Insomnia often persists despite adequate pharmacotherapy in depression and represents an obstacle to its full remission. It is unclear whether psychotherapy targeted for insomnia can improve clinical outcomes for patients with residual depression and treatment refractory insomnia. We aimed to evaluate the added value of brief Behavioral Therapy for insomnia （bBTi）over treatment as usual（TAU）for residual depression and refractory insomnia.
 Randomized controlled trial in 37 adults with residual depression and refractory insomnia was conducted. Twenty patients received TAU plus bBTi, consisting of 4 weekly 1-hour individual sessions, administered by psychiatrists or nurses. The rest received TAU alone. The Insomnia Severity Index（ISI）scores at 8 weeks were defined as the primary outcome. The Hamilton Rating Scale for Depression（HAMD）scores assessed by blind raters, and remission rates for both insomnia and depression were also evaluated. Analysis of covariance was used to test group effects while controlling for the baseline scores. The protocol was approved by the Ethics Committees of all the recruiting centers. Written informed consent was obtained from all participants.
 The bBTi plus TAU resulted in significantly lower ISI scores than TAU alone at 8 weeks （P＜.0005）. Significant differences were observed in favor of the combination group for both on the total HAMD scores（P＝.013）and on the HAMD scores after removing the three sleep items（P＝.008）. The combination treatment produced higher rates of remission than TAU alone,both in terms of insomnia（50%［10/20］vs.0%［0/17］）with a number-needed-to-treat （NNT）of 2（95% confidence intervals, 1 to 4）, and in terms of depression（50%［10/20］vs. 6%［1/17］）with an NNT of 2（1 to 5）.
 For the purpose of dissemination of bBTi,we are planning two additional trials taking account of the intensity of bBTi and of the effectiveness in a real-world situation.