The final cohort included 19 422 youth with FEP (see Table 1 for demographic data). 90.7% of youth had at least one psychiatric comorbidity; the most common were anxiety (56.4%) and substance use disorder (56.1%). Almost one-third had a complex, chronic medical condition (32.4%), and few had prior DSH (5.9%) or child abuse and neglect (2.3%). Median follow-up time for the cohort created to analyze DSH risk factors was 530.5 days (SD: 594.7 days IQR: 220.0–1027.0 days) and, for the cohort created to analyze suicide risk factors, 608.0 days (SD: 604.2 days; IQR: 273.0–1100.0 days).
Risk Factors for Deliberate Self-harm
Approximately 11.1% of the total cohort (n = 2148) had at least one DSH event during follow-up. The unadjusted rate of DSH was 58.2 per 1000 person-years for the entire cohort, 65.6 per 1000 person-years for adolescents, and 44.2 per 1000 person-years for young adults (Table 2). The cumulative incidence curves for first DSH for both adolescents and young adults (Figure 1) showed a sharp increase after the index psychosis diagnosis, with a more gradual rise after. The DSH hazard is high until about 3 months, after which it remains stable (supplementary figure S1). Among those with at least one DSH event during follow-up, the median follow-up time before first DSH in adolescents was 208.0 days (SD: 526.5 days; IQR: 33.0–643.0 days) and in young adults was 108.0 days (SD: 341.0 days; IQR: 10.0–377.0 days). Among adolescents, the probability of DSH is 5.3% at 3 months, 7.4% at 6 months, 9.9% at 1 year, and 22.6% at 5 years. Among young adults, the probability of DSH is 3.2% at 3 months, 4.2% at 6 months, 5.4% at 1 year, and 14.9% at 5 years. The cumulative incidence curves for first DSH were significantly different between adolescents and young adults (P < .001). Among those who had at least one DSH event during follow-up, the highest level of care on the day of the first DSH event was distributed as follows: inpatient: 43.9% (n = 942); ER: 38.5% (n = 828); outpatient: 17.6% (n = 378).
In the adjusted model (Table 2), female sex, foster care eligibility, ADHD, anxiety, disruptive behavior, personality, substance use, and other mental health disorders, presence of a complex chronic or non-complex chronic medical condition, history of child abuse and neglect, DSH, and suicidal ideation, as well as prior mental health service use were associated with increased hazards of DSH. Young adults compared to adolescents, non-Hispanic Black participants compared to non-Hispanic White, and disabled or other eligibility types compared to poverty were associated with decreased hazards of DSH. For the outcome of DSH, the following variables violated the proportional hazards assumption: Medicaid eligibility; prior suicidal ideation or DSH; index psychosis category; ADHD, disruptive disorder, intellectual disability, and other mental health disorders; and prior inpatient, emergency room, and outpatient mental healthcare. The findings were not altered by correction for multiple comparisons using the false discovery rate.
There were few differences between adolescents and young adults in risk factors for DSH (Table 3). However, female sex and disruptive behavior disorder were more strongly associated with the increased hazards of DSH in adolescents than young adults whereas substance use disorder, previous DSH or suicidal ideation, and prior emergency room mental healthcare were more strongly associated with increased hazards of DSH in young adults than adolescents. Non-Hispanic Black compared to Non-Hispanic White was more strongly associated with decreased hazards of DSH in young adults than adolescents. After adjustment for multiple comparisons using the false discovery rate, the differences between adolescents and young adults for all these variables except race/ethnicity remained statistically significant.
Risk Factors for Suicide
The suicide standardized mortality ratio (SMR) for the total cohort was 4.5 (95% CI: 2.9–6.8) compared to the same calendar year, age, and gender general population (Table 4). The suicide SMR was higher for adolescents (SMR = 5.4, 95% CI: 3.2–8.6) than for young adults (SMR = 3.2, 95% CI: 1.3–6.6). The cumulative incidence curves for suicide were not significantly different between adolescents and young adults (P-value: .40; supplementary figure S2). Among those who died by suicide, median follow-up time before suicide was 501.0 days (SD: 656.2 days; IQR: 104.0–682.5 days) for adolescents and 240.0 days (SD: 167.0 days; IQR: 190.0–435.0 days) for young adults.
In an exploratory analysis, adjusted models demonstrated increased hazards of suicide associated with personality disorders, substance use disorders, other mental health disorders, and history of DSH or suicidal ideation (supplementary table S3). For the outcome of suicide, only prior DSH and intellectual disability violated the proportional hazards assumption. After adjustment for multiple comparisons using the false discovery rate, only substance use disorders and prior DSH remained statistically significantly associated with the increased hazard of suicide.
All Causes of Death and Unintentional Deaths
The SMR for all causes of death for the combined sample was 3.8 (95% CI: 3.2–4.5) and was higher for young adults (SMR: 4.2; 95% CI 3.3–5.4) than adolescents (SMR: 3.5; 95% CI: 2.7–4.4). The SMR for unintentional death was elevated in the combined cohort in relation to the general population (SMR = 2.54, 95% CI: 1.7–3.4) and in the young adult cohort (SMR: 3.3; 95% CI: 2.1–5.0) but not among the adolescent cohort (SMR: 1.8; 95% CI: 1.0–3.0). 81.3% (n = 26) of unintentional deaths were due to accidental poisoning, while 18.8% (n = 6) were due to other causes, such as accidental drowning, transport accidents, or accidental hanging/strangulation.
Schizophr Bull. 2022;48(2):414-424. © 2022 Oxford University Press