The study evaluates cost and effect of inpatient versus outpatient treatment of dysthymia, as well as investigates the processes through which psychotherapy works in treating dysthymia.

Inpatient treatment allows a more intensive treatment and allows the patient to be in a context where it is possible to focus on the processes in therapy with minimal interruption. Outpatient treatment is much less intensive but allows the treatment process to unfold in the context where the patient is experiencing the problems that brought them to therapy. It is not clear which of the contexts will be more effective in alleviating symptoms of dysthymia. Further, as dysthymia is a very costly disease for society it is of interest to know if the two treatments are cost-effective, and which one is the most cost effective.

A great paucity on dysthymia research ha left the psychotherapy field without an understanding of the processes through which dysthymia is changed. This study will investigate the change process through frequent assessments of common factors, psychological processes, symptoms, heart rate variability and cognitive attention bias.

Inclusion Criteria:

• Inclusion criteria will be liberal and similar to clinical practice criteria at the treatment site: Persistent depressive disorder as defined by the diagnostic and statistical manual of mental disorders (DSM5); which includes an International classification of disorders-10 (ICD-10) diagnosis of depression, dysthymia, recurrent depression. unsuccessful previous treatments. living within driving distance from the treatment facilities.

Exclusion Criteria:

• current suicidal risk, current psychosis, marked emotional instability (i.e. issues with impulsivity), strong paranoid traits, current problems related to heavy substance abuse.