Association between new-onset Parkinson’s disease and suicide risk in South Korea: a nationwide cohort study

Abstract

Background Parkinson’s disease (PD) is an increasingly common neurodegenerative disease in an aging society. Whether PD is associated with an increased suicide risk is unclear. Thus, we investigated the effect of new-onset PD on suicide. Methods Using the National Health Insurance Service Senior Sample Cohort of South Korea, 17,143 incident PD patients and 17,143 risk set controls, matched by propensity score, were selected for follow-up. The incidence rate of suicide and 95% confidence interval (CI) were calculated based on a generalized linear model of the Poisson distribution. Effect sizes were expressed as hazard ratios (HRs) using the Cox proportional hazards model with a robust variance estimator that incorporated clustering within matched pairs. Results The incidence rate of suicide was 206.7 cases per 100,000 person-years (95% CI, 172.8–246.9) among the PD cohort. Compared to the matched controls, patients with PD were 2.64 times (HR, 2.64; 95% CI, 1.31–5.30) more likely to commit suicide during the first 180 days of follow-up and 2.47 times (HR, 2.47; 95% CI, 1.42–4.28) within the first 365 days of follow-up. During the entire follow-up period, patients with PD were 2.26 times more likely to commit suicide than were their matched controls (HR, 2.26; 95% CI, 1.67–3.06). Conclusion Our findings indicated an increased risk of suicide in patients with new-onset PD, regardless of the period after diagnosis. Incorporating mental health care with social and environmental interventions into primary care and PD-specialized care can help reduce suicide risk in people with PD, improving suicide prevention, identification, and risk assessment.

Frequency of Depression among Patients with Parkinson Disease

“…20 The study revealed that a significant proportion (33%) of participants had a past experience of suicidal thoughts, indicating the necessity of screening Parkinson's disease patients for such tendencies and offering appropriate interventions. This finding is in line with a previous study that demonstrated a heightened risk of suicide in PD patients (Jeong et al, 2022). 21 Additionally, Khakimova's study suggested that as PD advances, the occurrence of hypertension may decrease, although only a minor percentage (4%) of individuals in the current research reported a history of high blood pressure.…”

Suicidal ideation among people with Parkinson's disease and comparison with a control group

“…The results regarding suicide rate when compared with controls contradicts the literature 8,10,11,14,36 . Nonetheless, more case‐control studies conducted in a large population followed for a long period of time are needed to obtain reliable conclusions 8,10,37 …”

“…In a recent extensive review about suicide in PD, 14 Shepard et al. concluded that depression is nearly invariably associated with SI and suicide attempts in relevant publications 9,31–33,37,40,41 with only one study failing to find an association, 37 even to the point that SI has been found to be a valid marker of PD depression.…”

“…8,10,11,14,36 Nonetheless, more case-control studies conducted in a large population followed for a long period of time are needed to obtain reliable conclusions. 8,10,37 Some studies have analyzed the clinical correlates of SI in PD. 11,14,29 Factors previously reported to be associated with SI are a younger age, motor complications, psychiatric disturbances including major depression, anxiety and psychosis, impulse control disorders, a greater non-motor symptoms burden, sleep problems, fatigue, sexual dysfunction, and a higher perceived disability.…”

“…Moreover, major depression was a critical factor in our analysis increasing the probability of having SI by more than 4-fold regardless of other factors. In a recent extensive review about suicide in PD, 14 Shepard et al concluded that depression is nearly invariably associated with SI and suicide attempts in relevant publications 9,[31][32][33]37,40,41 with only one study failing to find an association, 37 even to the point that SI has been found to be a valid marker of PD depression.…”