The socioeconomic impact of major depression is considerable, due to poor patient functioning and increased social impairment, bed disability days, and use of health care resources. Major depression and the side effects of antidepressants medication also adversely affect patients' quality of life (QOL). However, few clinical trials of major depression examine QOL as a measure of treatment outcome. A comprehensive, quantitative QOL instrument for depression was recently tested and validated as conforming to accepted psychometric standards. The sertraline quality of life battery (SQOLB) consists of nine domains measuring health perceptions: energy/vitality, cognitive function, social interaction, alertness behavior, work behavior, home management, life satisfaction, and bed disability days. The SQOLB has been used in two open-label trials of sertraline. In the first study, the SQOLB was administered to 400 patients with major depression at baseline and final visit in a 6 week, open-label, general practice study. At endpoint, mean Montgomery-Asberg Depression Rating Scale (MADRS) and Clinical Global Impression (CGI) scores were significantly improved. The QOL battery also showed significant (p < 0.001) positive changes from baseline to final visit in all nine domains measured. In the second study, the SQOLB was used as part of an 8 week, open-label trial of sertraline in 308 UK hospital outpatients being treated for depression by psychiatrists. Sertraline was effective in managing the depression and caused statistically significant improvements (p < 0.001) in all QOL domains measured. The QOL scales give a better indication of the effect of pervasive depressive symptoms on a patient's life than rating scales of depressive symptomatology.(ABSTRACT TRUNCATED AT 250 WORDS)