While the initial risk factor in development for schizophrenia is now known to be biological and genetic - it is also known that just having the genes is not enough for the development of schizophrena - there must be environmental factors that contribute to and ultimately triggers schizophrenia.

One of the key factors seems to be the stress that a person experiences in their life - especially longer term, or ongoing stresses. One long term stressor that research has identified is the stress that can be created in a child due to different parenting styles. Just as some people's interpersonal styles can cause stress in a relationship - they can also cause stress in children. Research is increasingly showing that these social skills (for more info see our article on social intelligence) can have an important roll in the development of a child. When parents have anxiety (excessive worry) and depression - it can get passed on to children and result in ongoing stress for the child. Mothers who have anxiety, and who worry too much tend to over control their children, and over control tends to cause children ongoing stress. Research also suggests that children learn negative styles of thinking from parents who suffer from depression or anxiety. These negative styles of thinking result in much greater stress over long periods of time because people who have them tend to look at the negative (or dark) side of many more situations than a mentally health person does.

Following is an excerpt of a discussion with Dr. Robbin Murray of the UK, a leading researcher in the causes of schizophrenia.

Maternal care and Schizophrenia

SRF: Let's talk about maternal care. That's interesting historically because poor parenting was blamed for schizophrenia in the middle years of the 20th century. Then the realization of a genetic component seemed to throw that out for a while and lifted the guilt off the shoulders of parents. Now, though, work by Michael Meaney and other groups revisits the issue in a different form (see, for example, Meaney and Szyf, 2005).

RM: I don't think he works on schizophrenia.

SRF: No, he studies the regulation of the stress response. But how robustly you can withstand stress, social adversity, and anxiety is part of the risk predisposition to schizophrenia.

RM: Yes. We've always known that people with schizophrenia were more anxious or depressed, and we thought that came later because they're hearing voices, they think they're being persecuted, they've got no money, they've got no friends. But people with schizophrenia have more depression and anxiety at the beginning of their illness; indeed, the anxiety and the depression often come before the psychotic symptoms. We've done cohort studies following children from birth, and they, too, show that children who are going to go on to develop schizophrenia have more depression and anxiety than the general population. So another way of looking at it is that these individuals are vulnerable to anxiety and depression, and that the anxiety and depression may contribute to them developing psychosis. To this extent, social factors that impact on anxiety and depression might contribute.

SRF: Does that say anything new about parental care and risk for schizophrenia?

RM: This is a tricky area. Schizophrenia researchers are deeply ashamed of the era when parents were accused of having contributed to the cause. Remember the era of "refrigerator mothers" and "schizophrenogenic mothers"; the specious argument that the way parents communicated with their children drove them mad. I think particularly biological psychiatrists were so ashamed of that episode that we did not study family factors and at the possibility that they could contribute. We just avoided it.

But when you do begin to look, you find an effect. We've done a number of cohort studies where you take, say, 5,000 children, you examine them throughout childhood, and then you follow them up to see who develops schizophrenia. It's quite clear from that research that children with a poor relationship with their mother do have a higher risk.

That raises the question of whether the child is so odd to begin with that even the best mother in the world can't make a good relationship with him or her. And there's also the possibility that mum may be carrying some susceptibility genes, as well, and may therefore have some minor spectrum characteristics. But I think the evidence is beginning to suggest some effects in those who are genetically vulnerable, whereby the more socially hazardous your upbringing, the more at risk you are. Also, adoption studies have looked at adopted children of schizophrenic mums placed with families versus those placed in orphanages, and the ones placed in orphanages have a higher risk than those with a good adoptive family. This evidence, too, does seem to show that the social environment can compound the genetic predisposition.

The original source of this interview is the Schizophrenia Forum web site - you can find the entire interview here.

Additional Reading:
Lower level of Family Stress May Reduce Risk of Schizophrenia in Children

Emotional Intelligence - background information

Social Intelligence - background information