Behavioural measurement and drug response characteristics of unipolar and bipolar depression.

This research is part of the NIMH--CRB Collaborative Study on the psychobiology of depression. The main objective of the research programme is to test hypotheses concerning the interaction of neurobiological mechanisms and behaviour in the depressive disorders. Part I of the report describes the rationale and the overall approach to measuring behavioural state and outcome in the research programme. Part II reports on the results of applying the behavioural methods to a comparison of the clinical phenomenology of unipolar and bipolar depression. The behavioural patterns expressed during the episode by the two groups are different. Further, the two types are shown to react differently to treatment with tricyclic drugs, reinforcing the thesis that they are qualitatively distinct forms of the depressive disorders.