How Impulsivity is Associated with Adolescent Depression: The Role of Substance Use, Gender and Social Support.

Background: Some risk/protective factors of adolescent depression have been proposed but have not been comprehensively studied. Recent advances in neuroimaging techniques have provided greater insight into the underlying neuropsychiatric mechanisms of depression-related factors such as impulsivity, substance use, gender difference and social support. However, how these factors are interconnected and how they affect depression in the real world is poorly understood. This study aimed to explore the relationships between adolescent depression with trait impulsivity, substance use and gender. We also tested the hypothesis that social support may play a buffering role in preventing depression. By expanding the diathesis-stress model. Methods: The adolescents enrolled in this study were grade 1 senior high school students from northern Taiwan (N = 5879), and they were assessed for depression, trait impulsivity, and tobacco/alcohol use. Hierarchical multiple linear regression was performed to control possible confounders, including other depression-related diathesis and sociodemographic variables. Gender differences were also analyzed by separately examining variables significantly associated with depression. Results: A higher level of depression was associated with female gender, trait impulsivity, low self-esteem, negative attitude towards the future, tobacco use, alcohol use, family discord and difficulty in basic family needs. Good parental health, living with their biological family and social support were protective factors. Trait impulsivity was significantly associated with depression after controlling for the confounding factors. Gender-specific analysis showed that trait impulsivity and tobacco use had a significant synergistic interaction on female depression. Social support from parents/peers was significantly associated with depression, but social support from other family members/teachers was not. Conclusion: The current study advances the understanding of adolescent depression and highlights that trait impulsivity, addictive substance use, social support and their interaction may play an influential role in the emergence of adolescent depression. Gender-specific research and treatment approach are also crucial, and more investigations are necessary.