Young Adults With Schizophrenia More Likely to Commit Suicide

Adults with schizophrenia, particularly young adults, have a significantly higher suicide rate compared with the U.S. general population, according to a retrospective longitudinal cohort study.

The rate of suicide per 100,000 person-years among schizophrenic adults was 74.0, which is 4.5 times higher than the rate for the general population (standardized mortality ratio [SMR] 4.54, 95% CI 4.35-4.73). Suicide risk was highest among the youngest group of adults — ages 18 to 34 — with a suicide rate of 141.95 (SMR 10.19, 95% CI 9.29-11.18), reported Mark Olfson, MD, MPH, of Columbia University in New York City, and colleagues.

As age progressed, suicide rates decreased, with a rate of 24.01 among people age 65 and older (SMR 1.53, 95% CI 1.32-1.77), they noted in JAMA Psychiatry.

“Some possible explanations for the decline in risk with advancing age include functional recovery, learned adaptations to living with symptoms, stabilization of symptoms, or even gradual improvement among some older adults with schizophrenia,” Olfson and co-authors wrote.

A substantially smaller number of those from the oldest age group had “prior-year mental health hospital admissions, mental health emergency department visits, clinical diagnosis of suicidal ideation, or suicide attempt or self-injury compared with the youngest group,” they added.

For the youngest age group, suicide risk was associated with prior-year comorbid drug use disorders, suicidal ideation, and previous attempts at suicide or self-injury.

The study analyzed five national retrospective longitudinal cohorts of patients with schizophrenia in the Medicare program from January 2007 to December 2016 who were split up by age groups — 18 to 34, 35 to 44, 45 to 54, 55 to 64, and 65 and older.

The total cohort included 668,836 patients with schizophrenia (52.5% men), 2,997,308 years of follow-up, and 2,218 suicide deaths. The National Death Index was used to obtain death record information.

Breaking it down by sex, Olfson and colleagues found that the suicide rate for men with schizophrenia was 88.96 per 100,000 person-years, which was 3.4 times higher than the general population (SMR 3.39, 95% CI 3.22-3.57), and was 56.33 per 100,000 person-years for women with schizophrenia, which was 8.2 times higher (SMR 8.16, 95% CI 7.60-8.75). Of note, the suicide rate was significantly higher among men with schizophrenia compared with their female counterparts, with an adjusted HR of 1.44 (95% CI 1.29-1.61).

The adjusted HRs of suicide risk were lower for Black (aHR 0.29, 95% CI 0.24-0.35) and Hispanic patients (aHR 0.66, 95% CI 0.54-0.80) compared with white patients.

“Although cultural explanations have stressed the role of religion in lowering suicide acceptability, suicide acceptability does not appear to be lower among young Black people vs young white people,” Olfson and team noted.

The suicide rate also climbed among schizophrenic patients who struggled with other mental health issues and diagnoses, such as depression (aHR 1.32, 95% CI 1.17-1.50), drug use (aHR 1.55, 95% CI 1.36-1.76), sleep disorders (aHR 1.22, 95% CI 1.07-1.39), prior suicidal ideation (aHR 1.41, 95% CI 1.22-1.63), or previous suicide attempts or self-harm (aHR 2.48, 95% CI 2.06-2.98).

The study’s major limitation, the authors noted, was the inability to verify the various diagnoses and events recorded in the Medicare data that were analyzed. Although they used a validated case identification algorithm, there was no way to measure the accuracy of individual schizophrenia diagnoses, causes of death, or other diagnoses through Medicare claims data.

“Although much remains unknown about why suicide risk declines in schizophrenia across the life span, several risk factors — including suicidal ideation, suicide attempt or self-injury, comorbid drug use diagnoses, and mental health inpatient admissions and emergency department visits — also decline with advancing age,” Olfson and colleagues wrote.

“Nevertheless, high suicide risk in young adults with schizophrenia supports clinical vigilance in this patient population, with particular attention to patients with prior suicide attempts or self-injury, suicidal ideation, and comorbid substance use disorders,” they added.