Mood Symptoms and Impairment Due to Substance Use: A Network Perspective on Comorbidity
Background: Mood disorders and problematic substance use are highly comorbid and confer reciprocal risk for each other. Despite theories that posit that specific features of one disorder pose risk for the other, there is a dearth of studies utilizing complementary analytic approaches, such as network analysis. Methods: A sample of 445 participants (59.8% female, Mage = 20.3 years) completed measures of depression and hypo/mania symptoms and substance use-related impairment. Results: Impulsive and interpersonal impairment were the domains of impairment most highly co-occurring with mood symptoms. Suicidal ideation, sadness, decreased need for sleep, and guilt were the mood symptoms most highly co-occurring with substance use-related impairment. Cross-lagged panel network models found that interpersonal impairment due to substance use was the strongest cross-construct predictor of mood symptoms and that suicidal ideation and guilt were the mood symptoms most predictive of substance-related impairment. Social, intrapersonal, and physical impairment due to substance use were the domains most predicted by previous mood symptoms and decreased need for sleep, guilt, and euphoria were the most strongly predicted by past substance use-related impairment. Limitations: Measures do not assess all mood symptoms, participants with low reward sensitivity were excluded, self-report measures, some variables were single-items. Conclusions: Results suggest that components of these syndromes that confer future risk for the other might not be the same components that are predicted by the other, highlighting that the bidirectional relationship between mood symptoms and problematic substance use might be better conceptualized at the element, rather than diagnostic, level.