Biological and clinical predictors of response in recurrent depression: a preliminary report.

Electroencephalographic (EEG) sleep and selected hormone measurements were investigated in a group of 34 recurrent depressives receiving both pharmacotherapy and psychotherapy. These biological variables were examined to determine whether such measures could predict the rapidity of treatment response. While the EEG measures of sleep onset difficulty and degree of rapid eye movement (REM) density provided some level of discrimination, the serum cortisol measure, particularly the cortisol nadir, significantly discriminated between normal responders and slow or nonresponders. These data support the notion that biological factors measured before treatment might relate to the rapidity and extent of clinical response achieved by the patient.