Depressivity, Parental Cohabitation, and Sex as Determinants of Physical Self-Harm During Adolescence

Abstract

Objective: This study focuses on selected potential determinants of self-harm in adolescents of two age groups. The considered factors are depression, sex, and parental cohabitation. The aim of the study is to reveal the association between the mentioned factors and self-harm in younger and older adolescents. A secondary goal is to identify the prevalence of self-harm in two age groups. Self-harm is defined as the repeated occurrence of its physical forms. Methods: In the non-experimental research study, the respondents (N = 1285) were primary and secondary school pupils from Slovakia and made up two age cohorts (12–15 and 16–18 y). A battery of questionnaires consisted of the CDI, Self-Harm Inventory and a demographic questionnaire. Procedures of statistical analysis including the logistic regression were applied for data processing. Results: Depression as a risk factor for physical forms of self-harm was recognised in both age cohorts. In terms of sex as a predictor (girls), it proved to be a strong determinant of development of self-harm in the younger group. Conclusions: The results demonstrate the relevance of the need for a separate study of self-harm in boys and girls, as well as in the context of developmental peculiarities in adolescence.

1. Introduction

Self-harm is a self-destructive behaviour that expresses mental suffering, which may have long-term, in-depth effects on quality of life [1,2]. Several research studies (e.g., [3,4,5,6,7,8,9]) confirmed the association between physical self-harm and specific risk factors. Despite this, it is impossible to define a universal normality. The study at hand intends to examine the emotional experiencing, relationships, and the living arrangements of the adolescents’ family unit, in the sense of a complete nuclear family or separated parents. Research into these issues is backed up by the results of many other studies [7,10,11,12,13] and through clinical practice. The aetiology of the development of self-harm stems from hidden problems of an intrapsychic nature, mainly in the area of emotional relationships [14,15,16,17,18]. The analysis of an individual problem often uncovers a fundamental aspect of a latent problem, and the physical pain is considered to be a reaction to mental suffering. In relation to this, Hicks and Hinck [11], state that the control of psychological pain is problematic, whereas physical pain can be controlled through a set course of action. The conviction that the suffering caused by mental pain is unbearable may also lead to compensation through physical forms of self-harm [1,19]. Mental pain, therefore, represents an emotional injury [20,21,22,23], while the intensity of the injury is reflected in the emotionally affective experiences [13,24]. Emotional experience has a fundamental influence on emotional regulation and relief may be found through both adaptive and maladaptive behaviour [3,25,26]. Self-harm is one of the forms of maladaptive behaviour, and it is a source of negative, sometimes traumatic emotions, information, and experience [4,7,11,15]. Besides emotional experiences (through emotional and social relationships), biochemical and hormonal processes also affect perceptions and feelings in the period of adolescence [17,27]. These can direct the coping process into adaptation but can also introduce significant problems, which may result in self-harm [5,6,28,29].

The study considers self-harm as a consequence of emotional problems during adolescence (an intrapsychic conflict can manifest itself in behaviour as a latent form of aggression followed by anxious experience [8,21,30] and result in self-harm). The investigation into the psychological sources of negative emotions focused on the family living arrangements (specifically, parental cohabitation or separation) and emotional experiences (the presence of depressive symptomatology) [14,18,22,26,31]. The link between emotional problems such as depressivity and self-harm has been demonstrated by many studies (e.g., [25,32,33,34,35]), whereas the development of depressive symptomatology is conditioned by, with the exception of emotional problems [36,37], chronic stressors [21,29,31], the specific living conditions, specific factors of risk behaviour [22,38], social support and interparental relationships [1,7,39,40], family interactions [16,24,26,36], and personality [3,37]. Episodes of depressive behaviour tend to be observed as early as in pre-school-aged children; however, their incidence grows during adolescence. In the period of 11 to 14, childhood depression begins to occur more frequently, and its incidence peaks in the middle of adolescence [1,4].

