Measurement of subclinical changes during lithium prophylaxis: a longitudinal study.

Psychological distress was observer-rated with the Brief Psychiatric Rating Scale (BPRS) and self-rated with the Symptom Questionnaire (SQ) every other week for a 6-month period in 9 apparently remitted bipolar patients attending a lithium clinic. Substantial clinical fluctuations in psychopathology were observed with both rating methods. Compared to normal control subjects, patients suffering from bipolar disorder displayed significantly higher BPRS and SQ anxiety, somatization and total distress scores.