The clinical correlates of suicidal ideation in Parkinson's disease

Introduction: Suicidal ideation is increased in Parkinson's disease (PD) patients. The possible relationship between parkinsonian motor and non-motor symptoms and suicidal ideation in PD is unknown. The aim of the study was to evaluate suicidal ideation in patients with PD in a controlled study specifically designed to identify the clinical correlates of PD suicidal ideation.

Methods: We consecutively enrolled 100 patients with PD, 76 patients with psoriasis and 80 healthy subjects. Motor symptoms and complications were evaluated by using the International Parkinson and Movement Disorder Society-Unified Parkinson's Disease Rating Scale. Non-motor symptoms were evaluated by means of the Non-Motor Symptoms assessment scale for PD. All patients also underwent a psychiatric evaluation that included the administration of the Columbia-Suicide Severity Rating Scale.

Results: Suicidal ideation was present in 31% of PD patients, 16% of patients with psoriasis and 2% of healthy controls. PD patients showing suicidal ideation have more frequent motor complications, more severe non-motor symptoms and a higher perceived disability than patients without suicidal ideation. Suicidal ideation correlated with the presence of motor complications as well as with non-motor symptom severity, perceived disability severity and the presence of psychiatric disorders.

Conclusions: Our findings showed that suicidal ideation is increased in PD patients compared with healthy controls and patients with psoriasis and that several clinical PD features, including motor complications and non-motor symptoms, are associated with suicidal ideation in PD. The results suggest a multi-factorial origin of PD suicidal ideation.