Comparative Assessment of Psychiatric Comorbidity, Substance Use, Quality of Life in Patients With Early and Late Onset Dementia

Abstract

According to the definition provided by the World Health Organization (WHO, 2017), dementia is "an umbrella term for several diseases affecting memory, other cognitive abilities and behaviour that interfere significantly with the ability to maintain daily living activities. Although age is its strongest known risk factor, dementia is not a normal part of aging". The associated brain diseases can cause a long-term, often gradual decrease in cognitive abilities, "emotional problems, language difficulties and decreased motivation". The definition provided by the U.S. National Institute of Neurological Disorders and Stroke (NINDS, 2018) is more detailed in stating that dementia is "a group of symptoms caused by disorders that affect the brain. It is not a specific disease" and "memory loss is a common symptom of dementia. However, memory loss by itself does not mean having dementia. People with dementia have serious problems with two or more brain functions, such as memory and language. Although dementia is common in very elderly people, it is not part of normal aging. 1 Many different diseases can cause dementia, including Alzheimer disease (AD), frontotemporal dementia (FTD), Lewy body dementia (LBD), vascular dementia (VD), syphilitic dementia (SD), mixed dementia (MD), senility dementia (SD), or the combined effect of two or more dementia types, and even stroke. About 10% of individuals present with Mixed Dementia, a usual combination of AD and another type of dementia such as FTD or VD. However, not being a specific disease, the above potential contributors do not reach to the primary cause of the disease.