to minority stress and internalized stigma, weakening its protective effects [11].

The findings support the idea that perceived social support plays a crucial role in mental health, with higher support linked to lower anxiety, depression, and perceived stress, as well as greater resilience and inner strength. Social support helps mitigate minority stress [34,35]. Yet sexuality-diverse students in Thailand may struggle to access it due to traditional family structures. Alternative sources, such as peer networks and spirituality, may aid resilience, though further research is needed [36]. Cultural expectations around family, religion, and societal roles can create challenges for LGBTQ+ individuals [12], underscoring the need for culturally sensitive mental health interventions to foster supportive environments.

Sexuality-diverse students reported significantly higher depression levels than their straight peers, aligning with minority stress theory, which links stigma and discrimination to mental health challenges [11,37]. Despite Thailand’s reputation for LGBTQ+ tolerance, deep-rooted cultural norms uphold heteronormativity, contributing to alienation [12]. While most parents in this study were supportive, some were not, reflecting the complex reality of acceptance. Research highlights the contrast between Thailand’s perceived inclusivity and the actual stigmatization faced by LGBTQ+ individuals, particularly in education [38]. These societal pressures likely contribute to the heightened anxiety, depression, and stress observed among sexuality-diverse students [33].

The findings revealed that sexuality-diverse students reported lower levels of resilience and inner strength compared to their heterosexual peers. Resilience, which embodies an individual’s empowerment, self-assurance, and capacity to overcome life’s challenges [39], seemed to be diminished among sexuality-diverse students. While this difference did not reach statistical significance (p = 0.213, Table 3), it signals a potential area for further exploration.

Sexuality-diverse students exhibited higher levels of internalized homophobia (IHP) than their straight peers, with 41.0% reporting low IHP, while 36.7% of straight students showed moderate-to-high levels (p = 0.001). They also held more positive attitudes toward sexual minorities (p < 0.001). Parental support varied significantly, with fewer sexuality-diverse students (38.1%) reporting supportive parents compared to straight students (46.9%, p < 0.001), while a greater proportion faced unsupportive parental attitudes (10.2% vs. 4.8%). These findings align with the psychological mediation framework, suggesting that stigma and discrimination diminish resilience and self-esteem, leading to poorer mental health outcomes [40,41].

Mental health disparities were evident, particularly in depression and perceived social support. Sexuality-diverse students reported significantly lower social support across all models (Model 1: B = −0.105, p = 0.024; Model 2: B = −0.118, p = 0.016; Model 3: B = −0.100, p = 0.045), possibly due to peer rejection, institutional discrimination, or internalized stigma [13]. Sexual orientation also emerged as a significant predictor of depression (B = 0.115, p = 0.020), even after adjusting for demographic factors, reinforcing evidence that LGBTQ+ youth face heightened depression risks due to minority stress [42]. While anxiety and stress differences were less pronounced, sexuality-diverse students consistently reported higher mean scores (anxiety: 8.99 ± 5.17 vs. 8.75 ± 4.96; depression: 4.81 ± 4.34 vs. 3.94 ± 3.70; perceived stress: 18.42 ± 6.49 vs. 18.53 ± 5.99, Table 3), reflecting the cumulative burden of navigating a heteronormative society.

Unlike previous research emphasizing discrimination’s negative effects [20], this study highlights protective factors such as resilience and inner strength. Despite reporting lower perceived social support (p = 0.009, Table 3), sexuality-diverse students exhibited resilience levels comparable to their straight peers, suggesting that coping strategies and community support may buffer the psychological effects of minority stress. These findings expand on previous studies by empirically demonstrating how variations in social support influence the mental health of university students in Thailand [38].

Furthermore, the increasing visibility and acceptance of gender and sexual fluidity among younger generations challenged the traditional binary categories used in this study. While this research classified participants as either heterosexual or sexuality-diverse, emerging identities and non-binary orientations suggested the necessity for more inclusive approaches in future research. The coexistence of masculine and feminine traits within individuals, along with the growing recognition of non-traditional labels, indicated that sexuality and gender are increasingly becoming fluid constructs [43]. Understanding this complexity is essential for accurately capturing the lived experiences and mental health realities of LGBTQ+ youth. Researchers are encouraged to consider broader, more flexible identity frameworks that reflect these evolving social norms, thereby avoiding oversimplification and misrepresentation.

