Internet-based Exposure Therapy for Panic Disorder

The purpose of this study is examine if an internet-based exposure therapy based on inhibitory learning is feasible, acceptable and effective in reducing panic symptoms amongst patients who suffer from panic disorder and agoraphobia.

Trial objectives: Primary objective is to examine if an internet-based exposure therapy based on inhibitory learning is effective in reducing panic symptoms. The secondary objective is to study if the protocol is feasible and acceptable. Secondary objective is measured is examined on 1) number of participants completing the study protocol, 2) participants' satisfaction with the treatment, 3) therapists' ratings of acceptability. The aim of this study is to assess the feasibility, and pilot the design and delivery of a RCT that will subsequently form the framework for a larger RCT to evaluate the effectiveness of an exposure protocol based on inhibitory learning. Trial Design: Randomized controlled pilot study with two groups randomly assigned to either Internet-based exposure therapy based on the principles of inhibitory learning or Internet-based exposure therapy based on the principles of habituation Duration: Eight weeks Primary Endpoint: Change in panic symptoms from baseline to Week 8. Efficacy Parameters: Panic Disorder Severity Scale - Self rated (PDSS-SR) Safety Parameters: Adverse Events is assessed weekly via the internet. Description of Trial Subjects: Patients > 18 years old with a PDSS-SR score more than 6 points Number of Subjects: 80

The experimental group will go through Internet-based treatment. The exposure treatment is 8 weeks long and based on the principles of inhibitory learning, i.e. the participant is instructed to stay in the frightening situation until his/her expectancy has been maximally violated.

The active comparator group will also go through Internet-based treatment. The exposure treatment is 8 weeks long and based on the principles of emotional processing theory, i.e. the participant is instructed to stay in the frightening situation until anxiety has declined (habituated).

Internet-based cognitive-behavior therapy on a safe internet platform. Treatment is divided into eight modules, each containing homework assignments . The participants will be assigned a therapist that they can contact through a message system in the platform and expect answer within 24 hours.

Inclusion Criteria: Outpatients ≥ 18 years Situated in Sweden Informed consent Panic Disorder Severity Scale - self rated score more than 6 points Exclusion Criteria: Substance dependence during the last six months Post traumatic stress disorder, bipolar disorder or psychosis Symptoms better explained by axis 2 diagnosis (e.g. autism or borderline personality disorder) MADRS-S score above 25 points Psychotropic medication changes within one months prior to treatment that could affect target symptoms. Received exposure based Cognitive behavior therapy (CBT) for pathological worry the last 2 years