Some recent developments in psychiatric genetics.

The methods and results of some recent family, twin and adoption studies of childhood behaviour disorders, crime, alcoholism, psychopathic personality and neurosis are briefly described. The data of Slater (1938) on the parents and children of manic-depressives are reanalysed. Bipolar affective illness were more frequent in the families of bipolar than unipolar probands. There was no support for sex-linked inheritance in either group or for further genetic subdivision of the unipolar group according to age of onset or alcoholic or psychopathic family history. It is suggested that for the time being we may have to be satisfied with three broad and aetiologically overlapping clinical types of depression: bipolar, unipolar and reactive.