Additionally, although Chiang Mai University provided a culturally diverse and relatively inclusive environment, it did not represent the broader Thai population. University students—especially those from prominent institutions—tend to come from more socioeconomically advantaged backgrounds, which could influence their access to mental health resources and social support. This limitation hindered the generalizability of the findings to LGBTQ+ individuals from rural areas or lower educational strata, whose experiences might have differed significantly due to social and economic constraints [44]. Broader sampling across various regions and educational contexts is necessary to obtain a fuller understanding of the mental health challenges faced by sexuality-diverse populations in Thailand.

Furthermore, the increasing visibility and acceptance of gender and sexual fluidity among younger generations challenge the traditional binary categories used in this study. While our analysis compared heterosexual and sexuality-diverse students, emerging identities (e.g., non-binary, pansexual, asexual) highlight the need for more nuanced frameworks in future research. The coexistence of masculine and feminine traits within individuals, alongside the growing rejection of rigid labels, underscores that sexuality and gender exist along a spectrum [18]. To fully capture the mental health realities of LGBTQ+ youth, studies must adopt flexible, inclusive measures that reflect these evolving social norms. This shift is crucial to prevent oversimplification and ensure that marginalized identities are accurately represented.

Additionally, although our sample provided valuable insights into the experiences of university students, its generalizability is limited. Participants from Chiang Mai University—a prestigious institution—likely represent more privileged socioeconomic backgrounds, with greater access to mental health resources and peer support compared to LGBTQ+ individuals in rural or low-income communities.

4.1. Implications

The findings of this research suggest that university students who identify as sexuality diverse face a greater risk of mental health disparities, especially depression and lower perceived social support, compared to their heterosexual counterparts. These disparities underscore the need for targeted mental health initiatives and policy measures that address the specific challenges faced by this group.

Given the heightened vulnerability of sexuality-diverse students to depression and lower social support, universities and policymakers need to adopt targeted mental health interventions to address these disparities. Suggested initiatives include improving LGBTQ+-inclusive mental health services by educating mental health practitioners on LGBTQ+ cultural competence; establishing peer mentorship programs to bolster social support networks for sexuality-diverse students; introducing family acceptance programs to inform families about the importance of supporting their LGBTQ+ children; and reinforcing anti-discrimination policies within universities to foster safer and more inclusive educational environments.

4.2. Limitations

This study had several limitations that should be considered when interpreting the findings. First, the sample was restricted to university students in Thailand, specifically at Chiang Mai University. While CMU is relatively progressive and diverse, the experiences of its students may not accurately reflect those in other institutions or regions, particularly in more conservative or rural contexts. As such, the findings may not be generalizable to the broader sexuality-diverse population across different age groups, educational settings, or geographic areas. Future studies should prioritize intersectional approaches that examine how class, geography, and education intersect with sexual and gender identity to compound or alleviate minority stress.

Second, the cross-sectional design limits the ability to infer causality between sexual orientation and mental health outcomes. Longitudinal research is necessary to investigate how these relationships develop over time and under varying social contexts.

Third, this study employed convenient sampling to recruit participants, which, while effective in reaching sexuality-diverse individuals, may have introduced selection bias. Those more connected to LGBTQ+ networks or more comfortable discussing their identity may have been more likely to participate. This could limit the diversity and representativeness of the sample despite efforts to maintain group balance and verify the authenticity of responses.

Fourth, the reliance on self-reported measures may have introduced bias due to social desirability or inaccurate recall. Participants may have under-reported or over-reported their symptoms of depression, anxiety, or perceived social support, affecting the validity of the results.

Fifth, unmeasured confounding variables may have influenced the results. While the study controlled several sociodemographic and psychosocial factors, other important influences, such as direct experiences of discrimination, religiosity, or academic pressure, were not accounted for.

Lastly, cultural factors unique to the Thai context, such as the influence of Buddhism or prevailing societal norms around gender and sexuality, may have shaped the experiences of participants in ways not fully addressed by the study instruments. Future research should delve more deeply into these dimensions to enhance cultural specificity and contextual relevance.

To address these limitations, future studies should employ longitudinal and mixed methods designs, recruit from a more diverse set of institutions and regions, and consider randomized or stratified sampling techniques. Incorporating additional contextual variables would also provide a more comprehensive understanding of the mental health disparities experienced by sexuality-diverse students in Thailand.

5. Conclusions

This study emphasizes the differences in mental health outcomes between straight and sexuality-diverse students in Thailand. Sexuality-diverse students experience higher levels of anxiety, depression, and perceived stress due to a lack of social support. To address the mental health needs of sexuality-diverse students, it is crucial to build resilience, promote family and peer support, and create inclusive environments. Communities and governments should pay special attention to the unique challenges faced by sexuality-diverse students to ensure their psychological well-being is adequately supported as they continue to promote mental health awareness.