Delusional infestation in late life.

TLDR: In this age group delusions of infestation may be less persistent and pernicious than those of the monosymptomatic psychoses that are reported more commonly in younger middle-aged patients, and the presence of some organic impairment should not detract from the treatability of the condition through an appreciation of the mood disorder.

Abstract: SIR: Renvoize et a! (Journal, March 1987, 150, 403—405)provide a useful review of the literature, including the German literature, in reporting their interesting patient whose delusions of infestation occurred during the course of a dementing illness. We have been interested to find that delusions of infes tation are seen quite commonly among the patients referred to our psychiatric services for the elderly and we recently reviewed seven cases that presented between 1983and 1986.There were two men and five women. Their ages ranged from 69 to 76—a little above the boundary of †̃¿ late middle age', the age group from which patients are most frequently reported, but not very old (patients aged 75 and above constitute about three quarters of our referrals). All seven were found to be depressed. None were seriously demented, although in three there was clear evidence of some organic cerebral impairment and in only one could we be sure that there was no such pathology. In two patients the delusions of infes tation developed in the context of guilt at not main taining cleanliness in the home after the death of a spouse. In three, previous neurotic preoccupation with cleanliness or †̃¿ phobia' of †̃¿ creepy-crawlies' had become delusional in the setting of severe depression, and in the last two the delusion was part of a systematic belief that the body was changed and degenerating. In most of our patients the delusions appeared when powerful change of affect occurred with mild organic change. This is a potent combination in the genesis of delusions (Hay et al, 1974). Successful treatment of the mood disorder has led to resolution of the delusions of infestation in the six cases we have known longest. Thus, in this age group delusions of infestation may be less persistent and pernicious than those of the monosymptomatic psychoses that are reported more commonly in younger middle-aged patients. The presence of some organic impairment should not detract from the treatability of the condition through an appreciation of the mood disorder. MICHAEL Moiuus DAVID J. JOLLEY Reference