Difference between Dementia and Psychosis

Key Difference: Dementia is a broad category of brain diseases that cause long term loss of the ability to think and reason clearly. It can be said that psychosis is in fact a symptom of an illness. Dementia can cause psychosis.

The human mind is a fragile thing; while it is capable of great things, there are also various factors that may have an impact on its functioning. When a brain is not functioning as it used to, or there is an abnormality in the way the brain functions, it is called Psychosis.

It can be said that psychosis is in fact a symptom of a variety of illnesses, including dementia. Psychosis essentially refers to when the patient has "loss of contact with reality". People who are diagnosed with psychosis may experience personality changes, thought disorder, problems with social interaction, problems carrying out daily life activities. Some people with advanced psychosis may even experience hallucinations, delusions, sometimes violence, and impaired insight or understanding.

Psychosis can be caused by a variety of conditions, including but not limited to schizophrenia disorders, delusional disorders, bipolar disorder, personality disorders, brain tumor or cyst, neurological illnesses, HIV and other infections, epilepsy, stroke, genetics, dementia, etc.

Dementia is a broad category of brain diseases. It can cause long term loss of the ability to think and reason clearly. This loss of ability may be so severe that it may affect a person's daily functioning. Psychosis is another of dementia’s symptoms. There are many different types of dementia, including Alzheimer's disease, Lewy body dementia, vascular dementia, frontotemporal dementia, progressive supranuclear palsy, corticobasal degeneration, normal pressure hydrocephalus and Creutzfeldt–Jakob disease.

Dementia

Dementia builds up slowly and over time. By the time a person starts showing signs of the disease their brain was already being affected for a long time. Dementia most commonly effects memory, visual-spatial, language, attention, and executive function (problem solving). People who have been diagnosed with dementia might also experience impulsivity, depression, anxiety, agitation, balance problems, tremor, speech and language difficulty, trouble eating or swallowing, delusions, hallucinations, wandering or restlessness, etc.

Comparison between Dementia and Psychosis:

	Dementia	Psychosis
Description	Dementia is a broad category of brain diseases that cause long term loss of the ability to think and reason clearly that is severe enough to affect a person's daily functioning.	Psychosis refers to an abnormal condition of the mind, and is a generic psychiatric term for a mental state often described as involving a "loss of contact with reality".
	Group of illnesses	Symptom
Causes	Old age, genetics, traumatic brain injury, strokes, infections, interrupted supply of oxygen to the brain, epileptic seizures, acute hydrocephalus, excessive alcohol use, hypothyroidism, etc.	Schizophrenia disorders, delusional disorders, bipolar disorder, personality disorders, brain tumor or cyst, neurological illnesses, HIV and other infections, epilepsy, stroke, genetics, dementia, etc.
Signs and symptoms	Psychosis Loss of the daily ability Loss of the ability to think Loss of the ability to reason clearly Disinhibition and impulsivity Depression and/or anxiety Agitation Balance problems Tremor Speech and language difficulty Trouble eating or swallowing Delusions (often believing people are stealing from them) or hallucinations Memory distortions (believing that a memory has already happened when it has not, thinking an old memory is a new one, combining two memories, or confusing the people in a memory) Wandering or restlessness	Loss of contact with reality Hallucinations Delusions Catatonia Thought disorder Impairments in social cognition Personality changes Thought disorder Unusual or bizarre behavior Difficulty with social interaction Impairment in carrying out daily life activities Violence Grandiosity Pronoia/paranoia.
Types	Alzheimer's disease Lewy body dementia Vascular dementia Frontotemporal dementia Progressive supranuclear palsy Corticobasal degeneration Normal pressure hydrocephalus Creutzfeldt–Jakob disease	Menstrual psychosis, including circa-mensual (approximately monthly) periodicity, in rhythm with the menstrual cycle. Postpartum psychosis, occurring recently after childbirth Monothematic delusions Myxedematous psychosis Occupational psychosis Stimulant psychosis Tardive psychosis Shared psychosis Cycloid psychosis