This review, conducted by a task force commissioned by the American Academy of Sleep Medicine, updates the evidence on the efficacy of psychological and behavioral treatments for insomnia from 1998 to 2004. The study included 37 treatment studies with a total of 2246 participants, focusing on both primary insomnia and insomnia associated with medical or psychiatric disorders. Key findings include: 1. **Efficacy of Treatments**: Psychological and behavioral therapies, including stimulus control therapy, relaxation, paradoxical intention, sleep restriction, and cognitive-behavior therapy (CBT), were effective in improving sleep parameters such as sleep onset latency, number and duration of awakenings, total sleep time, sleep efficiency, and sleep quality. 2. **Durability of Effects**: Sleep improvements were well sustained over time, with some studies showing long-term benefits. 3. **Generalizability**: The benefits of these treatments were observed in older adults and those with comorbid medical or psychiatric conditions, challenging the traditional notion that insomnia-specific treatment is less effective in these populations. 4. **Combination of Treatments**: There is a trend towards combining multiple treatments, with CBT being the most commonly used multi-component approach. 5. **Clinical Significance**: Limited evidence of clinically meaningful changes beyond reduced insomnia symptoms, such as improved daytime functioning and quality of life. 6. **Implementation**: Various implementation models, including individual, group, and self-help approaches, were effective, with some studies showing equivalent outcomes between different formats. 7. **Future Research**: Further research is needed to optimize outcomes, reduce morbidity, and validate treatments in clinical settings. Dissemination of evidence-based interventions to healthcare practitioners is also emphasized. The review concludes that psychological and behavioral interventions are effective for managing persistent insomnia, but more research is needed to understand the specific mechanisms and to develop more potent interventions.This review, conducted by a task force commissioned by the American Academy of Sleep Medicine, updates the evidence on the efficacy of psychological and behavioral treatments for insomnia from 1998 to 2004. The study included 37 treatment studies with a total of 2246 participants, focusing on both primary insomnia and insomnia associated with medical or psychiatric disorders. Key findings include: 1. **Efficacy of Treatments**: Psychological and behavioral therapies, including stimulus control therapy, relaxation, paradoxical intention, sleep restriction, and cognitive-behavior therapy (CBT), were effective in improving sleep parameters such as sleep onset latency, number and duration of awakenings, total sleep time, sleep efficiency, and sleep quality. 2. **Durability of Effects**: Sleep improvements were well sustained over time, with some studies showing long-term benefits. 3. **Generalizability**: The benefits of these treatments were observed in older adults and those with comorbid medical or psychiatric conditions, challenging the traditional notion that insomnia-specific treatment is less effective in these populations. 4. **Combination of Treatments**: There is a trend towards combining multiple treatments, with CBT being the most commonly used multi-component approach. 5. **Clinical Significance**: Limited evidence of clinically meaningful changes beyond reduced insomnia symptoms, such as improved daytime functioning and quality of life. 6. **Implementation**: Various implementation models, including individual, group, and self-help approaches, were effective, with some studies showing equivalent outcomes between different formats. 7. **Future Research**: Further research is needed to optimize outcomes, reduce morbidity, and validate treatments in clinical settings. Dissemination of evidence-based interventions to healthcare practitioners is also emphasized. The review concludes that psychological and behavioral interventions are effective for managing persistent insomnia, but more research is needed to understand the specific mechanisms and to develop more potent interventions.