Survival in Amyotrophic Lateral Sclerosis The Role of Psychological Factors

OBJECTIVE Examining the relationship between psychological status and survival in amyotrophic lateral sclerosis. Our hypothesis is that psychological distress is associated with greater mortality and shorter survival time than psychological well-being. DESIGN Cross-sectional, longitudinal. The baseline evaluations used were disease severity and 10 psychometric tests. A psychological status score was derived from these tests. Survival status was monitored for 3.5 years. Interviewers were blinded to other interviews and data analysis. SETTING Patient's residence. PATIENTS The criteria for eligibility were diagnosis of amyotrophic lateral sclerosis by a neurologist, dementia or alcoholism absent, communication in English, and any severity or length of disease. It was a volunteer sample consisting of 144 patients from amyotrophic lateral sclerosis clinics or community-based amyotrophic lateral sclerosis support groups. In this sample 66% were men, 94% were white, mean age at diagnosis was 55 years, 79% were married, 60% had some college education, and 61% died during the study. INTERVENTIONS None. MAIN OUTCOME MEASURES END POINTS mortality during study, survival time from intake to last follow-up. RESULTS Comparison between high and low psychological score groups: 32% of high and 82% of low died; survival curves were significantly different. Controlling for confounding factors (length of illness, disease severity, age), patients with psychological distress had a greater risk of mortality (relative risk, 6.76; 95% confidence limits, 1.69 to 27.12) and greater likelihood of dying in any given time period (relative risk, 2.24; 95% confidence limits, 1.08 to 4.64) than those with psychological well-being. CONCLUSION Adjusting for confounding factors, psychological status is strongly related to outcome in amyotrophic lateral sclerosis. Further studies on psychological status should be done to confirm its prognostic value.