Brief-intensive CBT Versus Once-weekly CBT in Anxiety-related Disorders

The goal of this clinical trial is to compare brief-intensive cognitive-behaviour therapy (CBT) with regular weekly CBT in people with anxiety-related disorders.

The main question to answer is: will brief-intensive CBT improve functioning (work, family, social) more and faster than does regular weekly CBT?

Participants will be asked to follow CBT treatment (20 sessions of 45 minutes in both conditions), and participate in 7 measurements with a total duration of 5 hours over 1 year.

Researchers will compare:

* Brief-intensive CBT: 16 sessions in 2 weeks + 4 follow-up sessions within 3 months
* Regular CBT with 20 weekly sessions in 6 months

Rationale: Anxiety-related disorders (i.e., obsessive compulsive, health anxiety and trauma disorders) affect about 10% of the adults. Though clinically heterogeneous, transdiagnostic aspects are expected disasters, anxiety and avoidance. Profound impairments include work and family functioning. Many enter a vicious circle with comorbidity and further decline in quality of life. Hence, the impact on functioning is tremendous, with anxiety-related disorders rating highest on disability rankings in the age 15-64 years. Cognitive behavioral therapy (CBT) is the preferred and often only psychotherapy for these disorders. Because guidelines are based on weekly sessions, recovery takes half a year at least. Based on initial research findings, we expect faster recovery by providing CBT in a brief-intensive format (BI-CBT), with clear benefts for patients, families and society. Some institutions already provide BI-CBT. However, evidence to justify this or to further implement BI-CBT is insufficient.

Study design: a parallel-group randomised controlled multicenter intervention study.

Study population: Adults aged 18-65 yr old with an anxiety-related disorder (panic, agrophobia, social anxiety, generalised anxiety obsessions/compulsions, health anxiety and post-traumatic stress)

Intervention (if applicable): One group receives BI-CBT (16 sessions in 2 weeks + 4 follow up sessions) and the other group receives 20 weekly CBT sessions. Treatment in both conditions can be personalised by a focus on work or family functioning.

Main study parameters/endpoints: The main study parameter is the 'area under the curve' for 6-month health and disability. Also, 1 year efficacy (both on functioning and symptom-level), cost-effectiveness, and feasibility will be assessed. Potential predictors of treatment preference, efficacy and drop-out will be explored.

All patients are expected to follow CBT (20 sessions of 45min) and participate in 7 measurements over 1 year.

The general measurements are online questionnaires and interviews by telephone, asking about someones functioning, quality of life and symptoms of anxiety or depression, how one copes with these and what one expects of the therapy.

The acronym KOMMA is based on the Dutch translation of 'to put a quick end to anxiety': Korte Metten Met Angst.

Eligibility Criteria:
Inclusion Criteria:

Age 18 years or older;

Reaching out for mental health care for one of the following disorders:

panic disorder, agoraphobia, generalised anxiety disorder, social anxiety disorder, posttraumatic stress disorder, obsessive-compulsive disorder, health anxiety disorder.

Exclusion Criteria:

* Is in need of emergency mental health care
* Has insufficient language skills in Dutch
* Has evident cognitive limitations
* Has had changes in the use of medication during the last 3 months.