Depression and clinical high-risk states: Baseline presentation of depressed vs. non-depressed participants in the NAPLS-2 cohort.

Depressed mood appears to be highly prevalent in clinical high risk (CHR) samples. However, many prior CHR studies utilize modest size samples and do not report on the specific impact of depression on CHR symptoms. The aim of the current paper is to investigate the prevalence of depressive disorders and the impact of lifetime depression on baseline clinical presentation and longitudinal outcomes in a large cohort of individuals meeting CHR criteria in the second phase of the North American Prodrome Longitudinal Study (NAPLS-2). Depression was assessed both categorically (via DSM-IV-TR diagnoses) and symptomatically (using a clinician-rated scale of depressive symptoms) within a sample of 764 individuals at CHR and 279 controls. Current and lifetime depressive disorders were highly prevalent (60%) in this sample. Depression diagnoses were associated with more pronounced negative and general symptoms; individuals with remitted depression had significantly less severe negative, disorganized, and general symptoms and better social and role functioning relative to those with current depression. Current mood disturbance, as measured by scores on a clinician-rated symptom scale, contributed beyond the impact of positive and negative symptoms to impairments in social functioning. Both symptomatic and diagnostic baseline depression was significantly associated with decreased likelihood of remission from CHR status; however depression did not differentially distinguish persistent CHR status from transition to psychosis at follow-up. These findings suggest that depressed mood may function as a marker of poor prognosis in CHR, yet effective treatment of depression within this population can yield improvements in symptoms and functioning.