This review updates the evidence on the effectiveness of psychological and behavioral treatments for persistent insomnia from 1998 to 2004. It summarizes findings from 37 studies involving 2246 participants, showing that psychological and behavioral therapies reliably improve sleep parameters in individuals with primary insomnia. These therapies include stimulus control, relaxation, paradoxical intention, sleep restriction, and cognitive-behavioral therapy (CBT). The review also highlights that these treatments are effective for insomnia associated with medical and psychiatric disorders, and for older adults. Treatment benefits are well sustained over time, with some studies showing long-term improvements. CBT was found to be particularly effective, with improvements in sleep onset latency, sleep efficiency, and other sleep parameters. The review also notes that psychological treatments are more effective than medication in some cases, and that CBT is more effective than relaxation alone. The review emphasizes the need for further research to develop more effective treatments and to better understand the mechanisms behind the effectiveness of these interventions. It also highlights the importance of disseminating the available evidence to healthcare providers to ensure its widespread use.This review updates the evidence on the effectiveness of psychological and behavioral treatments for persistent insomnia from 1998 to 2004. It summarizes findings from 37 studies involving 2246 participants, showing that psychological and behavioral therapies reliably improve sleep parameters in individuals with primary insomnia. These therapies include stimulus control, relaxation, paradoxical intention, sleep restriction, and cognitive-behavioral therapy (CBT). The review also highlights that these treatments are effective for insomnia associated with medical and psychiatric disorders, and for older adults. Treatment benefits are well sustained over time, with some studies showing long-term improvements. CBT was found to be particularly effective, with improvements in sleep onset latency, sleep efficiency, and other sleep parameters. The review also notes that psychological treatments are more effective than medication in some cases, and that CBT is more effective than relaxation alone. The review emphasizes the need for further research to develop more effective treatments and to better understand the mechanisms behind the effectiveness of these interventions. It also highlights the importance of disseminating the available evidence to healthcare providers to ensure its widespread use.