Coping with problems and emotionally processing them in adolescence is more difficult for girls in comparison to boys [21]. Experts [24,26] emphasise the significance of parental support in the process of the development of depression and anxiety in adolescents, where depressive symptomatology can be a consequence of psychological and behavioural difficulties [18,23,41]. Similarly, we can find conformity with the fact in current knowledge [16,37,42,43] that depressive symptomatology forms a comorbidity with several mental disorders, while the symptomatology in children does not need to match the clinical definition of depression. The symptoms may manifest as a problem with interpersonal relationships, a lack of energy, a lowered sense of self-worth, a negative emotional balance that results in a lower ability to experience pleasure, a damaged self-image, etc. An important criterion for stating the presence of depressive symptomatology is its manifestation for a period of at least two months up to one year [44].

From the presented spectrum of risk factors, we specified the following as predictors for the proposal to investigate physical forms of self-harm: depressivity, form of parental coexistence (cohabitation/separate), sex, and all for both age groups (younger and older adolescents).

Objectives

• To describe singular and repeated occurrences of specific forms of physical self-harm in the younger (12–15 years old) and older (16–18 years old) cohorts of adolescents.
• To uncover the differences in the effect of selected factors (depressivity, sex, and parental cohabitation) on the occurrence of physical self-harming behaviour (Physical SH) between the group of younger and older adolescents.
• To specify the individual effect of predictors (increased depressivity, the absence of a parent in the family environment, sex (girls)) on Physical SH within a regression model for the younger and older group of adolescents and to uncover the differences in significance and in odds ratio of predictors between age cohorts.

2. Methods

2.1. Research Sample

The research was conducted using data from a sample of adolescents from various regions of Slovakia. The research sample consisted of 1285 adolescents, N = 826 girls (average age 15.2) and N = 459 boys (average age 15.7). The sample was divided into two cohorts: 12–15 (N = 628, average age 14.9) and 16–18 (N = 657, average age 17.4). The sample splitting was performed in order to meet the objectives taking into account the developmental specificities of self-harm and the symptomatology of depression in the earlier and later stages of adolescence. The selection of schools was carried out using a convenience sampling method, with an emphasis on regional diversity and school type (primary/secondary). Within each participating school, data collection was conducted in classroom settings, where the response rate was 92%. Schools from both rural and urban areas were intentionally included to partially enhance the representativeness of the data and to minimise potential regional bias.

An important criterion differentiating the sample was the occurrence of Physical SH, which is defined as repeated experience with a physical self-harm (the operationalisation of this will be described in later sections). In the entire sample, Physical SH was detected in 32.8% (N = 442) of respondents, 35.7% (N = 224) in the 12–15 cohort and 30.1% (N = 198) in the 16–18 cohort. A singular occurrence of self-harm was found in 17.3% of the total sample, 15.4% of the 12–15 cohort and 19.0% of the 16–18 cohort. Respondents who reported singular occurrences were excluded from the investigation and the comparison was examined between respondents with Physical SH (Group Yes) and respondents without any Physical SH (Group No). The total sample was used for description of specific physical self-harm form prevalence in the categories of repeated and singular occurrence.

2.2. Data Collection and Analyses

The used battery of questionnaires consisted of the Children’s Depression Inventory (CDI) (Kovacz, amended by Preiss, [45]) and the Self-Harm Inventory—the SHI [46] which was modified for the Slovak population by Demuthova [1,4]. The modification of the SHI included the deletion of certain items (inappropriate for young adolescents), the addition of certain items (based on previous qualitative questioning), and the addition of a question of frequency to the answer scale (to distinguish rare occurrences from repeated self-harm). The questionnaire also contained a section with demographic items to obtain data on the form of parental cohabitation, the age, and sex of the respondent (and other factors, not used in this study). The questionnaire was administered following correct ethical principles (anonymity, parental consent, the formulation of questions in such a way as to avoid traumatising the respondents).

