Transdiagnostic Cognitive Behavior Therapy (CBT) delivered in the individual format, have been proven just as effective as traditional diagnosis specific CBT manuals. The investigators have translated and modified the "The Unified Protocol for Transdiagnostic Treatment of Emotional Disorders" (UP-CBT) to make it applicable as group therapy in Danish Mental Health Service and a naturalistic trial of this manual has shown promising results. As the use of one manual instead of several diagnosis specific manuals in regional clinics could simplify logistics and reduce waiting time, the investigators want to compare group UP-CBT with diagnosis specific group CBT.

Method: A partial blinded, pragmatic, non-inferiority, multicentre randomized clinical trial (RCT). UP-CBT is compared to treatment-as-usual CT. 124 patients are included in each intervention arm, recruited from three Danish regional Mental Health Service Clinics. 31st July 2018 suppl: Inclusion number expanded to 170 in each arm due to unexpected large drop-out.

Background: Transdiagnostic Cognitive Behavior Therapy (TCBT) Manuals delivered in individual format, have been reported to be just as effective as traditional diagnosis specific CBT manuals. The investigators have translated and modified the "The Unified Protocol for Transdiagnostic Treatment of Emotional Disorders" (UP-CBT) developed by Barlow and colleagues for use in Mental Health Service (MHS), and shown effects comparable to traditional CBT in a naturalistic trial. As the use of one manual instead of several diagnosis-specific manuals could simplify logistics, reduce waiting time, and increase therapist expertise compared to diagnosis specific CBT, the study aim to test the relative efficacy of group UP-CBT and diagnosis specific group CBT.

Methods/design: It is a partially blinded, pragmatic, non-inferiority, parallel, multi-center randomized controlled trial (RCT) of UP-CBT vs diagnosis specific CBT for depression, social anxiety disorder and agoraphobia/panic disorder. In both arms, the intervention consists of weekly group session for 14 weeks. In total, 248 patients are recruited from three regional MHS centers across the country and included in two intervention arms.31st July 2018 suppl: Inclusion number expanded to 340 due to unexpected large drop-out.

Outcomes are measured at end of therapy and at 6 months follow-up. Weekly patient-rated outcomes and group evaluations are collected for every session. Outcome assessors, blind to delivered intervention, will perform the observer-based symptom ratings, and fidelity assessors will monitor manual adherence.

Discussion: The current study will be the first RCT investigating the dissemination of the UP in a MHS setting and UP delivered in groups and including patients with depression. Hence the results are expected to add substantially to the evidence base for rational group psychotherapy in MHS. The planned moderator and mediator analyses could spur new hypotheses about mechanisms of change in psychotherapy and the association between patient characteristics and treatment effect.

Inclusion Criteria:

Referred to Danish Mental Health Service

1. a principal DSM-5 diagnosis of Unipolar Depression (single episode or recurrent)(app. 50%), Social Anxiety Disorder (app. 25%), and Agoraphobia/Panic Disorder (app 25%)
2. the patient is currently not using any antidepressants or use accepted antidepressants (according to predefined list), which have been unchanged for at least 4 weeks before inclusion and no change in antidepressants is anticipated,
3. sufficient knowledge of the Danish language.

Exclusion Criteria:

1. risk of suicide is high according to clinicians or assessment researchers
2. alcohol or drug dependence,
3. cluster A or B (DSM-5) personality disorder diagnosed by intake clinicians or assessment researcher,
4. co-morbidity of pervasive developmental disorder, psychotic disorders, eating disorders, bipolar disorder, or severe physical illness,
5. psychopharmacological treatment other than those predefined as acceptable,
6. patient does not accept to stop the use of anxiolytics within the first four weeks of intervention.

The datasets generated by the planned study will not be publicly available due to the rules of the Danish Data Protection Agency, but will be available from the corresponding author, after publication, on reasonable request and following signed confidentiality agreement with PI and the Danish Data Protection Agency Region Zealand.