Suicidal Thoughts Not Uncommon in MS, Epilepsy Patients

By Adele C. Viguera, MD, MPH

Patients with epilepsy and multiple sclerosis (MS) show high rates of depression and an increased risk for suicide. They also are more likely to think about death and self-harm than are individuals with other chronic illnesses, such as arthritis or cancer, according to a study of suicidal ideation conducted by Cleveland Clinic.

Major depressive disorder (MDD) affects 20 to 50 percent of patients with epilepsy, MS, Parkinson disease or dementia. Depression adds to their disease burden, and suicide contributes substantially to excess mortality in this population.

Increased Suicide Risk in Epilepsy and MS Patients

Suicide risk is eight times greater in epilepsy patients, compared with the general U.S. population. Identified risk factors include co-occurring psychiatric illness (especially MDD), female gender, older age and early epilepsy onset or recent diagnosis. Similarly, suicide risk may be 1.8 to 7.5 times higher in MS patients. Risk factors include co-occurring psychiatric disorders, male gender and early-onset MS.

Suicidal ideation is reported by individuals with many chronic medical conditions ‒ such as 5 percent of arthritis patients and 8 percent of cancer patients, compared with 2.8 to 3.3 percent of the general population. Although epilepsy and MS patients have high suicide rates, surprisingly little is known about how often they think about self-harm.

Retrospective Study Analyzes Suicidal Ideation Prevalence

Given these high rates, and to contribute to existing evidence, our group designed a nearly five-year retrospective analysis of the prevalence of suicidal ideation in patients seen at Cleveland Clinic’s epilepsy and multiple sclerosis centers. As part of Cleveland Clinic’s Knowledge Program ‒ an initiative to compile discrete electronic clinical information for research, patient care improvement and quality measures ‒ these centers systematically collect data from patient-entered, validated measures of health status and outcomes, including the Patient Health Questionnaire-9 (PHQ-9) screen for depression and the EQ-5D™ European quality-of-life scale.

The PHQ-9 is intended to detect psychiatric symptoms of depression. It rates nine questions related to depression by frequency, from 0 to 3, with a 10th item to indicate overall severity. A total score of 10 to 14 indicates mild to moderate depression, 15 to 19 moderate to moderately severe depression and ≥ 20 severe depression.

Item 9 of the questionnaire addresses the presence and persistence of recent thoughts of death or self-harm. Although there are high rates of false-positive results, this simple method has proved useful in screening for suicidal risk in primary care medical settings. Few patients identified by their PHQ item 9 responses later attempt suicide, but there is a significant association. A recent large retrospective study found that risks of attempted and completed suicide were 10 times greater among patients reporting elevated PHQ item 9 scores and increased with persistence of the elevated scores. In clinical samples with high rates of depression, PHQ item 9 can guide selection of patients who require closer assessment and who might benefit from psychiatric care.

Our study included all patients age 18 and older evaluated at the study sites between October 1, 2007, and August 13, 2012. The primary outcome measure was response to item 9 of the PHQ-9: “How often in the past 2 weeks have you thought you would be better off dead, or of hurting yourself in some way?” We considered PHQ item 9 scores ≥ 1 to be positive for putative suicidal ideation. A score of ≥ 10 on the other eight items (PHQ-8) was used to identify probable clinical depression.

We also extracted sociodemographic and clinical information from the Knowledge Program database, including age, gender, race, marital status, approximate household income and common medical diagnoses. Neurologic disease-specific measures included ratings with the Liverpool Seizure Severity Scale for epilepsy patients and the Multiple Sclerosis Performance Scales for MS patients.

Figure 1. Relative effect of depression on PHQ item 9 response increases as MS severity worsens and depends on marital status; higher MSPS scores indicate more severe disease. SI = Suicidal ideation; MSPS = Multiple Sclerosis Performance Scales.

Suicidal ideation is reported by individuals with many chronic medical conditions ‒ such as 5 percent of arthritis patients and 8 percent of cancer patients, compared with 2.8 to 3.3 percent of the general population. Although epilepsy and MS patients have high suicide rates, surprisingly little is known about how often they think about self-harm.

Results Show High Depression, Suicide Ideation Rates

Our findings are based on 20,734 outpatient clinic visits by 2,763 patients diagnosed with epilepsy and 3,823 patients diagnosed with MS who completed the PHQ-9 at least once.

Statistical analysis showed a high rate of depression among epilepsy patients (37 percent) and MS patients (40 percent). Overall, 14.4 percent reported thoughts of death or self-harm in the prior two weeks. As expected, patients with depression were more likely to report suicidal ideation.

Among epilepsy patients, 14 percent reported thoughts of death or self-harm. Male gender was associated with putative suicidal ideation, but other demographic factors were not. Among MS patients, 14.7 percent reported thoughts of death or self-harm. Risk factors included male gender, Caucasian race, co-occurring medical disorders and lower health-related quality-of-life scores.

Figure 2. Relative effect of depression on PHQ item 9 response increases as QOL improves; in both groups, odds of positive item 9 decline as QOL improves; higher EQ-5D scores indicate better QOL. QOL = quality of life.

Suicidal ideation is difficult to quantify. Patient self-reports are based on subjective mental states that cannot be verified objectively. As stated previously, elevated PHQ item 9 scores have been associated with increased risk of suicidal behavior but almost certainly overestimate clinically significant suicide risk ‒ or even the presence of suicidal ideation. Similarly, the clinical utility of suicidal ideation as a predictor of suicide risk is severely limited. The ratio of estimated rates of suicidal ideation to suicidal behaviors may be as high as several hundred to one.

Screening Tool and Intervention

Despite this study’s limitations, we demonstrated that the PHQ-9 can be useful as a screening tool to identify neurological patients who need additional clinical assessment for depression and potential suicide risk.

Cleveland Clinic’s epilepsy and multiple sclerosis centers have specific protocols for patients who report thoughts of death or self-harm. A combination of the PHQ-9 total score, item 9 response and the clinician’s assessment is used to determine whether a patient requires transfer to the emergency department for further psychiatric assessment.

Dr. Viguera is Director of Cleveland Clinic’s Women’s Mental Health Program and is a staff member in the Department of Psychiatry and Psychology, the Center for Outcomes Research and Evaluation, and the Center for Behavioral Health. She also is an assistant professor at Cleveland Clinic Lerner College of Medicine.