Background: Neuro-hormonal and hemostatic mechanisms are important in a wide range of psychological and cardiovascular diseases. The use of psychoactive drugs in mental illnesses is often involved with hematologic side effects including impaired platelet function. Subsequently, the risk for the development of cardiovascular diseases may be higher in these patients. Interestingly, platelets that play a key role in cardiovascular complications contain quite a number of neuronal receptors which are involved in psychotic disorders. It has been widely discussed whether psychoactive drugs used in the therapy of psychotic disorders have a direct effect on platelet function and whether the effects are transmitted through the corresponding receptors on the platelet surface. Material and Methods: In this study, we tested several psychoactive drugs regarding their impact on whole blood platelet aggregation. Results: Antidopaminergics preferentially inhibited ADP-induced aggregation whereas anticholinergics mainly inhibited U46619induced aggregation. Because platelets respond selectively to different psychoactive drugs we assume that corresponding receptors have a functional aspect on platelets and that receptor blockade affects platelet aggregation through different mechanisms. Conclusion: The knowledge about the effects of psychoactive drugs on platelet function may help to characterize neuronal receptors on platelets and may contribute to a better understanding of altered platelet function during therapy with psychoactive drugs.