Is depression severity the sole cause of psychotic symptoms during an episode of unipolar major depression? A study both between and within subjects.

Background: Despite the common clinical assumption that psychosis is an indicator of severity in depression, it is not known what determines the presence of psychotic features in major depression. Our aim was to answer the question: Is depression severity the sole cause of psychotic symptoms during an episode of unipolar major depression?

Methods: In a sample of 585 patients from the UK, meeting criteria for both DSM-IV and ICD-10 major recurrent depression, we assessed measures of severity of depression and the presence of psychotic features, both within and between subjects.

Results: Within patients, psychotic episodes tended to be more severe than non-psychotic episodes.

Differences in depressive symptom profile between males and females.

Background: It is widely held that there are no differences in the symptom profile of male and female depression. Studies to date that have found differences have used different methodologies and had inconsistent findings. Here we compare the clinical profile of major depression for men and women from a sample of almost 600 well-characterized individuals with recurrent major depressive disorder (MDD).