... the catecholamines (noradrenaline and dopamine) was emphasised as the cause of depressive and manic disorders. (eg Bunney and Davis 1965, Schildkraut 1965,1978, Schildkraut and Kety 1967). It was proposed that deficiency of catecholamines, especially noradrenaline was associated with some depressions and an excess of catecholamines was associated with mania. It was discovered that many antidepressant drugs increase the availability of catecholamines at receptor sites, drugs such as the tricyclics and related antidepressants block presynaptic reuptake of catecholamines and monoamine oxidase inhibitors (MAOI) decrease their deamination resulting in increased amounts available for release. It was also noted that drugs such as amphetamine release catecholamines which have a temporary antidepressant effect and causes euphoria in non depressive people, though it tends to aggravate mania. How dopaminergic activity is related to depression is still uncertain. As in post mortem studies of depressive suicides no changes in brain dopamine concentrations have been found. However ...

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