In terms of categorisation, self-harm is understood as a repetitive rather than a one-time behaviour. This concept is based on a common feature shared by existing theoretical approaches, which—although they differ in their understanding of the forms of self-harm (see, e.g., the narrower definition in the DSM-5 [47] versus the broader ones by Sansone & Sansone [46] or, more recently, by Liljedahl et al. [48])—are unified in recognising the repetitive nature of this behaviour. It is also characteristic of adolescents that they may change the forms of self-harm according to actual circumstances. Based on this, respondents were placed into the category of physical self-harming behaviour (group Physical SH Yes) if they reported at least one form of physical self-harm (deliberate hitting, head-butting, burning, cutting, scratching, or other injuries), together with an indication reflecting repeated experience with one form of Physical SH, or if they reported at least three non-zero experiences in at least three different forms of physical self-harm. Respondents who reported no experience in any of the six items describing physical forms of SH were included in the group Physical SH No, and the third group consisted of respondents who reported a rare experience of physical self-harm (Singular occurrence of Physical SH group). The variable parental cohabitation is represented by two categories: parents living together and parents living separately. If the respondent selected the answer “Other situation” (e.g., a deceased parent, two fathers, parents living together but also with a new partner, etc.), it was not categorised (missing data, n = 49; 3.8%). Depressivity was measured using the Children’s Depression Inventory (CDI) [45]—the tool commonly used in the clinical practice for screening the depressive symptomatology, standardised for the Slovak adolescent population. For research purposes, raw scores of 5 scales were used (anhedonia, bad mood, ineffectiveness, negative self esteem, interpersonal problems) and the total depressivity score was also included in the analysis.

For analyses, univariate and bivariate statistical descriptions (frequency analysis) and comparative statistical inference procedures (t-test, Chí-square) were applied. Physical SH was considered as the consequence of predictors (depressivity, cohabitation vs. absence of a parent, sex) and based on these specifications, a binary logistic regression was executed.

3. Results

To achieve the first objective, we executed a frequency analysis of the individual forms of physical self-harm. The relative frequencies (%) of “Singular occurrence” and “Repeated occurrence” for cutting, burning, hitting, banging the head, scratching and other injuries within the total sample and separately for the two age cohorts are presented in Table 1. Overall, but also in the individual cohorts, the most frequent form of physical self-harm (singular + repeated occurrence) is scratching (31.4% of the total sample, 32.9% of the 12–15 group and 29.2% of the 16–18 group) followed by hitting (30.1% of the total sample, 30.9% of the 12–15 group and 29.4% of the 16–18 group). The least frequent form of physical self-harm was burning (9.6% of the total sample, 9.3% of the 12–15 group, and 9.9% of the 16–18 group).

Table 1. Description of the categories of Physical SH and its forms, and singular occurrence of physical self-harm in the total sample and the two age cohorts (12–15 and 16–18).

		Total		12–15 Yrs Old		16–18 Yrs Old
		N	%	N	%	N	%
Physical SH	No	641	49.9	307	48.9	334	50.8
	Yes	422	32.8	224	35.7	198	30.1
	Cutting	164	12.8	81	12.9	83	12.6
	Burning	46	3.6	28	4.5	18	2.7
	Hitting	193	15	107	17	86	13.1
	Banging the Head	111	8.6	67	10.7	44	6.7
	Scratching	198	15.4	110	17.5	88	13.4
	Injuring	170	13.2	98	15.6	72	11
Singular occurrence of physical self-harm		222	17.3	97	15.5	125	19.0
Cutting		156	12.1	81	12.9	75	11.4
Burning		77	6	30	4.8	47	7.2
Hitting		194	15.1	87	13.9	107	16.3
Banging the Head		176	13.7	84	13.3	92	14
Scratching		205	16	97	15.4	108	16.4
Injuring		134	10.4	56	8.9	78	11.9
	Total	1285		628		657

Firstly, to address objective two, a statistical comparison of the subscales and the total score for depressivity was performed, comparing the group with Physical SH (Yes) and without Physical SH (No). A Student’s t-test was carried out for the individual age groups (12–15 and 16–18), respectively. The results of the t-test, as shown in Table 2, indicate significant differences in all the depressivity subscales (interpersonal problems, ineffectiveness, bad mood, anhedonia, and a negative self esteem) as well as the Depressivity total score, at a significance level of p < 0.001, for both the younger (12–15) and older (16–18) age groups. Individuals indicate incidences of self-harm score higher on the subscales, in both age cohorts.

