Objectives: we measured subjective memory impairment (SMI) across the whole adult age range in a representative, national survey. Age is the strongest risk factor for dementia and SMI may be a precursor of objective cognitive impairment. We therefore hypothesised that SMI prevalence would rise with age in a non-demented population.
Method: we analysed data from the English 2007 Adult Psychiatric Morbidity Survey, representative of people in private households. Participants were asked whether they had noticed problems with forgetting in the last month, or forgotten anything important in the last week; and completed the modified Telephone Interview for Cognitive Status.
Results: of those contacted, 7,461 (57%) participated. After excluding participants screening positive for dementia, 2,168 (31.7%) reported forgetfulness in the last month, while 449 (6.4%) had forgotten something important in the last week. Reporting forgetfulness was not associated with age. In a multivariate analysis including cognition and age, the only significant associates of reporting forgetfulness were anxiety, depressive and somatic symptoms.
Conclusions: our hypothesis that subjective forgetfulness prevalence would rise with age in a non-demented population was not supported. Although subjective forgetfulness can be an early symptom of future or mild dementia, it is common and non-specific and-at population level-is more likely to be related to mood than to be an early symptom of dementia. Asking those presenting with subjective forgetfulness additional questions about memory and functional decline and objective forgetfulness is likely to help clinicians to detect those at risk of dementia.