Why do some people have psychotic experiences?

Starting college, leaving school, moving out of the family home, bereavement, parental divorce are all major life events. Similarly, a relationship breaking up, family problems, debts, school or college exams are all stressors which can have an adverse impact on mood, health and functioning.

Many individuals will experience stressful events during the course of their lives and may experience changes in their mood and ill health following such events. Stressful events such as these can, in individuals who are susceptible to psychosis, trigger psychotic symptoms off in the first place or lead to further episodes of psychosis.

For some individuals, psychosis canh be triggered by the use of substances such as alcohol and drugs such as cannabis, LSD, cocaine, inhalants, toxic substances, anaesthetics. Psychotic symptoms usually occur during or shortly after (within four weeks) of the use or withdrawal of the substance.

Prescribed medication (and some over the counter herbal remedies) can, for some individuals who are prone to psychosis, trigger episodes of psychosis. Clearly when this becomes apparent, the individual will need to make sure that their GP is aware of their potential vulnerability to psychosis with some medicines, to avoid prescribing medication that might potentially trigger off further psychotic symptoms.

There is emerging research evidence to suggest that adverse early development expereinces, including a trauma or physical, emotional, sexual abuse, may predispose some individuals to develop psychotic symptoms later in life. However, it is important to note that many individuals who develop a psychosis have not expereinced trauma or abuse in childhood. Equally, many individuals who have had adverse expereinces when growing up do not go on to develop psychotic symptoms in later life.

Psychosis can run in some families. There is evidence to suggest that genes can play a role in influencing an individual's susceptibility to having psychosis. However genes are only part of the story and other factors such as childhood experiences and stress are likely to play an important role in the development of psychosis. If a blood relativein the immediate family, such as a parent, brother or sister has a psychosis, the risk of other family members developing psychosis increases from 1% to 10%. It is important to remember that where there is a family history there is a 90% chance that immediate relatives will NOT develop a psychosis. Equally, it should be noted that the majority of people who develop a psychosis have no history of psychosis in their immediate family.

Some physical health problems such a thyroid problems or left temporal lobe epilepsy can produce psychotic symptoms. It is therefore important for an individual to have a thorough examination to rule out any possible medical causes for psychotic symptoms that they may be experiencing. This may involve routine medical tests, such as blood and urine tests, and further investigation involving EED or a CAT scan (as well as a detailed interview with a mental health specialist).

Some of the factors described above may be more (or less) important for one individual than another. However, it is also important to note that many of these factors are also things which people have experience of without ever going on to develop psychosis. We still do not know fully why some people develop a psychosis and others do not. In first episode psychosis, the cause is often particularly unclear.

The cause and outcome of psychosis can vary considerably from person to person. The earlier a psychosis is recognised, assessed and treated, the better the outlook. It is also helpful if an individual who has expereinced psychotic symptoms can understand that they then have a vulnerability to psychosis and may need to address potential triggers which may be within their control such as illicit substance use, taking on too many demands and unhelpful lifestyles which may contribute to vulnerability. It is also important to learn coping skills for managing unexpected triggers such as stressful life events, in ways which can help the individual to preserve wellbeing and avoid further episodes of psychosis.