10.5b Psychosis

i) A generic term for a group of symptoms

Psychosis is a generic term for particular group of symptoms that can include hallucinations, delusions and disorder of thought processes.


People who have a psychosis may have hallucinations. That is where they see or experience things that are not happening in reality. Auditory hallucinations such as hearing voices are the commonest types of hallucinations that people get.


Delusions are when people have an abnormal idea. They believe this idea and despite giving them evidence to show that their idea is not true or valid they still hold the idea. For example, a person might believe that they are being poisoned. Any type of food that is given to them they are not going to eat because they think that food is poisoned. No amount of reassurance is going to stop them thinking that they are being poisoned. That i s what we call a delusional idea.

Thought disorder

People who have a psychosis can have problems organising their thoughts which means that when they speak it does not make a lot of sense. Psychiatrists call this thought disorder. Thought disorder is rare in a psychosis that happens after a brain injury. However people who have a brain injury can have problems just organising their own thoughts without having a psychosis so it is always really important that if you think a person is having some of these symptoms to talk to a health professional about it.

    Image Courtesy of Peggy Cyphers, New York


ii) Psychotic illnesses

Some of the typical terms that you might hear when a person has a psychosis are:

  • schizophrenia
  • bipolar disorder.

The common feature between both of these illnesses is that a person can have psychotic symptoms.

When people have a brain injury their psychotic illness is very different to schizophrenia and bipolar disorder in a person who does not have traumatic brain injury. We know that over the longer term they do not have the same kind or number of episodes of illness as someone without a brain injury who has schizophrenia or bipolar disorder might have.

A lot of the people with a brain injury who also have a psychosis become very upset when someone suggests that they have schizophrenia because they themselves know that their illness is different but there are some characteristics that can be similar.

It can be sometimes very hard to distinguish between schizophrenia and a person who has a psychosis because they have had a serious brain injury.

Psychosis in the community generally is pretty rare, only about 1% to 2% of the population will ever have a psychotic illness.  (This is schizophrenia and bipolar disorder added together). But if you have a brain injury, your risk goes up by about 2 to 3 times, so about 3% of people who have a brain injury might develop a psychosis at some stage after the illness.

The closer the psychosis occurs to the time the person has had the brain injury the more likely doctors are to say that the psychosis happened because of the brain injury.

You may have a family member who got knocked on the head when they were about 11 or 12 and then when they were in their mid-20s they developed a psychosis. It is unlikely that the brain injury in this situation has caused the psychotic illness.

Psychosis is always caused by a chemical imbalance and so medication is always going to be part of the management of this illness.


iii) Difficulties in diagnosis

Psychotic illnesses can be hard to diagnose.

Mental health professionals need as much information as they can get to help them make a diagnosis.

One problem with diagnosing psychosis is that the symptoms are ones that most people know mean that you are mentally ill. For example, most people in the community knows that hearing voices means that you are mentally ill. So people are going to be very embarrassed about talking about hearing voices. If they have ideas that are delusions then they are going to stop telling people about the delusions because they are tired of hearing someone say – “Oh well that is not true, that is rubbish. Do not talk about that.” So they do not.

Th is proves to be a real challenge for the mental health professional because if they do not hear about the symptoms it is difficult to make the diagnosis.

Another problem with diagnosing psychosis is that a person can often control the symptoms or not talk about them when they are seeing the mental health professional. So if a member of your family has the type of symptoms described earlier, hallucinations, delusions, then it is important to go along and tell the mental health professional what you know about what they are doing. It might be the only clue that there is something more serious going on.

It is possible for a psychiatrist to talk to someone and think , oh I cannot find anything wrong with that person. What am I going to do? And then the family member or carer will come in and say you know they are doing this in the middle of the night, they are locking all the doors, they are talking about people breaking in and then the psychiatrist can ask more questions of the traumatically brain injured person and find out the kind of symptoms that are important for making the diagnosis.



iv) Psychosis and brain injury

A psychosis can start any time after the brain injury but the usual rule is that the closer to the time of the brain injury the more likely it is to be caused by the brain injury.

