Subjective memory complaint in relation to cognitive performance and depression: A longitudinal study of a rural Chinese population

OBJECTIVES: To examine the associations of subjective memory complaint (SMC) in old age with (a) objective test performance, (b) past and subsequent cognitive decline, and (c) depression. DESIGN: A group of community residents were examined twice during a 3-year period. SETTING: Two townships on a rural Chinese islet. PARTICIPANTS: A total of 543 men and women aged 65 years and older. MEASUREMENTS: During each examination, neurologists interviewed and examined all participants for dementia and asked the question, "Do you have trouble with your memory?" In addition, research assistants administered (a) the Cognitive Abilities Screening Instrument (CASI) to assess cognitive abilities, including long-term memory (LTM) and short-term memory (STM), and (b) the Geriatric Depression Scale-Short Version (GDS-S) to assess symptoms of depression. RESULTS: At each examination, almost half of the subjects acknowledged having trouble with their memory (the SMC+ group). At both examinations, the SMC+ group scored significantly lower on the CASI and significantly higher on the GDS-S than the SMC- group. However, the presence of SMC was not associated with faster cognitive decline over the past or subsequent 3 years. There were no consistent associations between SMC and the demographic variables of age, gender, and education at the two examinations. Logistic regression analysis showed that SMC was associated with poorer memory test scores after controlling for gender, age, education, and depression. CONCLUSIONS: SMC was associated with poorer objective memory performance even after controlling the effect of depression and demographic data, but SMC did not predict faster cognitive decline or dementia over 3 years.