The longitudinal relationship of alcohol problems and depressive symptoms and the impact of externalising symptoms: findings from the Belfast Youth Developmental Study.

PURPOSE: The aim of the present study was to contribute to the inconsistent literature on the comorbid relationship of alcohol problems and depressive symptoms from late adolescent to emerging adulthood by accounting for their trajectories and their conjoint relationship while controlling for the influence of externalising symptoms. METHODS: We utilised data, from a longitudinal school cohort from Northern Ireland (Belfast Youth Developmental Study), over three time points where the participants were 16, 17 and 21 years of age. A total of 3118 participants were included, 1713 females and 1405 males. Second-order latent growth models were applied to examine growth trajectories. Parallel process growth models were used to assess whether growth trajectories of the symptoms were associated. Externalising symptoms were subsequently added as a covariate. RESULTS: Alcohol problems among males significantly increased over time but decreased in females. Depressive symptoms initially increased then decreased in both genders. Results indicated associations of the alcohol problems and depression, both initially and with time. Accounting for externalising symptoms only somewhat diminished this effect in males but not in females. An increase of initial levels of depression was associated with a decrease in alcohol problems over time. This association was only true among females. After controlling for externalising symptoms, the relationship was no longer observed. CONCLUSIONS: The present study provides further evidence of a significant relationship of alcohol problems and depression in adolescents and further supports a small literature indicating that depression may have protective effects of alcohol problems. Finally, the study shows the importance of accounting for externalising symptoms.

Gender and Direction of Effect of Alcohol Problems and Internalizing Symptoms in a Longitudinal Sample of College Students.

BACKGROUND: Alcohol problems and internalizing symptoms are consistently found to be associated but how they relate to each other is unclear. OBJECTIVE: The present study aimed to address limitations in the literature of comorbidity of alcohol problems and internalizing symptoms by investigating the direction of effect between the phenotypes and possible gender differences in college students. METHOD: We utilized data from a large longitudinal study of college students from the United States (N = 2607). Three waves of questionnaire-based data were collected over the first two years of college (in 2011-2013). Cross-lagged models were applied to examine the possible direction of effect of internalizing symptoms and alcohol problems. Possible effects of gender were investigated using multigroup modeling. RESULTS: There were significant correlations between alcohol problems and internalizing symptoms. A direction of effect was found between alcohol problems and internalizing symptoms but differed between genders. A unidirectional relationship varying with age was identified for males where alcohol problems initially predicted internalizing symptoms followed by internalizing symptoms predicting alcohol problems. For females, a unidirectional relationship existed wherein alcohol problems predicted internalizing symptoms. Conclusions/Importance: We conclude that the relationship between alcohol problems and internalizing symptoms is complex and differ between genders. In males, both phenotypes are predictive of each other, while in females the relationship is driven by alcohol problems. Importantly, our study examines a population-based sample, revealing that the observed relationships between alcohol problems and internalizing symptoms are not limited to individuals with clinically diagnosed mental health or substance use problems.