Table 2. Demographic and clinical characteristics of the participants in Swedish twins at age 15, 18 and 20–28 years.
| Cohort | CATSS-15 | CATSS-18 | YATSS 20–28 |
|---|---|---|---|
| Total, n | 7,905 | 2,495 | 6,218 |
| MZm, n (%) | 922 (11.66) | 247 (9.9) | 1,006 (16.2) |
| MZf, n (%) | 1,234 (15.6) | 433 (17.4) | 1,633 (26.3) |
| DZm, n (%) | 1,158 (14.7) | 337 (13.5) | 616 (9.9) |
| DZf, n (%) | 1,219 (15.4) | 370 (14.8) | 975 (15.7) |
| DZos, n (%) | 2,634 (33.3) | 846 (33.9) | 1,761 (28.3) |
| Unknown zygosity, n (%) | 738 (9.3) | 262 (10.5) | 227 (3.7) |
| Twins from complete pairs, n | 6,254 | 1,786 | 4,028 |
| Singletons, n | 913 | 447 | 1,963 |
| Mean HRS-SR score (SD) | 4.4 (4.7) | 3.8 (4.5) | 3.8 (3.9)a |
| Hoarding symptoms, % (95% CI) | 1.5 (1.3–1.8) | 0.9 (0.6–1.4) | 0.8 (0.6–1.1) |
Note: HRS-SR = Hoarding Rating Scale-Self Report; SD = standard deviation; CI = confidence interval; MZm = male monozygotic twins; MZf = female monozygotic twins; DZm = male dizygotic twins; DZf = female dizygotic twins; DZos = opposite-sex dizygotic twins.
a Mean score based on 4 items (difficulty discarding, clutter, acquisition and distress) from HRS-SR.