Depression is a common comorbidity in amyotrophic lateral sclerosis (ALS) and has a detrimental effect on survival and quality of life, data indicate.
While depression does not appear to worsen with motor progression, it is associated with disease severity at initial assessment, researchers report. The findings were published in Neurology.
The observational study, conducted by Nimish J. Thakore, MD, DM and Erik P. Pioro, MD, PhD, both of Cleveland Clinic, explored the prevalence of depression in patients with ALS, its effect on survival, and its association with and effect on disease course.
The investigators analyzed patient-reported outcomes via a questionnaire completed by 1067 (mean age at onset =61.15 years; 44.3% female) patients with ALS between August 2006 and January 2015. The questionnaire included the Patient Health Questionnaire-9 (PHQ-9) and other self-report measures. Over the 8-year study period, 964 participants had at least one PHQ-9 recorded.
Upon initial review of PHQ-9 scores, 313 (32.5%) had moderate depression, 133 (13.8%) had moderate-severe depression, and 48 (5%) had severe depression. Antidepressant use was recorded in 52.3% of patients. Median PHQ-9 scores remained low (6 initially, mean 6.3 during follow-up). Median survival of initially depressed and nondepressed patients was 763 days and 1102 days, respectively, resulting in a difference of about 11 months (P<0.0001). Each increasing point of initial PHQ-9 score increased risk of death by 4.4% (95%CI 2.8-6; P<0.0001). Presence of major depressive disorder by DSM-IV criteria was also associated with poor survival (HR 1.56, P<0.001).
Decrease in initial ALS Functional Rating Scale-revised (ALSFRS-R) and increase in Center for Neurologic Study-Lability Scale (CNS-LS) was associated with increased odds of depression of 8% and 11%, respectively. More advanced disease and pseudobulbar affect were also associated with depression. Among those with multiple PHQ-9 scores, worsening depression was not observed.
“Our findings suggest that depression (of some degree) is prevalent in a representative outpatient population of patients with ALS, and that it exerts a robust deleterious effect on survival over and above the effect of other established and powerful predictors,” the authors wrote. “Although there is no evidence to suggest that treatment of depression improves survival, such treatment is clearly reasonable, presumably to help patients cope better as this fatal illness progresses.”