Difference Between Dementia and Psychosis

Dementia vs Psychosis

Dementia and psychosis are two psychiatric conditions that interfere with normal functionality of the individual. While these two terms are often heard in the study of psychiatry and psychology, it is important to understand that these two are two completely different entities affecting different parts of the psyche.


Dementia is characterized by abnormal deterioration of all cognitive functions beyond what is possible due to normal ageing. Dementia is a blanket term which refers to a progressive or a static group of symptoms and signs which is thought to be due to the progressive degeneration of the cerebral cortex. The cerebral cortex is a part of the brain that is situated outermost, and it governs all the higher brain functions. Dementia refers to a disturbance of learning, thinking, memory, behavior, speech and control of emotions.

Dementia is a common disease among the elderly and statistics suggest that an astounding 5% of the global population above 65 is affected. 1% of people below 65, 8% of people between 65 and 74, 20% of people between 74 and 84 and 50% of people above 85 suffer from dementia. There are 5 main types of dementia. Fixed cognitive impairment is a type of dementia that does not progress in severity. It results from organic brain damage; vascular dementia is a good example. Slowly progressive dementia starts out as a mere inconvenience and ends up at a stage where activities of daily living are affected. This is thought to be due to progressive disorders of the brain. Semantic dementia is characterized by loss of word and speech meaning. Diffuse Lewy body dementia progresses similar to Alzheimer’s disease but has Lewy bodies in the brain. Rapidly progressive dementia worsens in mere months as the name suggests.

Treating any primary disorder, treating superimposed delirium, treating even minor medical problems, involving family support, arranging practical help at home, arrange help for carers, drug treatment, and arranging institutionalized care in case of failure of home care are the basic principles of care. Drug treatment is used only when the possible side effects are outweighed by the benefits. In severe behavioral changes such as agitation and emotional instability, occasional use of sedatives is warranted (Promazine, Thioridazine). Antipsychotic drugs may be prescribed in delusions and hallucinations. If depressive features are profound, anti-depressant therapy may be started. Cholinesterase inhibitors acting centrally are of use to approximately half the patients suffering from dementia due to Alzheimer’s disease. They appear to delay the progression of cognitive impairment and in some cases may even improve symptoms for a time.


Psychosis is a critical disturbance of reality characterized by the presence of hallucinations and delusions. Hallucinations are realistic manifestations of things that are actually non-existent. Hallucinations can be divided according to the sensory system that perceive. They are visual, auditory, tactile, olfactory and gustatory. Delusions are firmly held beliefs that people hold on to despite overwhelming evidence to the contrary.

There are many psychotic disorders. Schizophrenia is the first and foremost among them. Psychotic episode may accompany mood disorders, thought disorders, and other psychiatric conditions. Anti-psychotic medications are the principal mode of treatment.

What is the difference between Dementia and Psychosis?

• Dementia is a loss of higher brain functions while psychosis is a loss of reality with all cognitive faculties intact.

• Dementia is common in the elderly while psychosis is not so.

• Dementia is untreatable while psychosis is treatable.