Medical Conditions, Mental Disorders, and Suicidal Behaviors

This post was written by Eugene Rubin MD, PhD and Charles Zorumski MD.

Suicide is one of the leading causes of death in the U.S. The Centers for Disease Control and Prevention (CDC) reports that over 49,000 Americans died by suicide in 2023, and 1.5 million attempted suicide. Are certain medical and psychiatric illnesses associated with suicide attempts and completed suicides? If so, are the associations the same for suicide attempts and completed suicides? These questions are addressed in a recent paper by Fenfen Ge and colleagues in JAMA Psychiatry.

Methods

These investigators utilized comprehensive health information contained in Danish national registers. They identified 81,713 individuals older than 10 years who made a suicide attempt and compared their health information with 408,490 age-and-sex-matched controls. They also identified 9,362 individuals who died by suicide and compared their health information with that of 46,749 age-and-sex-matched controls.

For their analysis of associations between various health conditions and suicidal behaviors, the researchers considered 28 clinically diagnosed health conditions within nine categories: mental, circulatory, endocrine, pulmonary, gastrointestinal, urogenital, musculoskeletal, cancer, and neurological. Mental disorders accounted for ten of these 28 conditions.

Medical disorders can coexist with other medical disorders. In addition, medical disorders can coexist with psychiatric disorders. How such comorbidities influence the relationships between health conditions and suicidal behaviors is not addressed in this paper.

Certain genetic markers have been associated with specific medical and psychiatric conditions and may play a role in the development of these disorders. Using another Danish dataset containing genotype information, Ge and colleagues examined associations of specific genetic markers with suicide attempts and completed suicides.

Results

Associations with non-psychiatric illnesses

All 18 medical (non-psychiatric) conditions were associated with statistically significant increased rates of suicide attempts. The increases ranged from 53% with cancer to over a 4-fold increase with epilepsy.

Most of these medical conditions were also associated with statistically significant increased rates of completed suicides. The highest increases were seen with epilepsy (almost 4-fold increase), pain states (over 3-fold increase), and chronic kidney disease (about 2.7-fold increase). No increased rate of suicide was observed for gout, diverticular disease of the intestine, and vision problems.

Associations with psychiatric illnesses

All ten psychiatric disorders were associated with increased rates of suicide attempts, and the increased rates were higher than those observed with any non-psychiatric condition. Rates of suicide attempts were elevated 4- to 10-fold in people with attention-deficit/hyperactivity disorder (ADHD), anorexia nervosa, anxiety disorders, autism spectrum disorder (ASD), and obsessive-compulsive disorder (OCD). Rates were more than 10-fold elevated in those with schizophrenia, major depressive disorder, bipolar disorder, substance use disorder, and post-traumatic stress disorder (PTSD).

Similarly, increased rates of suicide were associated with every psychiatric disorder the research team investigated. Rates were increased between 5- and 10-fold in persons with ADHD, ASD, anxiety disorder, and OCD, while rates were increased more than 10-fold in those with schizophrenia, major depressive disorder, bipolar disorder, substance use disorder, anorexia nervosa, and PTSD.

Associations with genetic markers

Ge and colleagues examined the association of 35 specific genetic markers of medical and psychiatric illnesses (25 medical, 10 psychiatric) with suicide attempts and completed suicides. They found that nine genetic markers of medical illnesses and seven markers of psychiatric illnesses were associated with increased rates of suicide attempts. In contrast, only genetic markers of bipolar disorder, schizophrenia, and major depressive disorder were associated with completed suicides.

Are certain illnesses more associated with suicide attempts than with completed suicides?

The authors developed a model to examine which disorders were more associated with suicide attempts than completed suicides and, conversely, which disorders were more associated with completed suicides than suicide attempts. With respect to medical disorders, most chronic conditions like dyslipidemia, hearing problems, and ischemic heart disease were more associated with suicide attempts whereas cancers were more associated with completed suicides.

With respect to psychiatric illnesses, major depressive disorder, anorexia nervosa, ASD, and OCD were more strongly associated with completed suicides than suicide attempts. Bipolar disorder, schizophrenia, anxiety disorder, and ADHD were equally associated with increased risk of completed suicides and suicide attempts.

Thoughts about the importance of this study

People who attempt suicide often do not intend to die but are in a crisis and need help. Many persons who commit suicide have not made previous suicide attempts and have made a conscious decision to end their lives. Despite the differences between these two groups, it is not surprising that the presence of medical and psychiatric disorders contributes to the risks of individuals becoming overwhelmed and making either a non-fatal suicide attempt or, especially in conjunction with severe illnesses like major depression, bipolar disorder, or schizophrenia, committing suicide.

Not surprisingly, many psychiatric disorders were associated with large increased rates of both suicide attempts and completed suicides in the Ge study. The work reported in this paper also quantitates the degree of increased risk from various medical disorders. This is new and clinically important information.

Health care providers should be aware that chronic and acute medical disorders, as well as psychiatric disorders, are associated with suicide attempts and completed suicides. Screening for common psychiatric disorders is important, but screening for suicidal thoughts in patients who are medically ill is also appropriate. Addressing these issues in a timely manner can save lives.

If you or someone you love is contemplating suicide, seek help immediately. For help 24/7 dial 988 for the 988 Suicide & Crisis Lifeline, or reach out to the Crisis Text Line by texting TALK to 741741. To find a therapist near you, visit the Psychology Today Therapy Directory.