[A history of famous hypotheses and the future development of studies on affective disorders]

The two famous hypotheses for the pathophysiology of affective disorders examined the role of deficiencies in catecholamine(Schildkraut, 1965) and indoleamine(Coppen, 1967). In the catecholamine hypothesis, Schildkraut proposed that some depressions were associated with an absolute or relative decrease in available norepinephrine at central adrenergic receptor sites. In the indoleamine hypothesis, there was evidence that the biochemical disturbances in three main areas; in amine metabolism, electrolyte distribution and hormonal function, played a role in affective disorders. This review attempts to find newer studies of affective disorders influenced by the two hypotheses. With the development of neurobiology and the availability of new tools over the last three decades, authors have generated newer theories for current studies. The functional roles of GABA, glutamate and dopamine have lead to the generation of newer hypotheses. The neurogenesis hypothesis provides evidence of a novel concept for the pathophysiology of affective disorders.