Late-Life Suicide in Terminal Cancer: A Rational Act or Underdiagnosed Depression?

Previous studies have reported significantly elevated standardized mortality rates in older people with cancer. Terminally ill people represent a unique group where suicide may be considered as rational.

The aims of this study are to compare the sociodemographic and clinical characteristics of older people with and without terminal cancer who died by suicide and analyze the suicide motives of those with terminal cancer to determine whether they represent rational suicide.

The New Zealand Coronial Services provided records of all older people (aged 65 years and older) who died by suicide between July 2007 and December 2012. Sociodemographic and clinical data were extracted from the records. Using the characteristics for defining rational suicide, we determined whether the motives in terminal cancer cases represented rational suicide.

Of the 214 suicide cases, 23 (10.7%) older people were diagnosed with a terminal cancer. Univariate analysis found that older people with terminal cancer who died by suicide were less likely to have a diagnosis of depression (8.7% vs. 46.6%; P = 0.001) or previous contact with mental health services (4.5% vs. 35.0%; P = 0.004) than those without terminal cancer. About 82.6% of the terminal cancer cases had a motivational basis that would be understandable to uninvolved observers.

A high proportion of those with terminal cancer had motives suggestive of rational suicide. Future studies are needed to clarify whether the low rate of depression is secondary to underdiagnosis of depression or people with terminal cancer choosing to end their life as a rational act to alleviate suffering.