The purpose of this study is to compare the efficacy of the Cognitive Behavioural Analysis System of Psychotherapy (CBASP) with the non-specific System of Supportive Psychotherapy (SYSP)in early onset chronically depressives.

Effective treatment strategies for chronic depression are urgently needed since it is not only a common and particularly disabling disorder, but is also considered treatment resistant by most clinicians. There are only a few studies on chronic depression indicating that traditional interventions are not as effective as in acute, episodic depression. In addition, most of the studies had methodological weaknesses, such as the very short courses of psychotherapy. Usually, chronic depression begins early in life, is often associated with early interpersonal trauma, and results in an even more substantial human capital loss than the late-onset group. Furthermore, it shows a weak response to medication and a high rate of relapse after an initial response. With the present multicentre study, the efficacy of the only specific psychotherapy for chronic depression (Cognitive Behavioural Analysis System of Psychotherapy/CBASP) is compared with a non-specific System of Supportive Psychotherapy/SYSP in early onset chronically depressives. CBASP faired very well in one large trial but has never been directly compared to a non-specific psychotherapeutic control. Another innovative aspect of the study is the use of an extended course of psychotherapy (32 sessions). Primary hypothesis: CBASP is more effective in reducing depressive symptoms than SYSP.

A naturalistic study following up the patients of the trial up to two years after termination of the study treatments is performed in order to investigate the long-term effectiveness of CBASP compared to the System of Supportive Psychotherapy. The primary outcome of this follow-up study is the rate of well-weeks (weeks with no or minimal depression symptoms) during the two years after termination of the study treatments as measured with the Longitudinal Interval Follow-up Evaluation (LIFE) Interview

Inclusion Criteria:

1. DSM-IV criteria for a current episode of chronic MDD, MDD superimposed on a pre-existing dysthymic disorder or recurrent MDD with incomplete remission between episodes in a patient with a current MDD and a total duration of at least 2 years.
2. Early onset of the disorder according to DSM-IV (onset before the age of 21)
3. Age between 18 and 65
4. A score of at least 20 on the 24-item HRSD at screening and, after a 2-week drug-free period, at baseline
5. Fluent in German language
6. Provide informed consent

Exclusion Criteria:

1. Acute risk for suicide (as opposed to suicidal thoughts) assessed according to clinical practice guidelines. Suicidal patients are eligible, as long as outpatient treatment is deemed safe by the clinician.
2. A history of psychotic symptoms, bipolar disorder, or organic brain disorders
3. A primary diagnosis of another axis I disorder including anxiety disorders (e.g. Posttraumatic Stress Disorder), or any severe substance-related abuse or dependence disorder as evaluated with the SCID-I
4. Antisocial, schizotypical, or borderline personality disorder (SCID-II);
5. Severe cognitive impairment
6. Absence of a response to previous adequate trial of CBASP, and/or SYSP
7. Other ongoing psychotherapy or medication
8. A serious medical condition (i.e. a history of seizures, severe head trauma, stroke or heart attack within six months before the study began)