Prognosis of patients with subjective cognitive decline in an unselected clinical sample

Abstract

AbstractBackgroundIndividuals with subjective cognitive decline (SCD) perceive that their cognition has worsened, but score normally on standardized cognitive tests. It is increasingly recognized that SCD has variable prognosis with the risk of progression to dementia being twice that of age‐matched controls without SCD. This study aimed to characterize an unselected sample of patients with SCD (n = 433) drawn from a larger memory clinic cohort (n = 2,262) and to compare baseline SCD profiles based on follow‐up diagnosis.MethodThis study used routinely‐recorded data from the Essex Memory Clinic (UK). Baseline data included age, sex, years of education, medical and psychiatric history, and physical examination results. A range of neuropsychological measures were administered, and repeated at 12/24‐month intervals. All included patients had at least one follow‐up visit. A consensus diagnosis was made by three clinicians at each visit and was supported by structural CT/MRI investigations. Group comparisons were made using two‐tailed t‐tests, Chi‐squared or Fisher’s exact tests.ResultThe Table presents the results in full. Of 434 patients with SCD diagnosis at baseline, 189 did not progress (SCD‐stable), 169 progressed to dementia (Alzheimer’s = 113; Lewy body = 31; Vascular = 15; Frontotemporal = 4; Other = 6) and a further 76 to mild cognitive impairment (MCI) during follow‐up (median 2.9 years). At baseline there were significant differences between SCD‐stable patients and those who progressed. Patients who progressed to dementia were older than the other two groups. Patients who progressed to MCI/dementia had worse episodic memory (Logical Memory Test delayed and word list recall) and took longer to complete Trail‐Making Test‐A. The SCD‐stable group had higher baseline anxiety and were more likely to have previous psychiatric history versus patients who declined.ConclusionIn this unselected clinical sample from a non‐academic setting, we have replicated and extended previous findings from research cohorts. Whilst anxiety is a risk factor for dementia, anxiety in the context of SCD is associated with a better prognosis and may be an expression of a subclinical affective disorder rather than prodromal neurodegenerative disease. This project demonstrated clear differences at the group level and the next step is to build data‐driven prognostic models that can be applied to individual patients in a clinical setting.