Interaction of physical function, quality of life and depression in Amyotrophic lateral sclerosis: characterization of a large patient cohort

BACKGROUND: Due to lack of any curative therapy for ALS, symptomatic treatment and maintenance of quality of life (QoL) is very important. We aimed to characterize the affected domains of QoL in ALS patients and to identify factors which are associated with reduced QoL and increased depression. METHODS: 159 ALS patients answered standardized questionnaires (Beck Depression Inventory-II, SF-36 Health Survey questionnaire, revised ALS functional rating scale). Multiple regression analysis was used to identify correlations between clinical features of ALS patients and depression/QoL scores. In addition, QoL data from ALS patients were compared to age-matched reference values representing the German normal population. RESULTS: QoL of ALS patients was reduced in nearly all SF-36-categories. Progression of physical impairment was positively correlated with depression but reduced QoL scores only in items directly related to physical function. However, QoL was considerably influenced by depression, independently from physical impairment. Regarding distinct patient characteristics one of the most interesting findings was that increasing age was correlated with significantly worse QoL results regarding social functioning. CONCLUSIONS: Depressive symptoms had a strong influence on QoL, hence their detection and treatment is of particular importance. Different domains of QoL are differently affected in subgroups of ALS patients. Being aware of these differences can be valuable for both ALS professional and family caregivers and physicians. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12883-015-0340-2) contains supplementary material, which is available to authorized users.