Variations in the Hoffmann reflex recovery curve related to clinical manifestations of schizoaffective disorder.

Recovery curves of the Hoffmann reflex (H reflex) were measured in both legs of 10 unmedicated inpatients with schizoaffective disorder, depressed type. Neither recovery curve height of the right leg nor that of the left leg was significantly correlated with clinical psychopathology, although a consistent negative relation was noted between recovery curve height of the left leg and psychopathology. Right-left differences in recovery curve height significantly correlated with both Brief Psychiatric Rating Scale and Hamilton Rating Scale for Depression ratings of psychopathology, such that relative elevation of the recovery curve of the right leg or relative lowering of the recovery curve of the left leg correlated with symptom severity. Three patients who later developed psychotic symptoms when treated with bupropion, a dopaminergic agent, had lower recovery curves, indicative of increased central dopaminergic activity. Relatively lower left-sided recovery curves may reflect increased dopaminergic activity on the right side of the brain in schizoaffective disorder, compared to the left in schizophrenia.