Background and aims: Apathy; defined as a loss of interest and/or emotion, occurs in several neuropsychiatric conditions and may complicate type 2 diabetes. The aim of the present study was to assess the prevalence and incidence of apathy and potential causes in a non-demented, independently living patient sample from the Fremantle Diabetes Study (FDS).
Patients and methods: Type 2 FDS patients (n=121, age 73.4±7.0 years) with long duration diabetes (≥14 years) and suitable informants were studied at baseline and after 16.8±2.5 months (n=101). Informants completed the 14-item Apathy Scale (score ≥14 defines apathy) and the patients were rated using the Mini-Mental State Examination (MMSE), the Clinical Dementia Rating scale (CDR) and the 9-item Patient Health Questionnaire (PHQ-9) for depression.
Results: At baseline, apathy was present in 37.2%, the median MMSE score was 29 (inter-quartile range 28-30), 28.9% had mild degree cognitive impairment (CDR=0.5) and 14% had (mostly minor) depression. Apathy was associated with depression and cognitive impairment in univariate analysis (P<0.05) but with logistic regression, only cognitive impairment was associated with apathy (odds ratio (95%CI): 2.54 (1.01-5.88). At follow up, apathy improved in 13 patients (12.9% of the follow-up sample), persisted in 24 (23.8%) and new onset apathy occurred in a further 10 patients (9.9%) giving a follow up prevalence of 33.7%. Incident apathy was not associated with baseline cognition or depression, or by change in MMSE or depression scores but was associated with cognitive decline as assessed by change in CDR rating (chi-square 3.93, P=0.048).
Conclusion: In our sample, the prevalence and annual incidence of apathy was high although apathy assessments exhibited some instability. Apathy in type 2 diabetes appears to be common and associated with mild and often sub-clinical cognitive impairment. Unrecognised apathy may complicate the management of type 2 diabetes in older patients with long-standing diabetes