Motivational deficit in childhood depression and hyperactivity.

A recent theory states that the immediate cause of adult depression is low motivation, where motivation is the multiplicative product of a person's expectation for a reward times his value for that reward. The present experiment supported the extension of this theory to childhood depression. The expectations, values, and motivations of three groups of children (Ns = 18; mean ages = 10) were measured: A depressed group and a hyperactive control group were selected from a population of clinically disturbed children, while normal controls were selected from regular classrooms. As predicted, the depressed children exhibited reduced motivation, primarily because their expectations were pessimistic. Unexpected findings were that the depressives' expectations were not abnormally irrational; and that hyperactives exhibited optimistic expectations, inflated values, and, hence, inflated motivation--especially for tangible rewards. Cognitive therapy techniques that focus upon expectations were recommended for the treatment of both depressed and hyperactive children.