Table 1.
Characteristics of each group
| HCs | AD | PD | DLB | MDD | p | |
| N | 54 | 45 | 20 | 21 | 19 | |
| Age (y) | 77.0±5.6 | 77.3±4.4 | 75.8±4.2 | 77.8±7.5 | 70.7±7.6* | p < 0.001a |
| Sex (male/female) | 18/36 | 15/30 | 6/14 | 7/14 | 7/12 | p = 0.995b |
| MMSE | 18.2±5.5 | 27.2±3.3 | ||||
| Duration (y) | 4.2±4.1 | |||||
| NPI | 13.8±16.5 | |||||
| MADRS | 5.9±4.9 | |||||
| ADAS | 19.5±9.0 | |||||
| CDR | 1.5±0.6 | |||||
| L-dopa (mg/day) | 415.4±116.2 | |||||
| UPDRS | 27.9±11.3 | |||||
| HAM-D21 | 22.8±10.1 |
Data are shown as mean±standard deviation. HCs, healthy controls; AD, Alzheimer’s disease; PD, Parkinson’s disease; DLB, dementia with Lewy bodies; MDD, major depressive disorder; MMSE, Mini-Mental State Examination; NPI, Neuropsychiatric Inventory; MADRS, Montgomery–Åsberg Depression Rating Scale; ADAS, Alzheimer’s Disease Assessment Scale; CDR, Clinical Dementia Rating; L-dopa, L-3, 4-dihydroxyphenylalanine; UPDRS, Unified Parkinson’s Disease Rating Scale; HAM-D21, 21-item Hamilton Depression Rating Scale. *Dunnett’s test, p < 0.001 (HCs versus MDD). aOne-way analysis of variance. bχ2 test for independence.