Neurobiological Markers of Treatment Response for Anxiety and OCD

The primary study will include 500 OCD patients who will receive the B4DT. Symptom severity will be prospectively measured before treatment, approximately 10 days after treatment and three months after treatment. Saliva samples will be collected for later extraction of DNA methylation during the first day of treatment, the last day of treatment, and three months after treatment. A substudy will use multimodal magnetic resonance imaging (MRI) before treatment, approximately 10 days after treatment and three months after treatment. The substudy will also 100 patients with social anxiety disorder or panic disorder for DNA methylation and MRI, as well as 50 healthy controls for MRI. Clinical data will be collected from a consent-based quality register ("Kvalitetsregister for konsentrerte behandlingsformat").

The aim of the study is to investigate changes in DNA methylation as well as functional and structural brain networks that occur in patients undergoing B4DT, and to correlate these changes with immediate and long-term response to treatment.

Inclusion criteria

• Diagnosed with obsessive-compulsive disorder, panic disorder or social anxiety disorder using DSM-5 criteria
• Referred to National Clinic for 4-Day Treatment, Haukeland University Hospital, Bergen, Norway
• Consented to participate in the "Kvalitetsregister for konsentrerte behandlingsformat"

Exclusion criteria

• Suicidal, ongoing mania, primary eating disorder, intellectual disability, ongoing psychosis, ongoing substance abuse

For MRI substudy:

Inclusion criteria

• For the healthy controls, no previous or current psychiatric disorders as detected by the Mini International Neuropsychiatric Interview (MINI)

Exclusion criteria

• MRI incompatibility (e.g. pregnancy, metal implants)