Factors associated with chronic depressive symptoms across adolescence and young adulthood: a UK birth cohort study.

AIMS: Identifying children and/or adolescents who are at highest risk for developing chronic depression is of utmost importance, so that we can develop more effective and targeted interventions to attenuate the risk trajectory of depression. To address this, the objective of this study was to identify young people with persistent depressive symptoms across adolescence and young adulthood and examine the prospective associations between factors and persistent depressive symptoms in young people. METHODS: We used data from 6711 participants in the Avon Longitudinal Study of Parents and Children. Depressive symptoms were assessed at 12.5, 13.5, 16, 17.5, 21 and 22 years with the Short Mood and Feelings Questionnaire, and we further examined the influence of multiple biological, psychological and social factors in explaining chronic depressive symptoms. RESULTS: Using latent class growth analysis, we identified four trajectories of depressive symptoms: persistent high, persistent low, persistent moderate and increasing high. After applying several logistic regression models, we found that loneliness and feeling less connected at school were the most relevant factors for chronic course of depressive symptoms. CONCLUSIONS: Our findings contribute with the identification of those children who are at highest risk for developing chronic depressive symptoms.

Differences in clinical and cognitive variables in seasonal affective disorder compared to depressive-related disorders: Evidence from a population-based study in Finland.

BACKGROUND: Seasonal affective disorder (SAD) is a type of depression with seasonal pattern. Although it involves some idiosyncratic symptoms, it can overlap with other depressive disorders such as major depressive disorder (MDD) or dysthymia. We aimed to characterize the differences in specific cognitive and clinical symptoms between SAD and depressive-related disorders. METHODS: In total, 4554 Finnish subjects from the population-based Health 2011 Survey were interviewed with the Munich version of Composite International Diagnostic Interview (M-CIDI) and filled in the Seasonal Pattern Assessment Questionnaire (SPAQ). From this sample for our analysis, we included those participants who fulfilled the criteria for SAD (n=171), MDD (n=153) or dysthymia (n=84) and their 816 psychologically healthy controls matched by age and gender. In addition to M-CIDI and SPAQ, the Beck Depression Inventory, the General Health Questionnaire, an abbreviated version of the Mini-Mental State Examination, the category verbal fluency test, and the CERAD 10-word list were used. RESULTS: Subjects with dysthymia showed major deficits in both clinical and cognitive domains compared to MDD, SAD and healthy controls. Although clinical comorbidity was mild in SAD, these participants showed similar cognitive deficits to dysthymic subjects and greater impairments than MDD. CONCLUSIONS: SAD subjects show a differential clinical and cognitive profile compared to other depressive-related disorders. Although less severe clinical symptoms are found in these individuals, some cognitive impairment already appears in subjects with SAD recruited from a population-based study.