Psychosis

Psychosis is a mental health condition. People who have psychosis are called psychotic.  They have trouble telling the difference between what is real and what is not. They may have hallucinations, delusions, personality changes, and/or paranoia. Psychosis is a kind of altered state of consciousness.

Psychosis may be caused by medical or psychiatric factors. Poisons, drugs, diseases of the nervous system, tumors, and other illnesses can cause psychosis. So can schizophrenia, bipolar disorder, depression, and/or brain damage.

 Name 
The word "psychosis" has two parts. The first part comes from psyche, which means soul in Ancient Greek. The second part is the ending, -osis, which means illness or unnatural condition. So psychosis means unnatural condition of the soul.

 Symptoms 
People with psychosis may have hallucinations and/or delusions (fixed beliefs and ideas that are usually false). Sometimes their personality changes, and they cannot think straight. Some of these thoughts may be paranoid. However, not every psychotic person has all of these problems. 

Psychosis can make it difficult to live a normal life as part of society. People with psychosis often have trouble with making friends, as most people do not understand them.

Psychosis can affect people to different levels. Some people can continue with mostly normal lives, while other people will need a lot of medical help.

 Religion & supernatural experiences 
Many people on Earth have had supernatural or religious hallucinations that they believe are real (like sightings of the Virgin Mary). According to Johns and Van Os (2001), these cases may just be an extreme version of something that many people experience. 

However, religious delusions can also be a symptom of schizophrenia.

People with schizophrenia with psychotic symptoms have a problem with thinking about practical things because they are thinking very much more about abstract things.Pierre Maurage, Pierre Philippot, Delphine Grynberg, Dominique Leleux, Benoît Delatte, Camille Mangelinckx, Jan-Baptist Belge, Eric Constant Imbalance between abstract and concrete repetitive thinking modes in schizophrenia Compr Psychiatry. 2017 Oct:78:61-66. doi: 10.1016/j.comppsych.2017.06.013. Epub 2017 Jul 1.Ann Olson Psy.D.Schizophrenia and Modes of Thought Convergent and divergent thinking are examined in terms of schizophrenia. Psychology Today 

In movies and the media in general, violent and antisocial people are sometimes called "psychotic." This image of psychosis is wrong. The people shown are usually psychopaths or sociopaths, not people with psychosis. They usually do not have hallucinations or delusions.

Causes

 Substance-related causes 
Certain medications can cause psychosis. So can misusing certain drugs (like amphetamines, cocaine or alcohol). Drug withdrawal can sometimes cause psychosis, as in delirium tremens from alcohol withdrawal.

 Medical conditions 
Medical conditions that can cause psychosis include:

 Brain cancer
 Severe brain injury
 Thyroid problems
 Brain infections
 Certain types of epilepsy
 Hormone-related conditions
 Meningitis
 Lupus
 Lyme disease
 Multiple sclerosis
 Parkinson's disease
 Stroke
 Deficiencies of vitamin B1 or vitamin B12

 Psychiatric causes 
Mental disorders that can cause psychosis include schizophrenia, bipolar disorder, and severe depression. Severe psychological stress can also cause psychosis.

Severe lack of sleep can cause psychosis. This is not a problem for most people.  Most people only experience hallucinations shortly before going to sleep or shortly after waking up, which is considered normal.

Postpartum psychosis is a rare but severe mental health emergency related to postpartum depression.

 Unknown causes 
Sometimes, the reason for a person's psychosis is not clear. Some of these psychoses may be linked to genetic factors.  A person's risk for psychosis may be related to certain events during their mother's pregnancy or their early childhood.

The first episode of psychosis may be triggered by stress.

Treatment
Most psychoses can be treated, so that those suffering from them can lead a normal life. The treatment depends on the cause of the psychosis. In general, there are two different forms of treatment available:
There is a class of drugs called  antipsychotics. These usually work by changing the way the brain and nervous system react to neurotransmitters.
There is therapy for psychotic people. This works by teaching them to recognise when they have an episode of psychosis, and to react to it in certain ways.

References