Association between depression and cognitive decline in sclerosis multiplex patients

BACKGROUND: Multiple sclerosis (MS) is the most common neuroimmunological disease. In addition to its somatic symptoms, fatigue, mood disorder (depression) and cognitive impairment can be detected. Cognitive impairment significantly affects social relationships, work capacity, quality of life independently of disability. AIM: The aim of our research is to analyse the complex relationship between depression, manifestation of which occurs more often in MS compared to normal population, and cognitive functioning in multiple sclerosis. METHODS: Forty participants (sixteen men, twenty-four women) are MS patients of the Department of Neurology, Semmelweis University. Control group included forty-two age-, gender-, and education-matched subjects (sixteen men, twenty-six women). Patients were screened using MMSE; and verbal learning, visual information processing, attention, short-term and long-term memory were tested. Depression was also assessed. RESULTS: In multiple sclerosis learning, long-term verbal memory and short-term visuospatial memory were impaired compared to control group. Working memory, information processing and attention were found to be intact. Depression scores of MS patients were significantly higher than those of the normal population. Regarding the relationship between depression and cognitive impairment, negative correlation was found between mood and short-term visuospatial memory. CONCLUSION: Results of our research reflect the findings of clinical studies whereas short-term and long-term memory excluding working memory can be impaired in multiple sclerosis. Because of incidence of depression and fatigue and the important role of psychological factors in quality of life, more detailed analysis of the relationship between mood, fatigue and cognitive impairment would be required which is planned in the future.