Internet-based Treatment for Depression and Panic disorder : From development to deployment

Sammanfattning: Major depression (MD) and panic disorder (PD) are two common disorders for which evidence based psychological treatments such as cognitive behaviour therapy (CBT) have been developed. The accessibility of such treatment is however limited. The use of Internet-based CBT (self-help programmes accompanied by brief therapist support by e-mail) is a promising way to increase accessibility. The first aim of this thesis was to investigate if Internet treatment was effective in reducing depressive symptoms and if it was possible to predict which participants would benefit from such treatment. The second aim of the thesis was to investigate if Internet treatment was effective for PD patients in a regular care setting, in comparison with traditional group-administered CBT, and in addition, to compare the cost-effectiveness of the two treatments. In Study I 85 participants were randomised to either an Internet treatment or to an attention control condition (an online discussion group). Post-treatment measures of depression showed large effect sizes and improvements were sustained at a 6-month follow-up, thus showing that Internet treatment was effective in reducing mild to moderate symptoms of depression. Study II analysed predictors of treatment outcome at the 6-month follow-up of Study I. Higher selfreported severity at baseline was associated with poorer outcome and a negative correlation was found between number of previous episodes of depression and improvement in treatment. Study III was an open effectiveness trial evaluating Internet treatment, which in previous studies had been shown to be effective with self-recruited participants, within a regular psychiatric setting for 20 PD patients referred for treatment. After treatment 75% of patients were considered to have responded to treatment, and at the 6-month follow-up this proportion was 70%, indicating that this treatment form was transferable to a regular care setting with sustained effectiveness. Study IV was a randomised clinical trial comparing Internet- and groupadministered CBT for PD with 104 patients in a psychiatric setting. Both treatments produced significant improvements, and there were no statistically significant differences between them at post-treatment or at the 6-month follow up. A cost-effectiveness analysis showed that the Internet treatment was more cost-effective than the group treatment with regard to therapist time. This thesis provides evidence that Internet treatment is effective in reducing symptoms of depression and of PD. Internet treatment is as effective as traditionally administered group CBT in a regular care setting with PD patients referred for treatment. The thesis also provides evidence that Internet treatment for PD is more cost-effective than group treatment. Taken together, the results support the implementation of Internet treatment for depression and PD within regular health care settings.