Medical Conditions Increase Suicide Risk in a Dose-Response Manner

There is a dose-response relationship between the disability burden associated with medical conditions and suicide risk, according to study results published in JAMA Psychiatry.

Previous studies investigating the relationship between suicide and diagnosed medical conditions have focused on a limited number of medical conditions and have failed to consider co-occurring medical conditions. The aim of the current study was to estimate suicide risk across a comprehensive list of medical conditions and to determine if the risk of suicide with medical conditions differs based on a prior psychiatric disorder diagnosis.

Investigators conducted an observational cohort study using population-based data from multiple Danish registers. The investigators identified deaths attributable to suicide by searching the Danish Register of Causes of Death for International Classification of Diseases, Tenth Revision (ICD-10) codes associated with suicide. They identified medical conditions from either 1) hospital or clinic diagnoses and 2) prescription records for disease-specific medications. Additionally, information about mental disorders was found in the Danish Psychiatric Central Research Register.

The investigators evaluated 31 specific medical conditions within 9 broad categories: circulatory system, endocrine system, pulmonary system and allergy, gastrointestinal system, urogenital system, musculoskeletal system, hematological system, neurological system, and cancers. Analyses for each medical condition were carried out separately through matched cohort designs. Poisson models were used to evaluate the relationship between disability burden score and subsequent rate of suicide.  

Overall, data from 6,635,857 individuals (50.3% women) between 2000 and 2020 were included in the analyses. A total of 12,876 suicides occurred during the study period. The investigators found that the absolute risk of suicide was largely driven by psychiatric disorders and was substantially higher among men, relative to women.

When stratified by medical condition category, suicide risk was highest for gastrointestinal conditions (incidence rate ratio [IRR], 1.7; 95% CI, 1.5-1.8), cancer (IRR, 1.5; 95% CI, 1.4-1.6), and hematological conditions (IRR, 1.5; 95% CI, 1.3-1.6). Overall, suicide risk was generally higher among individuals with a medical condition vs those without a medical condition. The only medical category not associated with a significantly higher risk of suicide was endocrine disorders.

For individuals without a mental disorder, the risk of suicide increased with increasing disability burden in a dose-response-like manner; however, among those with a mental disorder, the high risk of suicide was largely driven by psychiatric status and not by disability burden from comorbid medical conditions.

These findings indicate that suicide risk is significantly elevated among those with a medical condition. “From a clinical perspective, the results of this study underscore that there should be awareness of the risk of suicide not only among individuals with severe mental disorder but also for those with certain medical morbidities,” the investigators concluded.

Study limitations include the reliance on register data and the inclusion of only Danish participants.

This article originally appeared on Psychiatry Advisor