title: Plasma cyclic AMP in manic-depressive illness.
abstract: The postulated disturbance of cyclic AMP (cAMP) in manic-depressive illness was investigated by using plasma as the biological material. Cyclic AMP was measured by a protein-binding assay, which was found very satisfactory for the purpose of this study. In the drug-free state, depressed patients (n = 28) had significantly lower and manic patients (n = 9) significantly higher plasma concentrations of cAMP than controls. Unmedicated manic-depressive subjects had normal cAMP levels during normothymic phases (n = 7). Cyclic AMP was reduced by neuroleptics in mania and elevated by tricyclics in depression. Lithium exerted a normalizing effect on cAMP in both phases of the illness. It is concluded that manic-depressive illness is associated with a disturbance in the cAMP system. The use of plasma rather than urine for the investigation of the state of cAMP in psychiatric disorders is advocated.
mesh_terms: D000328:Adult; D000368:Aged; D000929:Antidepressive Agents, Tricyclic / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000097:blood* / Q000188:drug therapy; D000242:Cyclic AMP / Q000097:blood*; D006801:Humans; D008094:Lithium / Q000627:therapeutic use; D008875:Middle Aged; D014149:Tranquilizing Agents / Q000627:therapeutic use
chemical_list: D000929:Antidepressive Agents, Tricyclic; D014149:Tranquilizing Agents; D008094:Lithium; D000242:Cyclic AMP