To evaluate if Internet delivered cognitive behavior therapy is an efficacious treatment when compared to a control group consisting of supportive therapy.

Inclusion Criteria:

• outpatient
• ≥ 18 years
• primary diagnosis of BDD according to the DSM-5
• BDD-YBOCS ≥20
• regular access to a computer with Internet access and skills to use the web.

Exclusion Criteria:

• psychotropic medication changes within two months prior to the treatment,
• completed CBT for BDD within the last 12 months,
• other primary axis I diagnosis
• current substance dependence
• lifetime bipolar disorder or psychosis
• suicidal ideation
• Axis II diagnosis that could jeopardize treatment participation,
• other current psychological treatment that could affect BDD symptoms
• A serious medical illness that precludes participation in the study