Introduction:
There are higher rates of depression and suicidal ideation among those with chronic diseases, including end-stage renal disease, diabetes mellitus and liver disease. Suicide is the tenth leading cause of death worldwide and is more prevalent among transplant recipients. Although transplantation has the potential to improve quality of life, many transplant recipients commit suicide each year. The extent to which sex, race, age, type of insurance coverage, time on waitlist, comorbidities, immunosuppressive regimen and graft loss contribute to suicide risk in this population remains understudied.

Methods:
We queried UNOS data collected between 1990 and 2019 to determine what risk factors contribute to suicide in the transplant population. Suicide mortality rate was calculated by determining the fraction of organ recipients who died by suicide since 1990 and was expressed as deaths per 100 000. Two groups (suicide and all other cause mortality) were compared via univariate and multivariate statistical analysis. Time to graft loss was estimated using a Kaplan Meier Product Limit method. A propensity score analysis was performed to match patients who committed suicide to those who did not, allowing us to balance the relatively small sample of size of the suicide cohort with the larger all other cause mortality group to minimize the effect of confounding variables. We estimated years of organ life lost using the restricted mean. Statistical significance was defined by p < .05.

Results:
The data included 135 432 transplant deaths in total; the majority were kidney recipients-82 305 (61%). We determined suicide rates of .28%, .31%, and .44% for kidney, liver and pancreas, respectively, with an overall rate of .3%. Across all three organs the most significant risk factor was male sex. Non-Hispanic whites were also at elevated risk (OR = 2.16, p < .003). In the liver and kidney transplant groups, the odds of committing suicide were reduced by 4% with advancing age. The odds of taking one's own life was inversely related to BMI in the kidney and pancreas groups. We observed a doubling of suicide rates from .3% in 2014 to .6% in 2018. There were no other statistically significant correlations.

Conclusion:
Suicide is more prevalent among transplant recipients than in the general population. White males in particular are most at risk. The highest rate of suicide was in pancreas recipients. Advancing age and increasing BMI conferred some protective effect. There were no significant associations between suicide incidence and glucocorticoid use, type of insurance coverage, time on waitlist or graft loss. The phenomenon has become more prevalent in recent years.