BACKGROUND AND PURPOSE: To evaluate the effects of trazodone on subjective and objective measures of sleep in depressed insomnia patients treated with selective serotonin reuptake inhibitors (SSRIs). SSRIs can exacerbate or cause new insomnia while alleviating other symptoms of depression. Trazodone has been reported to be an effective hypnotic for patients with antidepressant-associated insomnia. PATIENTS AND METHODS: Twelve female patients were given either 100 mg trazodone or placebo for 7 days in a double-blind crossover design with a 7-day washout period. Polysomnographic recordings were repeated on the 3rd, 9th and 17th, 23rd nights after treatment with trazodone or placebo. Sleep was assessed by Pittsburgh sleep quality index (PSQI) at the beginning and end of the study. Psychological evaluation was done by Hamilton depression rating scale (HDRS). RESULTS: Trazodone significantly increased total sleep time, percentage of stages 3+4, sleep efficiency index, sleep continuity index and decreased percentage of stage 1, number of awakenings, stage shifts compared to the baseline. This improvement was also obtained after 7 days of treatment. The PSQI score was reduced to 5+/-1.6 at the end of the study. HDRS was reduced to 11.5+/-4.5 with trazodone and to 12.2+/-3 with placebo. CONCLUSION: Trazodone is effective in the treatment of antidepressant-associated insomnia.