The authors assessed the severity of nortriptyline side effects in older patients with major depression during 12 months of double-blind therapy. Data were from 40 patients completing 1 year of maintenance therapy: 26 were on nortriptyline and 14 were on placebo. The authors detected significant time-by-treatment interactions for various side effects (all greater in treated patients), but not for overall side effects score. Clinically, these differences were judged to be minor and correctable. On the other hand, total side effect scores, physical tiredness, and subjective sleep disturbance covaried significantly with Hamilton Depression scores regardless of treatment assignment. Somatic worry, tiredness, and sleep complaints appeared to reflect residual depression rather than treatment assignment.