Acceptance and Commitment Therapy Versus Cognitive Therapy for the Treatment of Major Depressive Disorder

Acceptance and Commitment Therapy vs. Cognitive Therapy for the Treatment of Major Depressive Disorder

The study will investigate the effectiveness of Cognitive Therapy and Acceptance and Commitment Therapy in a randomized controlled trial among patients with Major Depressive Disorder in routine clinical practice. Furthermore, the study will investigate whether each specific treatment approach is mediated by its proposed theoretical mechanism.

The current study aims at investigating the effectiveness of Cognitive Therapy and Acceptance and Commitment Therapy in a randomized controlled trial among patients with MDD in routine clinical practice. Further, the study will investigate whether each specific treatment approach is mediated by its proposed theoretical mechanism. Patients have to meet diagnostic criteria for nonpsychotic MDD as determined by the Structured Interview for DSM-IV. Each client will receive either Cognitive Therapy or Acceptance and Commitment Therapy that will last between 16 to 20 sessions. Based on previous results, it is expected that both treatment forms will prove beneficial for the patients.

Inclusion Criteria:

1. Meeting DSM-IV criteria for MDD
2. Between the ages of 18 and 65-years-old
3. Having sufficient fluency in Dutch to complete treatment and research protocol

Exclusion Criteria:

1. DSM-IV criteria for bipolar disorder (past or present)
2. Psychotic disorders
3. Substance dependence disorders (current or within the past 6 months), or
4. Organic brain syndrome.
5. Borderline or antisocial personality disorder