The Role of Dopamine, Reward Learning and Prefrontal Activity in Expectation-induced Mood Enhancement

The substituted benzamide sulpiride is a selective D2-receptor antagonist that is generally well tolerated and has a low affinity to histaminergic, cholinergic, serotonergic, adrenergic, or GABA receptors. Sulpiride is slowly absorbed from the gastrointestinal tract and peak serum levels occur at 3 hours . In low doses (50-200 mg), sulpiride presumably blocks presynaptic autoreceptors, thereby elevating DA levels and reducing depressive symptoms, whereas higher doses lead to a predominant blockade of postsynaptic receptors. The dose in the present study (400 mg) is sufficient for behaviorally relevant modulations of dopaminergic processing with minimal risk of side effects. Note that participants in the sulpiride group actually receive a dose that is presumably too high to produce antidepressant effects.

Participants receive an inactive placebo capsule.

Participants will be told by the study clinicians that an antidepressive sulpiride capsule is administrated.

Participants will be told by the study clinicians that an inactive placebo capsule is administrated.