Table 2. Binary comparison of depressivity (total score and subscales) between the group with Physical SH and the group without Physical SH, in two age cohorts.

Age Group		Physical SH	AM	SD	Student’s t-Test	Cohen’s d
12–15 yrs old	Bad mood	YES	4.95	2.48	13.553 **	1.263
		NO	2.23	1.88
	Interpersonal problems	YES	2.08	1.45	10.854 **	1.008
		NO	0.80	1.12
	Ineffectiveness	YES	3.54	1.77	9.444 **	0.841
		NO	2.10	1.67
	Anhedonia	YES	5.88	2.71	13.302 **	1.222
		NO	2.88	2.25
	Negative self esteem	YES	4.00	2.02	13.928 **	1.308
		NO	1.79	1.40
	Depressivity total	YES	20.18	8.22	14.815 **	1.438
		NO	9.84	6.35
16–18 yrs old	Bad mood	YES	4.58	2.51	9.674 **	0.958
		NO	2.55	1.85
	Interpersonal problems	YES	1.85	1.50	8.176 **	0.799
		NO	0.84	1.10
	Ineffectiveness	YES	3.30	1.81	6.709 **	0.61
		NO	2.26	1.64
	Anhedonia	YES	5.81	2.99	8.078 **	0.785
		NO	3.76	2.36
	Negative self esteem	YES	3.58	2.43	8.940 **	0.924
		NO	1.83	1.49
	Depressivity total	YES	19.07	9.10	9.907 **	1.153
		NO	11.28	6.61

Note: ** p < 0.001.

Secondly, also to address objective two, a Chi-square test complemented with an odds ratio evaluation (for 2 × 2 table) was used to explore significant differences in the frequency of the occurrence of Physical SH between the groups of adolescents with regard to the form of parental cohabitation and sex. The test results are shown in Table 2. Within the younger age group (12–15), we observe a significant difference in the frequency of Physical SH with regard to parental cohabitation (p < 0.001). There was a higher count of self-harm in the group whose parents live separately (58.2%) compared to the group whose parents live together (35.3%). In regard to the OR, the chance that an adolescent reports Physical SH is 2.549 times higher in those whose parents live separately in comparison to those whose parents live together. In the older age group (16–18), we also identified a significant difference (p < 0.01), where the higher percentual count of Physical SH is registered in adolescents whose parents live separately (45.3%), in comparison with the group without an absent parent (33.9%). According to the OR, an adolescent with an incomplete family (parents living separately) has a 1.619 times higher chance of Physical SH, than those whose parents live together. Having an incomplete family (the absence of one parent from the family environment) is considered to be a risk factor for physical self-harming behaviour in the younger age group (12–15).

Furthermore, the difference in the occurrence of Physical SH between boys and girls was also investigated for both age cohorts. The test results are shown in Table 3. In the younger age group, there are significantly higher values of Physical SH in girls (51.7%) in comparison to boys (29.9%). In the older age group, no statistically significant difference in Physical SH between boys and girls (p > 0.05) was found. In the younger age cohort (12–15 years old), there is a 1.570 times higher chance of Physical SH for girls than boys.

Table 3. Binary comparison of the SH occurrence between subgroups (sex, parental cohabitation) within the total sample and separately for the two age cohorts.

			Physical SH		Pearson’s Chí-Square
Group			N	%	χ2	OR a
Total sample			422	39.7
12–15 yrs old	Sex	Girls	155	51.7	25.422 **	2.510
		Boys	69	29.9
	Parental cohabitation	Parents living separately	71	58.2	20.061 **	2.549
		Parents living together	136	35.3
16–18 yrs old	Sex	Girls	146	37.1	0.017	0.974
		Boys	52	37.7
	Parental cohabitation	Parents living separately	63	45.3	5.731 *	1.619
		Parents living together	128	33.9

Notes: ^a OR for 2 × 2 table; * p < 0.01; ** p < 0.001.

