Objective: We aimed to determine suicide risk and lifetime suicidal ideation in Parkinson disease (PD) patients versus controls and how depression, demoralization, and insomnia are associated with suicidality.
Methods: In this case-control study, PD patients and matched controls were recruited from movement disorder clinics, Michael J. Fox Foundation, and Research Match websites. Suicide risk and suicidal ideation were assessed using the Suicidal Behavior Questionnaire-revised (SBQ-R) and Columbia-Suicide Severity Rating Scale. Lifetime depression was assessed using the Brief Lifetime Depression Scale, sleep using Insomnia Severity Index (ISI), demoralization using Diagnostic Criteria for Psychosomatic Research and Kissane Demoralization Scales, and non-motor symptoms using UPDRS Non-Motor Aspects of Experiences of Daily Living scale (nM-EDL).
Results: 186 PD participants and 177 controls were matched for age (64.2 ± 7.7 years), sex (48.8% female), and socioeconomics. PD participants were not more likely than controls to have high suicide risk (SBQ-R ≥ 7) (7.5% vs. 11.3%; p = 0.22) or to have had a lifetime suicide plan or attempt (2.7% vs. 5.1%; p = 0.24), but were less likely to have had lifetime suicidal ideation (23.1% vs. 35.0%; p = 0.01). PD participants were more likely than controls to have lifetime depression history (34.4% vs. 20.9%; p = 0.004), and demoralization (19.9% vs. 10.7%; p = 0.02), and had higher ISI scores (8.7 ± 5.8 vs. 5.1 ± 4.5; p < 0.0001). PD patients with high versus normal suicide risk had higher nM-EDL scores (16.5 ± 6.8 vs. 10.7 ± 5.9; p = 0.002), and more demoralization (71.4% vs. 21.5%; p < 0.0001).
Conclusions: Suicide risk is not elevated and suicidal ideation is uncommon in PD, despite the high prevalence of depression and demoralization.
Keywords: Demoralization; Depression; PD; Parkinson disease; Suicidal ideation; Suicide.