Noradrenaline, dopamine and mood

It has recently been pointed out that one neurotransmitter is unlikely to be the single mediator of a specific mental disorder; neither is it likely that each class of psychiatric drugs works via a single neurotransmitter system only. Yet the history of medicine would seem to teach that the search for specificity brings progress. The identification of a step in the expression of schizophrenic symptoms that is "dopamine-blockade sensitive" has been most heuristic. Amphetamine and related stimulant drugs in the brain release several monoamine neurotransmitters. In a series of experiments we have attempted to identify whether specific aspects of the response to stimulant drugs can be blocked or mimicked by other drugs that affect various neurotrairsmitters. This paper will review our studies of: 1. 1. Haloperidol blockade of the mood response to methylphenidate in lithium-treated patients; 2. 2. Salbutamol infusion effects on depressed patients; 3. 3. The effects of chronic lithium on stimulant-induced behavior in rats.