['Cognitive behaviour therapy (CBT) of primary insomnia is frequently combined with various pharmacological treatments, including sedative antidepressants. The present study was undertaken to evaluate the clinical efficacy of CBT, singly and combined with trazodone pharmacotherapy, for primary insomnia.', 'Randomised, comparative clinical trial, at a single academic medical centre.', 'Twenty outpatients (15 women, 5 men) with chronic primary insomnia were randomly assigned to CBT or CBT +100mg trazodone and treated for 8 weeks. The treatment outcome was estimated by mean changes from baseline in self-reported clinical scales, sleep continuity data and sleep architecture parameters.', 'All patients perceived significant subjective sleep improvements. Sleep latency significantly shortened (p=0.03), sleep efficiency increased (p=0.004) and the total sleep time was significantly prolonged (p=0.006) after the CBT treatment in both groups. Sleep architecture showed that the combined approach (CBT + trazodone) resulted in a significant increase in slow wave sleep duration compared to treatment by CBT only (p=0.04).'] Does trazodone improve the results of cognitive behaviour therapy of primary insomnia in non-depressed patients?