Variable | Early-onset OCD (n = 49) | Late-onset OCD (n = 52) | Healthy controls (n = 103) | Statistical test | p value |
---|---|---|---|---|---|
Male/female, n | 35/14 | 34/18 | 64/39 | χ22 = 1.27 | 0.53 |
Left-handed/right-handed, n | 3/46 | 5/47 | 7/96 | χ22 = 0.55 | 0.76 |
Drug-naïve/unmedicated, n | 17/32 | 24/28 | — | χ21 = 1.37 | 0.24 |
Symptom dimensions, n (%)* | |||||
Aggressive/checking | 17 (35) | 28 (54) | — | χ21= 3.49 | 0.06 |
Contamination/cleaning | 15 (31) | 19 (37) | — | χ21 = 0.22 | 0.64 |
Symmetry/ordering | 17 (35) | 10 (19) | — | χ21 = 3.41 | 0.07 |
Sexual/religious | 6 (12) | 5 (10) | — | χ21 = 0.22 | 0.64 |
Hoarding | 1 (2) | 0 (0) | — | χ21 = 1.10 | 0.30 |
Miscellaneous | 18 (37) | 15 (29) | — | χ21 = 0.89 | 0.35 |
Age, yr, mean ± SD | 23.27 ± 5.16 | 25 ± 4.77 | 25.24 ± 6.86 | F2,201 = 1.89 | 0.15 |
IQ, mean ± SD† | 110.94 ± 9.22 | 110.18 ± 12.88 | 113.13 ± 12.62 | F2,200 = 1.23 | 0.30 |
Total intracranial volume, L, mean ± SD | 1.55 ± 0.13 | 1.50 ± 0.13 | 1.49 ± 0.15 | F2,201 = 2.86 | 0.06 |
Age at onset, yr, mean ± SD | 13.18 ± 2.25 | 21.35 ± 3.51 | — | t87 = −13.98 | < 0.001 |
Duration of illness, yr, mean ± SD | 9.98 ± 5.82 | 3.69 ± 3.24 | — | t74 = 6.65 | < 0.001 |
Y-BOCS score, mean ± SD | |||||
Total | 27.47 ± 5.95 | 26.04 ± 6.54 | — | t99 = 1.15 | 0.25 |
Obsessions | 14.37 ± 3.28 | 13.98 ± 2.65 | — | t99 = 0.65 | 0.52 |
Compulsions | 13.10 ± 3.42 | 12.06 ± 4.80 | — | t93 = 1.27 | 0.21 |
HAM-D score, mean ± SD | 11.10 ± 6.66 | 11.67 ± 5.62 | — | t99 = −0.47 | 0.64 |
HAM-A score, mean ± SD | 10.82 ± 6.89 | 10.62 ± 4.82 | — | t85 = 0.17 | 0.87 |
HAM-A = Hamilton Anxiety Rating Scale; HAM-D = Hamilton Depression Rating Scale; IQ = intelligence quotient; OCD = obsessive–compulsive disorder; SD = standard deviation; Y-BOCS = Yale–Brown Obsessive Compulsive Scale.
↵* As measured using the Y-BOCS symptom checklist.
↵† We assessed IQ using the short form of the Wechsler Adult Intelligence Scale, which includes vocabulary, arithmetic, block design, and picture arrangement subtests.29