People with Parkinson's disease had twice the average risk of a suicide attempt or death by suicide, a meta-analysis showed.
Across 10 studies, the odds of suicidal behavior were 2.15-fold higher (95% CI 1.22-3.78, P=0.01) among Parkinson's patients compared with general population controls, according to Eng-King Tan, MD, of Duke-NUS Medical School in Singapore, and co-authors.
While the prevalence of suicidal behavior among Parkinson's patients was 1.25% (95% CI 0.64-2.41), about one in five people with Parkinson's had suicidal ideation (prevalence 22.2% in 14 studies, 95% CI 14.6-32.3), the researchers reported in .
Suicidality ranges from suicidal ideation (an active or passive desire for death) to suicidal behavior (a suicide attempt or death by suicide).
"Suicidality can be difficult to detect in patients with Parkinson's disease and is frequently missed even in those on long-term follow-up," Tan and colleagues wrote. "When recognized, suicidality tends to be severe with either active ideation or even suicide attempts."
"Numerous barriers prevent patients from reaching out and getting the help they need, such as stigma toward receiving mental health care, lack of knowledge, limited accessibility, and financial or logistical issues," they continued. "As such, a treatment gap exists that requires much effort to reduce."
The study showed "compelling findings regarding suicide ideation and behavior, which ought to motivate healthcare staff to be attentive towards patients diagnosed with Parkinson's disease," noted Annette Erlangsen, PhD, of the Danish Research Institute for Suicide Prevention in Copenhagen, Denmark, who wasn't involved with the meta-analysis.
Recent research led by Erlangsen showed that over a 37-year period in Denmark, people with a neurologic disorder were nearly twice as likely to die by suicide than others.
"Although we did not examine it specifically for Parkinson's disease, the findings from our study published in in 2020 revealed that the suicide rate is highest during first months after being diagnosed with a neurological disorder," Erlangsen told ѻý.
For their study, Tan and co-authors searched databases for studies about Parkinson's and suicidal ideation or suicidal behavior published through June 2023, including cross-sectional, case-control, and cohort studies. Studies that reported only on Parkinson's patients after deep brain stimulation were excluded.
The final analysis included 505,950 Parkinson's patients across 28 studies. For meta-analyses with high heterogeneity, the researchers performed influence analyses to identify outliers.
Overall, 14 studies evaluated the prevalence of suicidal ideation, and 21 studies assessed suicidal behavior. Sensitivity analyses excluding three outliers showed that the prevalence of suicidal ideation was 24%. After four outliers were removed, the prevalence of suicidal behavior was higher in prospective studies (1.75%) than in retrospective studies (0.50%).
The hazard ratio of suicidal behavior, assessed across nine studies, was 1.73 (95% CI 1.40-2.14, P<0.001) compared with controls.
Patients with Parkinson's often have psychiatric comorbidities, most prominently depression, Tan and colleagues pointed out.
"Depressive mood disorders are the greatest risk factors for both suicidal ideation and suicidal behavior and are present in almost half of patients with Parkinson's disease," they observed. "Additional risk factors include sleep disorders and feelings of hopelessness."
"Efforts directed at identifying and addressing these risk factors, such as improving the quality and quantity of sleep through medications, could be helpful for these patients," they added.
The study had several limitations, the researchers acknowledged. Heterogeneity in study design, geographic variation, and patient demographics were factors, which the researchers mitigated somewhat by identifying outliers. Suicide terminology also changed over time, resulting in "unavoidable variability in the definitions of suicidal ideation and behavior used in the included studies," they noted.
In addition, many prospective cross-sectional studies did not account for suicide deaths, potentially underestimating the prevalence of suicidal behavior.
Disclosures
Tan reported support by the National Medical Research Council and, outside the submitted work, honoraria from Eisai and Elsevier. No other disclosures were reported.
Primary Source
JAMA Neurology
Shengting Mai A, et al "Risk of suicidal ideation and behavior in individuals with Parkinson disease: A systematic review and meta-analysis" JAMA Neurol 2023; DOI: 10.1001/jamaneurol.2023.4207.