Death and Suicide Ideation in Parkinson’s Disease
S. Nazem, J. Duda, A. Siderowf, G. Brown, M. Stern, D. Weintraub

Background: Depression in some form is common in Parkinson’s disease (PD), but there has been little study of death or suicide thoughts and behaviors in this population. Preliminary studies of clinical populations suggest that suicide ideation is relatively common, but analyses of administrative databases suggest that completed suicide is rare in PD. Additionally, little is known about clinical and demographic correlates of death and suicide ideation in PD.

Objective: To examine the frequency and correlates of death and suicide ideation in PD.

Methods: The study population consisted of 116 outpatients with a diagnosis of idiopathic PD. Subjects were established patients at two movement disorder centers and were evaluated as part of a study examining the frequency and correlates of depression in PD. Study participants completed the Paykel Scale for death and suicide ideation, as well as an extensive psychiatric, neuropsychological, and neurological battery.

Results: The sample was primarily male (75%), married (81%) and white (93%), with the following mean (SD) values: age= 64.7 (10.4) years, duration of PD= 7.1 (5.8) years, and educational level= 15.6 (3.2) years.

Current death and suicide ideations were present in 38% and 11% of the sample, respectively, and 4% of the population had a lifetime history of a suicide attempt. Both death ideation (χ2 [df=1]= 32.7, P<.001) and suicide ideation ((χ2 [df=1]= 6.1, P=.014) were associated with a current diagnosis of depression. Using multivariate regression models, increasing severity of depression (B [SE]= .13 [.04], P=.001) and anxiety (B [SE]= .07 [.03], P=.03) were associated with death ideation, and increasing severity of depression (B [SE]= .09 [.04], P=.05) and global cognitive impairment (B [SE]= -.43 [.22], P<.05) were associated with suicide ideation.

Conclusion: Death and suicide ideation are common in PD, but suicide attempts may not be. Comorbid psychiatric disorders and cognitive impairment, more than core PD-related factors, are associated with death and suicide ideation, highlighting the need for routine psychiatric evaluation and treatment in this population. Further study is needed to explore the apparent discrepancy between the relatively frequent occurrence of death or suicide ideation and infrequent occurrence of suicide attempts or completed suicide in PD.