Table 1.
Onsets of major depression in the last year across the four waves of assessment in the female-female twin sample and two waves of assessment in the male-female twin sample
| Number of onsets of MD (% of subjects)b | ||||||||
|---|---|---|---|---|---|---|---|---|
| Cohort | Sex | Wave | Total N | Total eligible, Na | Total | Prior episode | No prior episode | |
| Cohort 1 | F | 1 | 2163 | 2137 | 204 (9.5%) | 126 (19.0%) | 78 (5.3%) | |
| Cohort 1 | F | 2 | 2003 | 1979 | 185 (9.3%) | 109 (16.0%) | 76 (5.9%) | |
| Cohort 1 | F | 3 | 1898 | 1871 | 155 (8.3%) | 132 (16.3%) | 23 (2.2%) | |
| Cohort 1 | F | 4 | 1943 | 1911 | 176 (9.2%) | 141 (16.9%) | 35 (3.2%) | |
| Cohort 2 | F | 1 | 1729 | 1650 | 146 (8.8%) | 92 (16.8%) | 55 (4.9%) | |
| Cohort 2 | F | 2 | 1402 | 1335 | 169 (12.7%) | 129 (19.5%) | 40 (6.0%) | |
| Cohort 2 | M | 1 | 5114 | 4904 | 282 (5.8%) | 143 (12.3%) | 139 (3.7%) | |
| Cohort 2 | M | 2 | 4240 | 4079 | 287 (7.0%) | 219 (14.3%) | 68 (2.7%) | |
F, Female; M, male; MD, major depression.
a
Were not eligible for MD onset either because they were in an episode of MD the entire year or because of missing data.
b
For simplicity, we do not present the number of subjects in each cohort and wave who have υ. have not had a prior depressive episode which represent the denominator used for the calculation of the percentages of MD onsets in these two groups presented in the last two columns of the table.