An open study of the effectiveness of Internet treatment for panic disorder delivered in a psychiatric setting.

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.