A random intercept cross-lagged panel analysis of the relationships between substance use, depressive symptoms, and...

Although the association among substance use, depressive symptoms, and suicidal behavior has been investigated, the longitudinal bidirectional relation remains poorly understood, particularly with respect to distinguishing between-person and within-person effects, this study aimed to investigate the within-person longitudinal relationships between substance use, depressive symptoms, and suicidal behavior.

This study used a longitudinal design to explore these associations among 5608 college students from two universities in a city in southern China (aged 17-22 years; M_age = 18.63 years, SD = 0.89; 48.2% females). Substance use was assessed using the Substance Use Questionnaire, depressive symptoms were measured with the 9-item Patient Health Questionnaire (PHQ-9), and suicidal behaviors were assessed using the Suicide Behavior Questionnaire-Revised (SBQ-R). The participants were assessed five times in a six-month interval over three years. Random intercept cross-lagged panel models (RI-CLPMs) were used to examine the within-person longitudinal relationships between substance use, depressive symptoms, and suicidal behavior.

The results of RI-CLPMs indicated that at the within-person level, suicidal behavior can positively predict subsequent depressive symptoms and substance use, significantly positively predicted subsequent depressive symptoms among females, but not substance use.

These results indicate that it is crucial to identify and address suicidal behavior among college students, as it can help prevent subsequent substance use and depressive symptoms.