Furthermore, a binary logistic regression analysis was conducted in order to address Objective 3. The results are shown in Table 4. Physical SH is considered to be a consequence of certain predictors: depressivity (total score), sex (OR for the group of girls is interpreted), and parental cohabitation (OR for the category parents living separately is interpreted). In accordance with the results of the bivariate analysis, the regression analysis also found that depressivity and sex were significant predictors in the younger (12–15) age group (p < 0.05) along with parental cohabitation (p < 0.1). According to Exp(B), we can consider that girls have a 1.823 times higher chance of performing Physical SH and with a slight tolerance for Alpha and adolescents from an incomplete family (absence of one parent in the family environment) also have a 1.7 times higher chance of Physical SH than one from a complete family (parents living together). This is in contrast to the fact that in the second regression model with the older age group (16–18), neither sex nor parental cohabitation (p > 0.05), but only depressivity was found to be significant. Depressivity has a significant impact on Physical SH in both age subgroups (p < 0.001), and the strength of the impact is similar (in the 12–15 age group: Exp(B) = 1.199, while in the 16–18 age group: Exp(B) = 1.131). To sum up, we can interpret that higher levels of depression slightly increase the chance of physical self-harm in both age groups. In Table 4, we can also find model summary values explaining 35–45% in the younger age group (12–15) and 19–25% of the variability of Physical SH occurrence in the older age group (16–18).

Table 4. Binary logistic regression, performed separately for two age cohorts.

Age Group	Predictors	B	S.E.	Wald	Exp(B)	χ2	R2
12–15 yrs old	Depressivity	0.182 **	0.019	95.873	1.199	187.7 **	0.334–0.451
	Parental cohabitation (1)	0.508 a	0.272	3.492	1.662
	Sex (1)	0.617 *	0.242	6.47	1.853
	Constant	−3.487 **	0.327	113.419	0.031
16–18 yrs old	Depressivity	0.123 **	0.015	69.178	1.131	94.2 **	0.186–0.253
	Parental cohabitation (1)	0.229	0.24	0.914	1.258
	Sex (1)	−0.088	0.249	0.126	0.916
	Constant	−2.348 **	0.302	60.439	0.096

Notes: Predictors: Depressivity, parental cohabitation, sex. Dependent: Physical SH; parental cohabitation category coding: 0—parents living together, 1—parents living separately. Sex category coding: 0—boys, 1—girls; ^a p < 0.1, * p < 0.01, ** p < 0.001.

4. Discussion

Research into the phenomenon of self-harm has generally focused on revealing determinants, some of which appear to be protective and some higher risk. It is important to stress that all these factors manifest in the experience and behaviour of an individual, in the context of their personality; therefore, they acquire their meaning from a specific context. With respect to this, it is not possible to clearly determine those factors that trigger self-harming behaviour, but it is necessary to search for the risk potential of individual factors within the interaction between several factors. Nevertheless, it is possible to determine an essential aspect of self-harming behaviour, negative affectivity. From the viewpoint of negative emotions, in our study, bad mood as a symptom of depression in younger adolescents supports earlier findings that tension-increasing conflicts can contribute to the development of high-risk behaviour [1,49].

The prevalence of Physical SH in the younger age group (12–15) of 35.7% and 30.1% in the group of older adolescents (16–18) are in line with research findings from other contemporary research studies [4,11,19,50]. Furthermore, the above-mentioned studies confirm that physical SH is the most frequent among children aged 11–16 years, whereas self-harm cannot be excluded even in the younger or older age groups.

The results of this study are partially in line with current findings concerning the most common forms of Physical SH, namely scratching, and hitting [1,2]. Cutting is also among the most commonly found (physical) forms of self-harm (reported by about a quarter of respondents with Physical SH). Matsumoto et al. [12,35] state that such destructive behaviour may be understood as an effort to regain contact with oneself. The physical form burning is the least common in this set. Empirical studies [4,50] confirm hitting and cutting as one of the most common forms of physical SH among adolescents. This behaviour associates with the need to achieve immediate relief from psychological tension and is therefore considered a maladaptive strategy of emotional regulation. Burning, on the other hand, occurs less frequently but tends to relate to higher levels of dissociation, depression, or persistent affective tension [29,33,35]. Consequently, the functional significance of the behaviour should be emphasised—namely, the way in which different forms fulfil the need to regulate negative affect and manage psychological pain.

