Study Where Pharmaco Magnetic Resonance Imaging (MRI) Effects of AZD6765 Will be Compared to Placebo in Depressive Male and Female Subjects

A Phase I, Multi-centre, Double-blind, Placebo-controlled Parallel Group Study to Assess the pharmacoMRI Effects of AZD6765 in Male and Female Subjects Fulfilling the Criteria for Major Depressive Disorder

The purpose of this study is to determine the effect of a single dose infusion of AZD 6765 compared with placebo and ketamine on the blood oxygen level dependent signal using fMRI (functional Magnetic Resonance Imaging) in depressed subjects.

Inclusion Criteria:

• Documented clinical diagnosis meeting criteria from the DSM-IV by structured clinical interview,major depressive disorder, single episode or recurrent
• Outpatient status at screening and at randomisation

Exclusion Criteria:

• A major depression disorder which has a major impact on the subjects current psychiatric status
• Subjects not allowed to use mood stabilizers, antidepressants or other antipsychotic or psychoactive drugs
• Subjects with lifetime history of schizophrenia, bi-polar, psychosis and psychotic depression