IS PERSONALITY-DISORDER INHERITED - AN OVERVIEW OF THE EVIDENCE

Genetic factors appear to be of considerable importance in determining normal variation in personality. This is suggested by family, twin, a nd adoption studies as well as by indirect findings based on animal an d psychophysiological studies. In contrast, there is consistent eviden ce that the contribution of shared family environment is minimaL Despi te difficulties in defining personality disorder, it appears that many types of personality disorder, in particular schizotypal personality disorder and antisocial personality disorder/criminality, are also inf luenced genetically. The genetic transmission of normal personality tr aits and disorder is most easily explained by the contribution of mult iple genes of small effect rather than by single-gene inheritance. Rec ent advances in molecular genetics have led to the localization of gen es of minor effect for some traits. This raises the possibility of det ecting a molecular basis of traits and disorders such as personality a nd personality disorder.