Objective: To understand the nature of subjective memory complaints through comparative study of depression status of patients with subjective memory complaints and mild cognitive impairment.
Methods: A total of 214 patients were assessed with the Center for Epidemiologic Studies Depression (CES-D) scale, the Geriatric Depression Scale and some neuropsychological tests. Among them, 76 were of subjective memory complaints (SMC), 74 amnestic mild cognitive impairment-single domain (aMCI-s) and 64 amnestic mild cognitive impairment-multiple domain (aMCI-m).
Results: According to CESD, 31% of the patients had symptoms of depression. The ratios were 30%, 24% and 39% in SMC, aMCI-s and aMCI-m groups respectively. GDS study showed that 43% of the patients had symptoms of depression. The ratios were 47%, 30% and 53% in SMC, aMCI-s and aMCI-m groups respectively. The ratio in SMC group fell between the other two groups. The total score of CESD (12 +/- 10) or GDS (11 +/- 6) of the SMC group, reflecting the severity of depression, fell between aMCI-s (CESD: 11 +/- 8, GDS: 9 +/- 5) and (CESD: 15 +/- 11, GDS: 12 +/- 7) groups. There was no significant difference between them in comparison with either aMCI-s or aMCI-m group (P > 0.05). But the total score of CESD or GDS was significantly different between aMCI-m and aMCI-s groups (P < 0.05). The depression status was worse in aMCI-m group than that in aMCI-s group.
Conclusion: There is no significant discrepancy in the incidence and severity of depression between SMC and aMCI groups. It indicates that depressive mood is not the specific cause of SMC.