Childhood trauma is a risk factor for suicidal ideation in patients with depressive disorder, and plasma vitamin D level is also related to suicidal ideation. However, there is still insufficient research on the relationship between them in adolescent patients with depressive disorder.

To explore the relationship between suicidal ideation and childhood trauma and to analyze the mediating role of depressive symptom severity and low vitamin D levels.

Adolescent patients with depressive disorder who attended Chaohu Hospital of Anhui Medical University and the Fourth People's Hospital of Hefei City in 2021 were used as the depressive disorder group (n=168), and adolescents with no history of mental illness recruited during the same period were used as the control group (n=89). Childhood trauma, depressive symptoms, and suicidal ideation were assessed using the Childhood Abuse Questionnaire (CTQ), the Current Evaluation of Depression Scale (CES-D), and the Suicidal Ideation Scale (PANSI), and plasma 25-hydroxyvitamin D[25 (OH) D] levels were also tested. Differences between adolescents with depressive disorders and control adolescents in suicidal ideation, depressive symptoms, childhood trauma, and vitamin D levels were compared; Pearson correlation analyses were used to test the correlation of scores on each scale, and the mediating roles of depression and vitamin D levels between childhood trauma and suicidal ideation were analyzed by the PROCESS macro program.

Adolescents in the depressive disorder group had higher PANSI scores, CTQ subscale scores, and total scores than those in the control group (P<0.05), and lower 25 (OH) D levels than those in the control group (P<0.5). Pearson correlation analyses showed that there were correlations between the PANSI scores and the CTQ total scores, the CES-D scores, and the 25 (OH) D levels of adolescents in the depressive disorder group (P< 0.05), and the PANSI scores of adolescents in the control group were correlated with total CTQ scores, CES-D scores (P<0.05), and no correlation with 25 (OH) D levels (P>0.05). The mediation benefit analysis showed that the CES-D score and 25 (OH) D level in the adolescent group with depressive disorder played a partial mediating role between the CTQ total score and PANSI score, with mediation effects accounting for 61.8% and 5.3%, respectively; and a partial mediating role between the CTQ affective abuse subscale score and PANSI score, with mediation effects accounting for 58.9% and 6.5%; a partial mediating role between CTQ emotional neglect subscale scores and PANSI scores, with mediating effect percentages of 67.2% and 5.6%, respectively; and a full mediating role between CTQ somatic neglect subscale scores and PANSI scores, with mediating effect percentages of 92.2% and 7.8%. None of the mediating effects of 25 (OH) D levels were significant for control adolescents; CES-D scores played a fully mediating role between CTQ total scores and PANSI scores, and between CTQ emotional maltreatment subscale scores and PANSI scores; and a partially mediating role between CTQ emotional maltreatment subscale scores and PANSI scores, with a direct effect percentage of 41.5% and a mediating effect accounted for 58.5%; the mediating effect between CTQ somatic neglect subscale scores and PANSI scores was not significant.

The severity of depressive symptoms and low vitamin D levels in patients with adolescent depressive disorder are potential mechanisms of childhood trauma leading to suicidal ideation. In view of the disorder of childhood trauma of adolescent depression in clinical should be timely and effective control and improvement of patient, improve their vitamin D levels and actively carry out mental health education, in order to reduce the occurrence of suicidal ideation, improve clinical outcomes.