Who Is At Risk?Schizophrenia affects people from all walks of life. It occurs across the world in all countries and types of society, affecting all races and social backgrounds and on average about one in 100 (1%) of the general population will experience at least one episode of schizophrenia at some time in their life.
At times some scientists have suggested that there may be certain types of personality who may be prone to suffering with the condition but current think is that this is not the case.Age of Onset
Schizophrenia is predominantly a young condition. In fact about 70% of cases start in people aged between 16 and 25. It strikes most commonly in late teens and early twenties which is often a time when the person is going through considerable emotional and psychological changes as a normal part of their development. Because of this the early signs and symptoms are often not spotted by friends and family who may attribute disturbing changes in behaviour to normal adolescent development. However schizophrenia can also occur in older people in which case the chances of a good recovery are better.
Regional and racial variations in schizophrenia
There are some regional variations for instance some Scandinavian countries and parts of Ireland have a higher incidence. Similarly there are differences between some racial groups. For instance in the US studies have found a lower incidence of schizophrenia amongst the Hispanic and Amish communities than in the general population.1
Differences between men and women
The first episode tends to happen at a younger age in men than in women and women tend to do better under treatment than men, requiring lower doses of medication and experiencing fewer relapses.2Genetic predisposition
Schizophrenia tends to run in families so if you have a relation who has experienced the condition then you will be at higher risk. This risk increases to about 10% if you have a brother or sister with the condition and about 50% if that sibling is an identical twin. If one of your parents suffers from it then your chances are around 13% rising to about 45% if both of them suffer.3
Time of year differences
One of the most interesting features of this illness is that it seems to show a preference for certain seasons of the year. People born between January and April have a 5 to 10% increased risk of developing schizophrenia than people born at other times of the year. Episodes tend to be seasonal as well with more in-patient admissions during the summer than the winter.4Schizophrenia: an urban condition
People who have been born or raised in an urban environment have approximately twice the risk of later developing schizophrenia than people who have been born or raised in a rural setting. Why this should be so is not yet fully understood.5
Complications at birth
Complications during pregnancy and around the time of birth appear to double the risk of developing schizophrenia later in life.6 It is thought that this may be due to oxygen deprivation during birth although some have postulated that viral infections may be to blame.
Use of street drugs and schizophrenia
It has long been known that some drugs can induce symptoms of psychosis. For instance amphetamines (speed) and cocaine are well known to cause paranoia and LSD causes hallucinations. But so far only one drug, cannabis, has been said to cause permanent psychosis. The link between cannabis and schizophrenia has for some years been very contentious but there is now a strong body of research evidence emerging that shows that if you use cannabis you are considerably more likely to go on to develop schizophrenia.Studies have shown that if you use cannabis you are more likely to develop schizophrenia than if you don’t with various studies finding the increased risk up to six times higher. Furthermore use of cannabis or other street drugs following the first episode of schizophrenia will leave you more liable to a relapse and involve you in more admissions to hospital.7 Migrants
Recent studies have shown that first and second generation immigrants have a much higher risk of developing schizophrenia and that this risk is greater if the migrants originate from countries where the population is black in ethnic origin.8 Why this should be so is not yet fully understood and there are a number of theories including susceptibility to certain virus infections and lack of sunlight. This may at least in part explain the very much higher incidence of schizophrenia amongst young Afro Carribean men in the UK.
1. Fuller Torrey E, 2001, Surviving Schizophrenia, Quill, p13.
2. Fuller Torrey E, 2001, Surviving Schizophrenia, Quill, p128.
3. Burton N, 2012, Living with Schizophrenia, Acheron Press, p14.
4. Burton N, 2012, Living with Schizophrenia, Acheron Press, p18.
5. Fuller Torrey E, 2001, Surviving Schizophrenia, Quill, p12.
6. Warner R, 2000, The Environment of Schizophrenia, Brunner Routledge, p17.
7. Burton N, 2012, Living with Schizophrenia, Acheron Press, p18
8. Reveley A, 2006, Your Guide to Schizophrenia, Hodder Arnold P53.