Table 1.
Characteristics of study sample*
| Major depressive disorder | |||
|---|---|---|---|
| Never | Past | Current | |
| Demographics | |||
| Age, years | 76 ± 5 | 74 ± 5 | 74 ± 5 |
| Female, % | 58 | 69 | 66 |
| Education, % | |||
| primary | 23 | 20 | 19 |
| secondary | 50 | 57 | 57 |
| college/university | 27 | 23 | 24 |
| MMSE score | 27 ± 3 | 27 ± 2 | 27 ± 2 |
| Concerns memory is worse, % | 30 | 38 | 60 |
| Vascular factors | |||
| Smoking status, % | |||
| non-smoker | 43 | 40 | 37 |
| former | 45 | 43 | 44 |
| current | 12 | 17 | 19 |
| Alcohol intake now, % | 66 | 62 | 52 |
| BMI, kg/m2 | 27 ± 4 | 28 ± 4 | 28 ± 5 |
| Systolic blood pressure | 143 ± 20 | 138 ± 18 | 139 ± 20 |
| Diastolic blood pressure | 74 ± 10 | 74 ± 10 | 74 ± 10 |
| Diabetes Mellitus, % | 11 | 16 | 18 |
| History of stroke, % | 6 | 7 | 13 |
| MRI parameters | |||
| Infarcts on MRI, % | 31 | 22 | 24 |
| Absolute WML volume, ml | 13 (4 – 45) | 11 (3 – 37) | 15 (6 – 45) |
| Total ICV, ml | 1503 ± 149 | 1470 ± 128 | 1492 ± 153 |
| GMF, % | 45 ± 3 | 46 ± 3 | 45 ± 3 |
| WMF, % | 26 ± 2 | 26 ± 2 | 25 ± 1 |
| BPF, % | 72 ± 4 | 73 ± 4 | 71 ± 4 |
| Depression measures | |||
| GDS score 6+, % | 5 | 19 | 60 |
| GDS score, median (10–90%) | 2 (0–4) | 2 (1–8) | 7 (3–12) |
| Current antidepressant use, % | 11 | 54 | 66 |
| History of MDD, % | 0 | 100 | 75 |
| Age of first onset of MDD, % | |||
| <60 years | 0 | 70 | 53 |
| 60 years or older | 0 | 30 | 47 |
| Number of MDD episodes, % | |||
| 1–2 times | 0 | 58 | 43 |
| 3 or more | 0 | 42 | 57 |
*
Table is based on the sample before imputation (never MDD n=4050; past MDD n=125; current MM n=62).
Numbers present means ± standard deviations or %, except for WML volume where median and 10–90 percentile is given.
MDD=major depressive disorder; BMI=body mass index; WML=white matter lesion; ICV=intracranial volume; GMF=gray matter fraction; WMF=normal white matter fraction; BPF=brain parenchymal fraction; GDS=Geriatric Depression Scale.