Abstract
An attempt is made to review the literature on the relationship between heredity positive for an affective psychosis and outcome in schizophrenic illness. The findings uniformly substantiate the fact that among fully remitting schizophrenics the frequency of relatives with affective psychoses is much higher than in the families of schizophrenics with an unfavourable course. Schizophrenia, on the other hand, appears to occur more often in the families of schizophrenics who do not remit. Statistically, then, in schizophrenia a family history "tainted" with psychosis is favourable only to the extent that such a heredity contains an affective psychosis. This correlation appears sufficiently great to permit heredity to be used in conjunction with other clinical data for the purpose of prognosis.