Environmental and Hereditary Factors in the Schizophrenias of Old Age (“Late Paraphrenia”) and their Bearing on the General Problem of Causation in Schizophrenia
D. W. K. Kay, Martin Roth


1. A clinical follow-up and genetic study has been made of 99 patients aged 60 years and over (with a mean age of about 70) suffering from “late paraphrenia”. The patients consist of two groups, one from the Psychiatric Hospital, Stockholm (1931–1940)and the other from Graylingwell Hospital, Chichester, Sussex (1951–1955). Patients with affective and organic disorders of similar age and admitted during the same periods are used for comparison. Both paraphrenic groups show the same characteristics which may be summarized as follows:

(i)Females predominate over males in the ratio of about 7:1, i.e., significantly in excess of expectation. In both sexes unmarried patients are significantly more, and married patients less common than in the general population of similar age. Fertility among ever-married patients is low.

(ii)An examination of the background of the illness shows that significantly more paraphrenics were living alone at the time of falling ill than those with affective disorder. This appears to have been due to several factors, i.e., the frequency of the unmarried state and the low fertility among the paraphrenics, who also had fewer surviving sibs.

(iii)Of those living alone, many more patients with paraphrenia than with affective disorder were socially “isolated”. Three factors seem to be responsible: (1) deafness (2) abnormalities of personality (3) few surviving relatives. Deafness of some degree was found in 40 per cent. of the Graylingwell paraphrenics and of severe degree in some 15 per cent. of all cases, with a much lower incidence among the other groups. Personality traits among paraphrenics and affectives also differed markedly. Among the former they were commonly of paranoid schizoid type and contributed substantially to failure to marry, social isolation and probably to the development of the psychosis itself. But factors unconnected with the personality, such as absence of relatives, played some part in deciding whether isolation did or did not occur.

(iv)Except in one subgroup, referred to below, the clinical picture is remarkably uniform and is characterized by the presence of many schizophrenia like disorders of thought, mood and volition, by relatively good preservation of formal intellect, personality and memory, and by conspicuous hallucinations. In about 20 per cent. of the Graylingwell cases hallucinosis was entirely absent and the illness appeared to represent a caricaturing of deviating personality traits of long standing; these cases may perhaps be regarded as “paranoid reactions” to the physical and social consequences of growing old. But exogenous factors (deafness, isolation) or personality attributes are always to a greater or lesser extent in evidence, and it is doubtful if any clear lines of demarcation between groups of cases really exist. At this stage therefore it seems far more profitable to treat the “late paraphrenias” as a whole.

(v)An inherited predisposition to late paraphrenia must be postulated, but this is likely to be of lesser degree than in schizophrenia occurring early in life. The mode of inheritance is probably multifacturial.

(vi)A pathological degree of cerebral degeneration is probably related to the onset of psychosis in not more than 5 percent. of cases. Normal age specific mental changes may have been responsible in a further proportion of cases for a caricaturing of previous abnormalities of personality and to this extent have contributed to the development of the psychosis.

(vii)The course of the illness tends to be chronic and the changes of schizophrenic type usually become more prominent, but sometimes a “burnt out” state with residual defects is seen. Occasionally the illness merges after many years into a state difficult to distinguish from that of senile dementia (12 per cent.). Signs of focal cerebral disease, including isolated seizures, eventually appear in a further 9 percent. The mean life span is only very slightly shorter than normal, a fact which distinguishes late paraphrenia sharply from senile and arteriosclerotic psychoses where life expectation is less than one quarter of the normal.

2. The clinical homogeneity of the group, its relationship to schizophrenia, the influence of genetic and organic factors, and the roles of social isolation, lack of relatives, deafness, and abnormalities of the personality are discussed.

3. It is concluded that late paraphrenia has to be regarded as the mode of manifestation of schizophrenia in old age. The aetiological factors identified in late paraphrenia are therefore likely to have some relevance for the problem of causation of schizophrenia itself. It is considered that the setting of social isolation in which a high proportion of paraphrenic cases are found is due to some extent to a self-segregation of personalities for whom social contact and communication are difficult or stressful. But the evidence suggests that isolation must be attributed to some extent to accidental factors such as deafness, position in sibship or scantiness of surviving relations. The accumulating effects of such factors may account for final breakdown in old age. At younger ages also, the onset of schizophrenia is likely sometimes to be due to isolation, and not merely a cause of it. The findings perhaps also have some bearing on the general problem of social isolation in relation to mental illness.