“…For example, drugs which act on monoaminergic neuron systems, such as adrenergic, serotonergic, and dopaminergic systems, as well as GABAnergic and peptidergic neuron systems, are recognised to be ecacious for treating depression. Therefore, some functional abnormalities in these neuronal systems have been assumed to be related to the pathogenesis of depression (Okada and Tokumitsu, 1994). Recently, it has been thought that immunological abnormalities might be related to the pathogenesis of depression, since depression is sometimes caused by interferon therapy (Okada, 1995a).…”