A study was conducted to examine sex differences in frequency, duration and severity of experience of depressed mood state in a non-clinical group and to consider how such findings contribute to the understanding of sex differences in depressive experience. A cohort of 156 subjects, assessed initially in 1978 in their last year of teacher training, was reassessed at 5-yearly intervals over 15 years. On each occasion, the subjects completed self-report ratings of experience of "normal depression" and measures of neuroticism, trait depression, self-esteem and sex role. The study found no sex differences in the number or duration of episodes. Women reported more symptoms per episode and some specific symptoms (including tearfulness, appetite and weight gain) more often. The number of symptoms was correlated with neuroticism, self-esteem and trait depression scores, and with gender but not sex role. The number of episodes was related to trait depression and self-esteem but not neuroticism. The results showed that there are links between female gender, neuroticism and number of symptoms experienced during depressed mood state episodes. These links are related more to female gender than to feminine sex role or premenstrual problems, and are reflected in the severity of affective change (and some specific symptoms) but not in the number of episodes.