Pterins and affective disorders

The pathophysiology of affective disorders is largely unknown. In patients with various affective disorders the activity of pterins and related amino acids were investigated before and after clinical treatment. In particular the bipolar affective disorder could be characterized by less activity of tetrahydrobiopterin resulting in decreased synthesis of nitric oxide. After clinical recovery the same results were seen implicating that disturbances in the pterin metabilism could reflect a vulnerability for mood disorders.