Objective. Mental disorders in patients with lateral amyotrophic sclerosis (AMS) and their family members were studied. Material and methods. Authors examined 118 AMS patients and 97 their family members. Mental status was assessed using Hamilton scale and the frontotemporal dementia scale. Results. Mental disorders were identified in 101 (85%) of AMS patients and in 51 (52.5%) of their family members. The patients had situational disorders, with a slight prevalence of situational depression. Sometimes AMS was comorbid to endogenous mental diseases. Cognitive impairment that reached the diagnostic threshold of dementia was observed in 4.2% of the patients. The family members had only situational disorders with distinct predominance (28%) of anxiety states. Common intoxications (tobacco smoking, drug addiction etc) were noted in 49 (41.5%) of AMS patients and 80 (82.4%) of their family members. Anxiety and other mental disorders often resulted in the noncompliance with physician recommendation and refusal of treatment. Conclusion. Permanent patronage of AMC families by specialists of neurologic and psychotherapeutic services and assistance based on the mental state and general medical situation are recommended.