Table 1.
Demographic and cognitive domain score differences by APOE genotype and diagnostic group
| APOE ε4 − Depressed (N = 51) | APOE ε4 − Nondepressed (N = 56) | APOE ε4 + Depressed (N = 21) | APOE ε4 + Nondepressed (N = 29) | Test Statistic | p value | |
|---|---|---|---|---|---|---|
| Age (y) | 36.5 (8.8) | 29.2 (8.2) | 36.8 (8.8) | 31.4 (10.1) | F = 7.69 | p < 0.0001 |
| Sex (% female) | 66.7% (34) | 58.9% (33) | 76.2% (16) | 68.9% (20) | χ2 = 2.32 | p = 0.5088 |
| Race (% Caucasian) | 64.7% (33) | 51.8% (29) | 61.9% (13) | 51.7% (15) | χ2 = 2.39 | p = 0.4955 |
| Education (y) | 15.5 (2.5) | 15.8 (1.9) | 14.7 (2.1) | 16.1 (2.4) | F = 1.83 | p = 0.1434 |
| MADRS | 23.9 (4.2) | 0.6 (0.9) | 24.4 (5.2) | 1.31 (1.4) | F = 692.83 | p < 0.0001 |
| Episodic Memory | −0.76 (4.16) | 0.92 (4.02) | −1.35 (4.22) | 0.62 (3.40) | F = 0.38 | p = 0.7675 |
| Executive Function | −0.95 (3.07) | 0.49 (3.12) | 0.13 (2.97) | 0.40 (3.06) | F = 1.67 | p = 0.1762 |
| Processing Speed | −0.76 (2.35) | 0.57 (2.39) | −0.28 (1.89) | 0.30 (2.46) | F = 1.21 | p = 0.3094 |
| Working Memory | −0.28 (1.68) | 0.48 (1.75) | −0.10 (1.68) | −0.15 (1.72) | F = 1.13 | p = 0.3383 |
Continuous measures presented as mean (standard deviation). Group differences in demographic variables (age, education, MADRS score) tested using analysis of variance (ANOVA) where the model had a total 156 degrees of freedom. Categorical variables presented as percentage (number), differences tested using chi-square with 3 degrees of freedom. Cognitive domain data presented as z-transformed scores, mean (SD). These cognitive domain models tested for 4-way group differences and included 147 degrees of freedom, controlling for age, sex, education, and race.