Volume 23 Issue 11, Pages 1573-1579 (15 August 2008)
Published Online: 10 July 2008
Authors: Sarra Nazem, BA, Andrew D. Siderowf, MD, John E. Duda, MD, Gregory K. Brown, PhD , Tom Ten Have, PhD, Matthew B. Stern, MD, Daniel Weintraub, MD
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Parkinson's disease (PD) is a chronic, disabling illness affecting primarily the elderly and is associated with a high prevalence of depression. Although these are known risk factors for suicidal and death ideation, little is known about the prevalence and correlates of such ideation in PD. A convenience sample of 116 outpatients with idiopathic PD at two movement disorders centers were administered a modified Paykel Scale for suicidal and death ideation, as well as an extensive psychiatric, neuropsychological, and neurological battery. Univariate and multivariate logistic regression models were used to determine the correlates of suicidal or death ideation. Current death ideation (28%) or suicide ideation (11%) were present in 30% of the sample, and 4% had a lifetime suicide attempt. On univariate logistic regression analysis, increasing severity of depression (odds ratio = 2.92, 95% CI 2.01-4.24, P < 0.001), impulse control disorder (ICD) behaviors sometime during PD (odds ratio = 6.08, 95% CI 1.90-19.49, P = 0.002), and psychosis (odds ratio = 2.45, 95% CI 1.05-5.69, P = 0.04) were associated with either ideation. On multivariate logistic regression analysis, only increasing severity of depressive symptoms (odds ratio = 2.76, 95% CI 1.88-4.07, P < 0.001) predicted suicidal or death ideation. In conclusion, active suicidal or death ideation occurs in up to one-third of PD patients. Comorbid psychiatric disorders, more than PD-related disease variables, are associated with this ideation, highlighting the need for a comprehensive approach to the clinical care of PD patients.
© 2008 Movement Disorder Society
Podcast summary and review by Dr. Laura Marsh, MD Associate Professor, Psychiatry and Neurology Johns Hopkins University School of Medicine
Despite high rates of depressive symptoms and depressive disorders in idiopathic Parkinson's disease (PD), suicidal thoughts and behaviors have traditionally been regarded as less common relative to the general population. Recent reports of an increased suicide risk associated with subthalamic nucleus deep-brain stimulation (DBS) in patients with advanced PD call attention to the need for systematic inquiry into the scope and risk factors of suicidality in patients with PD.This study investigated the prevalence and correlates of death ideation and suicide-related thoughts and behaviors, which include thoughts about ending one's life intentionally, suicide attempts, and completed suicides. Death ideation is defined as the wish to die without intent to kill oneself. The study sample included 116 outpatients with idiopathic PD attending tertiary care movement disorder clinics and globally intact cognitive status based on the mean Mini-mental State Exam score (28.6). The Paykel Scale was used to self-report presence of suicidal ideation (SI) and death ideation (DI) over the last month and lifetime suicide attempts. Subjects also underwent a diagnostic psychiatric evaluation and assessments of demographic features, a range of psychiatric symptoms, and parkinsonian motor deficits. Participants (75% male, 93% Caucasian) had a mean (SD) age of 64.7 (10.4) years and, on average, a 7-year duration of PD that was mild to moderate in severity. Major depression was diagnosed in 27.6% and non-major depression (minor depression or dysthymia) in 10.3%.
In this study, 30% (n=35) of the sample experienced either current SI or DI, with 28% endorsing SI and 11% reporting DI. 10% experienced both SI and DI. Only 5 subjects (4%) reported a prior suicide attempt. As might be expected, the presence of major depression and more severe depressive symptoms (based on the rater-administered Inventory of Depressive Symptomatology scale) were associated with SI and DI. However, psychosis and a history of impulse control disorder behaviors since onset of PD also predicted SI and DI; 89% of patients with SI or DI had either a depression diagnosis, psychosis, or an ICD behavior at some point. By contrast, PD-related variables and demographic features were not associated with SI or DI.
While this study lacks a control population, the presence of active suicidal and morbid thoughts in nearly one-third of PD patients is relatively high compared to other studies in the elderly and probably comes as a surprise to many clinicians caring for patients with PD. As such, the study provides another reminder of the impact of depressive and other psychiatric disturbances in PD and the importance of multidisciplinary care that attends to the motor and psychiatric aspects of the disease. Often, untreated psychiatric disorders, more than motor symptoms, drive subjective distress and disability. This is particularly the case for depressive disorders, which tend to be under-recognized and under-treated in patients with PD. Though suicide attempts are uncommon in PD, an association of psychotic symptoms and impulsive behaviors with SI and DI is concerning given their potential effects on judgment and behavior.
Suicide is a devastating public health problem, ranking 11th among causes of death in the United States. There is no evidence that asking about suicidality and DI provokes suicidal behaviors. For clinicians not trained in mental health, such an inquiry can seem daunting or intrusive. One approach for beginning the discussion is to 'normalize' the possible experience, e.g., by saying "Not that you should feel this way, but sometimes people begin to think that their life is not worth living, or they might think of hurting themselves or taking their life --- have you been having such thoughts?" However, determination of actual suicide risk in a given individual requires direct questions about SI and suicidal plans along with evaluation of other risk and protective factors. In general, presence of any psychiatric illness, especially a depressive disorder, availability of lethal means, a prior suicide attempt, hopelessness, and ambivalence are 'red flags.' There should be a low threshold for psychiatric consultation. Further research is needed to identify specific risk factors for suicidality in patients with PD. Additional information on suicide prevention can be found on the websites for the Suicide Prevention Resource Center and the American Foundation of Suicide Prevention.
About Dr. Laura Marsh, MD
Dr. Marsh is an Associate Professor of Psychiatry and Neurology at Johns Hopkins University School of Medicine where she is also the Principal Investigator of the Clinical Research Core of the Johns Hopkins/NIH Morris K. Udall Parkinson's Disease Research Center of Excellence. Dr. Marsh, a geriatric psychiatrist, has participated on Movement Disorder Society Task Forces to evaluate psychiatric rating scales in Parkinson's disease and is a member of Scientific Review Committees for the American Parkinson's Disease Association and the Parkinson's Study Group. Her research focuses on improving the recognition and treatment of cognitive and psychiatric disturbances in patients with Parkinson's disease. She is the Principal Investigator of an NIH-funded study on methods of optimal depression detection in Parkinson's disease (the MOOD-PD Study).