Schizophrenia Blog

6 Environmental Risk Factors for Schizophrenia

Nov 3, 2013, 7:34 pm

Planning the steps you can take to recover from schizophrenia is very important, but what if you could take preventative action? This is possible also and very important for parents of children with risk factors. The chances of a person developing schizophrenia are much higher if a close relative has it, so understanding the environmental factors that lead to schizophrenia, can allow parents of at "risk children" to increase the odds for their children.  

To understand how it may be possible to prevent schizophrenia, it is first necessary to look at its causes.  For some time it has been accepted understanding that two factors (a) Genetics and (b) Environment play a role in the development of schizophrenia.  Current thinking is that a genetic predisposition is compounded by environmental factors. These environmental factors have a substantial influence and without these schizophrenia will not develop, despite the predisposition.

As we have no ability yet, to change our genetics, we have to look to the parts of our environment that we can influence.  Environmental factors can be broken into two groups: prenatal and postnatal. This article is about the postnatal environmental factors that can influence the chances of developing schizophrenia. Many of these you may not be able to influence and some are interrelated, but it is nevertheless prudent to be aware.  

1. Living in a City

Moving to the countryside might not be an option but rates of schizophrenia are higher in urban areas and this has been known since a famous (at least among those who study schizophrenia) study by Fassis, RE and Dunham,HW in 1939.   That study was conducted in Chicago. There have been many studies since that show, not just the urban rural contrast, but also within-city neighborhood contrasts in the rates of the disorder.  In 2004 psychiatrists Spauwen J et al., looked at 10 different studies in their work “Does urbancity shift the population expression of psychosis?” They found that studies indicated that the rates of schizophrenia in urban areas are about twice the rate in rural areas. They also found that  age, sex, ethnicity, drug use, social class, family history, season of birth and other factors could not explain the apparent association between schizophrenia and city.

The  exposure to the city during development in childhood and adolescence appeared to be more important than exposure in adulthood or around the time of onset of schizophrenia.

There is a lot more that I want to say about this risk factor, but I will make that the subject of a separate blog. I have mentioned this factor first in this list because it explains around 30% of all schizophrenia incidences (if you accept causation), making it possibly the most important of all environmental risk factors.   

2. Early Childhood Trauma

When researchers began to look at the life experiences of individual patients,’ childhood trauma and the development of psychosis appeared to be linked.  In 2012 researchers at Liverpool and Maastricht University in the Netherlands completed a study that brought together and analyzed more than 30 years of studies with respect to the link between childhood trauma and the development of psychosis. Data was extracted for more than 27000 research papers and the results led to the conclusion that children who had experienced any kind if trauma before the age of 16 are 3 times more likely to develop some form of psychosis in adulthood compared to a random selection of individuals. The study found correlation between the extent of the trauma and the likelihood of psychosis with severe trauma potentially increasing the risk factor to 50 times. Various trauma such as sexual, physical and emotional abuse, death of a parent, school bullying and neglect were all implicated.

This is a big topic as studies have linked different types of trauma to different types of psychotic disorders. If this factor is of interest to you please leave a comment and I can provide further details. 

3. Vitamin D

Studies have consistently linked lack of Vitamin D with the development of schizophrenia. The vitamin appears to reduce the incidence of schizophrenia in people whose mothers took the vitamin prenatally, but the benefits of the vitamin do not stop here. Other studies have shown that taking Vitamin D can prevent the onset of schizophrenia.

Ensuring that you receive sufficient levels of Vitamin D is of course one of the easiest factors to control and its importance has been re-emphasized in a 2012 study.  An in-patient facility in the UK tested 140 people at the facility upon their arrival with a first episode of psychosis. While the study showed that the patients had significantly lower levels of vitamin D than controls of the same age, they were also 3 times more likely to have a full blown vitamin D deficiency.

Studies have been conducted before of in-patients, but this is the first time that any study of patients with a first episode has been conducted to determine vitamin D levels. It is significant because while it may have been expected that patients on wards (being indoors) could suffer from a deficiency,  the knowledge that such deficiency exists even in those that have not been hospitalized or suffered from psychosis tends to suggest a greater link.

4. Latitude and closeness to the equator

There is a large variation in the prevalence of schizophrenia at different geographical locations. The closer a person lives to the equator the lower the incidence of schizophrenia.  Researchers noted that this may to some degree be because of the role of Vitamin D which comes from the sun.

Despite the fact that there are more developing communities in areas close to the equator, and therefore, poor prenatal healthcare and nutrition (which would typically increase the risk for schizophrenia) the overall incidence of schizophrenia is still lowest at sites near the equator. This suggests that the protective environmental factor of better healthcare in industrialized countries  is overwhelmed by the negative effects of living further from the equator.  

5. Substance Abuse

It seems obvious to me but I will mention it anyway, that substance abuse (and in particular marijuana) have an impact on the development of schizophrenia.  The studies are so numerous and easy to find that they do not bear mentioning. I should say though that use of marijuana under the age of 21, when the brain is developing, leads to an even higher risk and heavy use has been associated with an increase in developing schizophrenia of  500 to 600 times. 

6. Nutritional

As a nutritional company producing a supplement for schizophrenia we would be remiss if we did not point out that your choice in taking supplements is another environmental factor.  There are studies that indicate that some of ingredients in SBX not only reduce symptoms or make antipsychotics more effective but may also reduce the chances of developing schizophrenia. In particular antioxidants appear to have a protective effect on the brain.  Researchers have also noted that there is lower incidence of schizophrenia in communities that have diets high in fish and there appears to be a link, for example, between gluten and schizophrenia.  So as you are trying to make health changes to your life don’t neglect these. There is information about them all over our site.


Leave a Comment

E-mail Id:



Buy Supplements

SBX Vitamins Supplement multivitamin

SBX Supplements for Schizophrenia

SBX is a supplement for those suffering from schizophrenia. The formulation contains the different vitamins and natural ingredients that studies suggest may reduce the symptoms of schizophrenia and help with recovery from schizophrenia.

$29 per bottle (Total of 60 capsules) 

Add to Cart

Blog Useful Links

Mental Health Blog Directory
Online Marketing
Add blog to our directory.

This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease. The information
contained herein is for information purposes only and is not intended as a substitute for advice from a physician or other healthcare professional or any information
contained in the product labeling.