Platelet MAO in children with attention deficit disorder and hyperactivity: a pilot study.

The authors examined platelet MAO activity in 8 hyperactive and 18 control children who were admitted to a clinical research center and placed on a low monoamine diet. After 5 days, their blood was analyzed; the hyperactive children were discharged on day 7, placed on d-amphetamine for 2 weeks, and readmitted for repeat blood analysis. The hyperactive children initially had significantly lower levels of platelet MAO than the controls. After the hyperactive children were treated with d-amphetamine for 2 weeks, their platelet MAO levels were comparable to those of the control children. The authors suggest an association between low platelet MAO activity and a behavioral state of overactivity, short attention span, and impulsivity.