Risk factors in unipolar depression: II. Relation between proband REM latency and cognitions of relatives.

In an ongoing study of risk factors for depression in first-degree relatives of unipolar depressed probands, we have assessed cognitive variables (beliefs, attributional style, and moment-to-moment thinking) in relatives of reduced REM (rapid eye movement) latency unipolar probands, nonreduced REM latency unipolar probands, and normal control probands. Relatives of reduced REM latency probands had more negative cognitions; the effect of REM latency of the proband was independent of the effect of a personal history of depression in the relative. It appears that both biological and psychological factors can be identified as predictors for lifetime rates of depression and may be useful in identifying high-risk individuals.