Abstract
Panic disorder with or without agoraphobia (PD/A) is common and can be treated effectively with selective serotonin reuptake inhibitor (SSRI) medication or cognitive–behaviour therapy (CBT). However, the lack of access to CBT services has motivated the development of self-help approaches requiring less therapist contact. A novel treatment modality in this field, showing efficacy in several randomized trials but until now not evaluated within the context of regular psychiatric care, is Internet-based treatment. The aim of the present study was to evaluate the effectiveness of Internet-based CBT for patients in a psychiatric setting. Twenty consecutively referred patients with PD were included in the study. A structured clinical interview with a psychiatrist was conducted for inclusion, as well as at post-treatment and at the 6-month follow-up. The treatment consisted of a 10-week CBT-based self-help programme, including minimal therapist support by e-mail. At post-treatment, 94% of patients no longer met DSM-IV criteria for PD (82% at 6-month follow-up). The within-group effect sizes (for the main outcome PDSS; Panic Disorder Severity Scale) were Cohen's d=2.5 (pre- to post-treatment) and 2.8 (pre-treatment to follow-up), respectively. The proportion of responders on the PDSS was 75% at post-treatment and 70% at 6-month follow-up. The results supports earlier efficacy data on Internet-based CBT for PD and indicates that it is effective also within a regular psychiatric setting. However, a larger randomized controlled trial should be conducted, directly comparing Internet-based CBT with traditionally administered CBT within such a setting.