Lithium in the over-65s: who is taking it and who is monitoring it? A survey of older adults on lithium in the Cambridge Mental Health Services catchment area.

Abstract

To determine the prevalence of lithium therapy in the over-65s in the Cambridge Mental Health Services catchment area, to obtain a profile of this group and to find out how well and by whom lithium treatment is being monitored. A census was carried out of patients over the age of 65 in the Cambridge Mental Health Services catchment area who were on lithium therapy on 1 February 1995. The records of these patients were examined retrospectively for demographic details, details of lithium therapy, information about lithium monitoring and risk factors associated with lithium treatment. One hundred and forty-eight patients were identified representing a point prevalence of 0.27%. GPs carried out lithium monitoring for the majority of this group and 47% had not been seen by a psychiatrist in the 12 months leading up to the census date. Thirty-two per cent of the group were on thyroxine treatment or had raised TSH levels. The prevalence of lithium therapy in this study was greater than the prevalences reported in studies of patients of all ages. Standards of monitoring varied widely and were not always better where psychiatrists monitored the treatment, although psychiatrists were more likely than GPs to monitor renal function. There was a high rate of thyroid dysfunction in the study group.