Demographic and neuropsychiatric characteristics of the traumatic brain injury (TBI) cohort, and in unaffected full siblings
| TBI cohort (n=239 425) | Siblings (n=199 658) | |
| Sex | ||
| Males | 58.9% (140 893) | 49.1% (98 055) |
| Females | 41.2% (98 532) | 50.9% (101 603) |
| Age at incident TBI* | ||
| 18–24 | 18.4% (43 939) | 15.1% (30 232) |
| 25–34 | 12.9% (30 910) | 17.1% (34 123) |
| 35–44 | 11.7% (27 993) | 15.5% (31 035) |
| 45–54 | 11.6% (27 778) | 17.7% (35 274) |
| 55–64 | 12.0% (28 701) | 19.3% (38 617) |
| 65 and older | 33.5% (80 104) | 15.2% (30 377) |
| Mean (SD) age at incident TBI | 52 (24) | 45 (17) |
| Incident TBI characteristics | ||
| Inpatient treatment | 27.0% (64 777) | – |
| Outpatient treatment | 73.0% (174 648) | – |
| Mild TBI | 28.6% (68 381) | – |
| All other TBI | 71.4% (171 044) | – |
| Polytrauma | 18.6% (44 509) | – |
| Neuropsychiatric diagnoses 12 months before incident TBI* | ||
| Substance use disorders | 3.3% (7888) | 0.7% (1302) |
| Psychotic disorders | 0.6% (1396) | 0.4% (798) |
| Mood disorders | 2.8% (6619) | 1.3% (2575) |
| Anxiety disorders | 2.5% (5987) | 1.2% (2436) |
| ADHD | 0.6% (1331) | 0.2% (485) |
| Seizures | 1.5% (3641) | 0.4% (757) |
| Neuropsychiatric diagnoses 12 months after incident TBI* | ||
| Substance use disorders | 6.2% (14 889) | 0.7% (1425) |
| Psychotic disorders | 0.7% (1652) | 0.4% (781) |
| Mood disorders | 3.4% (8033) | 1.4% (2721) |
| Anxiety disorders | 3.0% (7216) | 1.4% (2707) |
| ADHD | 0.7% (1677) | 0.3% (567) |
| Seizures | 2.7% (6334) | 0.4% (767) |
*For unaffected full siblings, age and 12-month prevalence of neuropsychiatric diagnoses were calculated from the date of their sibling’s incident TBI.
ADHD, attention-deficit hyperactivity disorder.