Following on from negative affectivity, we can interpret the results on the effect of depression as an individual factor on self-harm. The identification of significant connections between Physical SH and depressive symptomatology are in line with existing empirical studies ([51,52,53,54], etc.) and experts generally agree with the emphasis on emotional and social relationships [25,33,55,56,57,58]. In a broader context, we might interpret that the confrontation with everyday situations that can generate negative emotions is a universal constant. However, whether depressive episodes deepen, internalise, create depressive symptomatology, or merely create the potential for the emergence of depressive symptomatology (in the event that a provoking trigger occurs) is influenced by individual and specific factors (moderating, mediating). This opinion is supported by many experts ([1,10,26,31,59,60,61,62,63], etc.).

Another risk factor that was assessed as high-risk during the evaluation was the absence of a parent. We may assume that the absence of a parent in the family environment is one of the causes of emotional issues or anxiety that determine the symptomatic depressive episodes [24,51,52]. It is noteworthy that when evaluated separately, this factor has an effect on Physical SH in both groups, but within the regression model, it is insignificant in interaction with depression in late adolescence. A stronger independent effect of the absence of a parent can be observed in the 12–15 age group which is in line with the starting points [7,16]. The function of a family system is related to the perceived parental legacy. It directly or indirectly affects the development of somatic symptomatology, and it also relates to the tendency of the adolescent to self-harm. Parents who are separated is an indication of a disruption of the family system and leads to perception of parental discordance in various areas of their cohabitation. As stated by Brage et al. [26], an adolescent constantly longs for the biological parent to return. We assume that while the adolescent–parent relationship is stronger in early adolescence, older adolescents form more intense emotional bonds with peers and partners [18,64]. As the hormonal changes in early adolescence stabilise, the individual adapts to their role and relationships outside the family gain greater importance.

Based on the results of the study, we are able to state the strength of the predictors; more specifically, in early adolescence, female gender and an incomplete family are important determinants that have an individual effect on Physical SH. In the group of older adolescents (in middle and late adolescence), these predictors are depressivity and an incomplete family, but gender has no particular risk potential. In most gender (sex) comparative studies ([4,61,65,66,67,68], etc.) female gender has been identified as a risk factor for the development of self-harming behaviour. Some studies found that girls tend to experience problems more intensely through internalisation, e.g., reduced self-esteem [9,16]. This study found that the female subjects are twice as likely to develop Physical SH than boys, in the group of younger adolescents. This might be the result of feelings of greater vulnerability or, at the same time, a sign of a pubertal change (hormonal changes), as well as a sign of a lack of experience of self-expression in the social context of their emotional world (connection with family relationships). Girls experience emotions more intensely, and when they face problems, their risk of increased depressivity or a stronger need for social connection may rise.

Within the last objective, the above-mentioned factors together with the individual effects were included in a regression model, while confirming depressivity as a dominant risk factor and female gender being a risk factor in the younger age group (12–15). As Caspi and Moffitt [69] stated, when considering the development of emotional issues, it is important to consider how adolescents cope with growing up. It is individually linked to the personality of the adolescent and how they cope; during puberty, the characteristic features of an inability to function correctly are strengthened, primarily in girls who have faced difficulties since childhood.

In this context, Ge et al. [22] emphasised the individual history of the development of an adolescent. We might interpret that the selected factors of Physical SH in the study—depressivity, gender, and the absence of a parent in the family environment—have the potential to lead to high-risk developments. However, the regression model explains the influence of the determinants for 33–45% of the group of younger adolescents and for only 19–25% of the group of older adolescents. It may be stated that besides the predictors we examined, many other factors, that were not researched in this study contribute to the development of Physical SH. In early adolescence, intrapsychic and family factors such as depressive symptoms, emotional regulation, attachment, and the quality of the parent–child relationship play a significant role [11,29,34]. During this period, the family environment remains essential for shaping self-concept and coping strategies. In contrast, during late adolescence, contextual, and social factors become more prominent [33,51,54]. Self-harming behaviour in this stage is more closely linked to problems with social integration, peer pressure, or maladaptive stress-coping strategies than to intrapsychic factors. This suggests that individual predispositions (e.g., depression) may play a smaller, though still relevant, role with increasing age, while the social environment gains importance as both a trigger and maintaining factor of self-harm.