Damage to the temporal areas of the brain is an important reason why people can get psychotic illnesses.

Psychosis and marijuana

Marijuana or cannabis can have a role in starting off a psychosis.

It is common to see young adult males ( because men seem to smoke more marijuana than women), who used to be able to smoke marijuana before their brain injury without any problems.  After their brain injury they tend to go back to smoking the marijuana because they are bored, it gives them something to do, it stops them from feeling restless and agitated. But now they develop a psychosis.

We do not know why this happens but we do know that it is a common problem.  If the person stops smoking the marijuana the psychosis does not go away. So it develops a life of its own and then you need to have treatment for the psychosis. If people smoke marijuana while being treated for the psychosis then the medication does not work as well.

Psychosis after a brain injury is not like schizophrenia

Most people with schizophrenia develop the illness when they are young adults between the ages of 16 and 25.  When people (with no history of schizophrenia) develop psychosis after brain injury this is a different kind of illness course to schizophrenia. So someone who is 40 can develop a psychotic illness after a brain injury. We do not really know what the risk factors are for developing a psychotic illness, apart from the fact that if you have temporal lobe epilepsy, you have had damage to your temporal regions of the brain and a family history of psychotic disorders you have a slightly higher risk of getting a psychosis. Sometimes the only sign of a person having a psychosis is that they are aggressive, very irritable and irrational in the conversations you have with them.


v) Psychosis is always a biochemical problem

Psychosis is always a biochemical problem and we always need to use medication to treat it. There are two main types of antipsychotics, both work well, but differ in terms of side effects.  The drugs are divided by how long they have been available.

There are huge differences between them in that the more modern antipsychotics have much fewer side effects, they do not seem to cause problems with how the person thinks in terms of their memory function, and they do not get as many side effects that affect their neurological system. Some of the old fashioned antipsychotics slow down how people move or they find that they cannot go out into the sun. The more modern antipsychotics do not cause these problems. Examples of the old fashioned antipsychotics are:

  • Largactil (chlorpromazine)
  • Serenace (haloperidol)
  • Stelazine (trifluoperazine)

Examples of the newer antipsychotics are:

  • Zyprexa (Olanzapine)
  • Seroquel (Quetiapine)
  • Solian (amisulpride)
  • Risperdal (Risperidone)
  • Abilify (Aripiprazole)

Sometimes antipsychotics are used for problems apart from psychosis. They can be used for anger control. So if you have got a member of your family who is on some of the drugs that are listed there and think, Oh they must be psychotic, this may not be the case. The doctor might have started them because they are having problems controlling their anger and the antipsychotic can at times help . Modern antipsychotics can be very expensive to use and so the doctor may not be able to use it if the person does not have a psychosis.

Antipsychotics do not mix well with illegal drugs, particularly marijuana. If the person smokes marijuana and is taking an antipsychotic the antipsychotic does not work well.

People who develop a psychosis after a brain injury often need to have long term treatment. This is something that you are going to need to discuss with the doctor. We also use social treatments for psychosis such as talking therapies, sometimes people need help in how to mix with people in the community again.  However we need to treat the psychosis with medication first, get the symptoms under control before the talking therapies can occur.


Answer these questions:
1. What is a psychosis?
2. What are two psychotic illnesses?
3. What are two difficulties in diagnosis of psychotic illness?
4. Can using marijuana have a role in starting a psychosis?
5. What is always part of the treatment of psychosis?

Check your answers here
1. What is a psychosis?
A specific illness
A group of symptoms
2. What are two psychotic illnesses?
Anxiety disorder
Bipolar illness

3. What are two difficulties in diagnosis of psychotic illness?
Embarrassment about being mentally ill
Patient not talking about the symptoms
Family members talking about the patient's symptoms
Lack of agreed symptoms of a psychotic illness

4. Can using marijuana have a role in starting a psychosis?

5. What is always part of the treatment of psychosis?
Changing the patient's environment
Cognitive therapy
Social support for the patient