Recovery From Schizophrenia: Psychiatry And Political Economy

WHAT IS SCHIZOPHRENIA? 17intrusiveness at home, for example) or existential concerns (loss of a sense ofpurpose or belonging).Once an episode of psychosis has begun, these same stressors and new ones,together with the degree of vulnerability, will determine the subsequent courseand outcome of the illness. Labeling and social stigma may affect the individual’ssense of self-worth, as may his or her success in reintegrating with the socialgroup and in returning to a valued social role. Criticism, rejection, restriction,confinement or idleness might well limit the individual’s capacity for recoveryfrom schizophrenia.The strength of some of these potential causes of vulnerability and precipitantsof psychosis has been better demonstrated than others. On the following pages afew of the more important will be briefly outlined.InheritanceIf inheritance is important in the development of schizophrenia, relatives ofpeople with schizophrenia will have a greater risk of developing the illness thanothers—and they do. One would also expect the risk to be progressively greaterin relatives who are more genetically similar to the schizophrenic person.Epidemiologist Irving Gottesman, drawing data from about 40European studies conducted between 1920 and 1987, compiled a comparison ofthe average lifetime risk of developing schizophrenia for people with differentdegrees of relationship to someone with schizophrenia. His findings, shown inFigure 1.3, indicate that the closer the similarity in genetic make-up, the greaterthe risk. The identical twins of people with schizophrenia, who have precisely thesame genetic constitution, run the greatest risk of developing the illness—nearly50 per cent. The offspring of parents both of whom have schizophrenia have asimilar risk. The rate is less for first-degree relatives such as non-identical siblingsand progressively declines through second-degree and third-degree relatives to thegeneral population risk of around one per cent. 32Studies of people adopted in infancy suggest that the increased risk ofschizophrenia in the relatives of identified cases is related to inheritance ratherthan environment. The children of people with schizophrenia have a similarincreased prevalence of the illness whether they are raised by their biologicalparents or by adoptive parents. Likewise, the family history of people withschizophrenia brought up by adoptive parents reveals an increased prevalence ofthe illness among their biological relatives but not among their relatives byadoption. 33Genetic factors appear to be important in the development of schizophreniabut are not sufficient to explain the entire pattern of occurrence. As we haveseen, although identical twins have exactly the same genetic make-up, the risk ofthe second twin developing schizophrenia is only 50 per cent. One may concludethat genetic factors play a major part in establishing the vulnerability to the illnessbut that environmental factors (including the intrauterine experience) must also