In late adolescence, contextual and social factors become more influential [23,67]. Their omission may have contributed to the lower explained variability and suggests that the determinants of self-harm change with age, with social factors—especially peer influence—playing a greater role [17,54,63]. Future research should therefore aim to extend the model to include social and behavioural factors that more accurately reflect the developmental characteristics of late adolescence [70]. In summary, the main predictors in this study—depression, gender, and parental cohabitation—represent family and individual factors that, according to the literature, play a crucial role particularly in early adolescence, when the family serves as the primary source of emotional support and regulation [11,29,34]. In late adolescence, however, peer and social relationships become increasingly important. This developmental shift in the determinants of physical self-harm is supported by Mičková [71], who notes that family bonds and emotional regulation are key in early adolescence, while peer and social processes play a greater role in late adolescence.

Limitations and Future Research

When interpreting the results, several methodological limitations should be considered. These constraints may affect the generalisability and precision of the findings and should be taken into account when drawing conclusions or planning future research.

The observed relationships cannot be interpreted as evidence that depression, gender, or parental cohabitation cause Physical SH, but only as factors associated with depressive symptomatology. Confirming causal or prognostic directions would require a longitudinal or experimental design; thus, the results should be viewed as correlational, considering other determinants of physical SH.

How problematic it may seem to omit a group with an isolated occurrence of self-harm. Adolescents reporting only rare or isolated self-harm were excluded to focus on recurrent and stable forms of behaviour (SH), in line with recommendations suggesting that single or experimental episodes represent a heterogeneous group with differing motivations and clinical relevance [29,51,54]. Occasional self-harm may reflect experimental risk-taking or short-term coping rather than stable dysregulation, though some experts view it as a subclinical phase of SH development [29,54]. In this context, it would be useful to include indirect or psychological forms of self-harming behaviour (according to Sansone and Sansone [46]) in the examination of the issue.

Another limitation involves the operationalisation of parental cohabitation as “parents living together” versus “apart,” reducing the concept of parental absence to formal separation. Excluding adolescents in other situations (e.g., parental death, reconstituted families) likely decreased variability and slightly influenced the effects of family environment. Consequently, the observed relationship between parental cohabitation and physical SH should be interpreted cautiously and verified with attention to family quality.

Within the limits, it is necessary to mention the questionable degree of generalisation. Despite the sample to the extent that generalisation is already possible (despite the convenient type of sampling), with self-assessment methods of data collection and an intimate topic, such as self-harm, we must always count on possible bias on the part of the respondents.

5. Conclusions

This study demonstrated that the most common form of Physical SH is scratching and, on the contrary, burning is the least common. A comparison of the effects of selected factors on the occurrence of Physical SH in two age groups (12–15 and 16–18) showed the following risk factors with individual effects: sex (girls) in the group of early adolescents and, in both age groups, the absence of a parent in the family environment and a higher degree of depressive symptomatology. However, among the younger age group, the regression analysis indicates that girls and individuals reporting higher depressive symptomatology have a greater risk of SH. The regression model showed that the absence of a parent, or parents living separately, was not significant for the older age group. Despite the configuration discovered for the risk predictors, other specific factors contribute to Physical SH. These findings increase interest in discovering and analysing other specific factors in order to create a multifactorial picture of the issue of self-harm in a broader sense.

The results suggest that Physical SH may be a manifestation of unnoticed problems (personality, family, social), with different quality or emphasis depending on the period of early and late adolescence. Professionals working with youth (including teachers, social workers, psychologists, and extracurricular leaders) should monitor self-harm and other risky behaviors, especially during the sensitive transition to adolescence, as changes in these behaviors may indicate unmet developmental needs.