Venlafaxine Augmentation in Treatment Resistant Depression

Inclusion Criteria: * Female and male inpatients with a major depressive disorder without psychotic features or with a depressive episode within a bipolar I or II disorder without psychotic features * Ages between 20 and 70 years * Total score greater than 18 on the Hamilton Depression Rating Scale * Documentation of at least one ineffective antidepressant drug trial under adequate dosage for at least 6 weeks in the current episode Exclusion Criteria: * Other psychiatric axis I disorders than those mentioned as Inclusion criteria * Acute suicidality (Item 3 of the Hamilton Depression Rating Scale greater than 2) * Drug or alcohol addiction * Patients with severe hepatic, cardiovascular, neurologic, metabolic or malignant disorders * Documentation or report of a previous ineffective treatment trial with venlafaxine, lamotrigine or quetiapine * Functional kidney disorders * Untreated hypertension * Acute treatment with thyroid hormone (less than 3 months) * Pregnant or nursing patients * Women of childbearing age without effective contraception