January 05, 2007

A Positive Relationship With Both Parents During Childhood May Protect Against Schizophrenia in Adulthood

In a study published in 2002 it was reported that among those individuals who were considered at high-risk for schizophrenia, those with poor relationships with their parents were more likely to develop schizophrenia than those who had reported a good one. The authors of this article suggest that positive parental relations may help to protect the individual from developing schizophrenia. In this study 23% of high-risk subjects with poor relationships with both parents developed schizophrenia versus only 7% of high-risk subjects with good parental relationships.

Before we go into greater depth on this study we want to note that recently, we reported on the theory that child abuse is a "cause" of schizophrenia. The mainstream scientific establishment indicates there is no strong support for this hypothesis. However, just as with many other forms of stress (complications during pregnancy and birth, drug use, head injuries, etc) that appear to be important in the risk for schizophrenia (especially those who have a family history of the disease), scientists suggest that child abuse may likely also turn out to be a risk factor for some individuals. Here, we must be clear by what it means to be a "risk factor": A risk factor does not mean something that "causes" the illness necessarily, but instead means something that is associated with an increased risk and may simply be correlated with the illness.

A simple hypothetical real world example describing how the use of "cause" can be misapplied follows:

Hypothetical finding: "Frequent visits to McDonalds restaurants cause an increase in heart disease". This is an erroneous use of "cause" for a couple of reasons. First, "Frequent visits to McDonalds" is not what drives the association between the hypothetical increase in heart disease. Frequent visits to McDonalds are not causing the increase in heart disease; they are just correlated (associated). In fact, we all know it is not the physical act of "visiting McDonalds", but what people are eating during those frequent visits, and how their particular genotype responds to fatty food substances that is the true association and may possibly have a causative influence on heart disease risk.

Take home message: Risk factor means there is an association or correlation but, not necessarily a causative association. It is also very easy to misapply causation for correlation and even to conclude a meaningful association when it’s really just a meaningless one. Its always important to keep this in mind.

The beauty of risk factors is that they may lead to clues to the true cause of the illness (e.g., Hypoxic (reduced oxygen) injury during pregnancy and birth are associated with schizophrenia. Hypoxia affects selected regions of the brain during neurodevelopment. Those regions may then be earmarked for further study in schizophrenia neuropathology and neurodevelopment which then may lead to identification of the actual cause of the illness by narrowing down the malfunctioning neurology). Furthermore, risk factors provide hope that we can identify “preventive factors” (i.e., eliminate the risk then you are essentially creating a preventive measure). It is this second advantage of risk factors that the following summary discusses. Specifically, the study that is reviewed examines the question of the parent-child relationship prior to the onset of schizophrenia and whether it may have any influence on risk/prevention.

A Review of "Perception of parent-child relationships in high-risk families and adult schizophrenia outcome of offspring." Journal of Psychiatric Research, 36 (2002) 41-47.

Journal Study Summary By: Anne Whitney, Masters in Psychology


Does the parent-child relationship influence the outcome of people who are at-risk for developing schizophrenia? Schiffman et. al (2002) hypothesized that among high-risk individuals (or people whose mothers were diagnosed with schizophrenia), individuals who had experienced negative relationships with their parents would be more likely to develop schizophrenia as an adult.


This study was based on the information gained from a 38-year long study by Mednick and Schulsinger (1962). These Danish researchers followed 207 high-risk subjects (children of mothers with schizophrenia) and 104 low-risk subjects (children of parents with no psychiatric illness) from adolescence into adulthood. In the beginning of the study, each child was given a variety of psychiatric tests as well as interviewed by an experienced social worker in order to determine how that child perceived his/her relationship with his/her parents. Many years later, the same subjects were given more psychiatric tests and were screened for psychiatric hospitalizations.

What they found:

Results from this study indicated that high-risk subjects had significantly worse relationships with their parents than low-risk subjects. Among those individuals who were considered high-risk, those with poor relationships were more likely to develop schizophrenia than those who had reported a good relationship with their parents. The authors of this article suggest that positive parental relations may help to protect the individual from developing schizophrenia.

Possible weaknesses of the study:

Critics of this theory suggest that genetic risk alone probably causes behaviors that negatively affect the parent-child relationship. Though the authors attempted to find out to what degree genetic makeup may have caused relationship problems, they concluded that the level of genetic risk does not necessarily impact the relationship, but did not rule out the possibility that the genetic factors caused behaviors that impacted the parent-child relationship and later accounted for the onset of the disorder. That being said the authors also noted that in 1991, Tienari et al. found that high-risk individuals who were adopted into a healthy family were less likely to develop mental disorders than high-risk individuals who were adopted into disturbed families.

Another possible weakness of the study involves study design wherein there is no mention whether the examiners who conducted the parental-child relationship interviews and completed the scales were blinded to the high risk or low risk grouping of their subjects. Of course, even with blinding, the nature of the symptomatology of schizophrenia may have made it very difficult to prevent examiners from knowing which were high risk and which were low risk families. Additionally, the era in which the interviews were conducted (1962) may have slanted the evaluations towards “expected” greater parental pathology in the high risk families. In other words, the examiners might have subconsciously applied a more critical or “pathology-seeking” attitude towards the high risk families since the evaluations were done in an era where the “schizophrenogenic” mother was all the rage.

Lastly, while not a weakness, more of an area that might have been informative for the question of whether genetic loading of schizophrenia was driving part of the association, a more thorough comparison of parent-child relationship as it relates to severity of illness (e.g., age of onset, course, medication responsiveness) in either the offspring or in the parents would have been helpful, and whether one or both parents (or otherwise multiple persons in the family) had the illness. Possibly, the families who show a history of poor parent-child relationships are related to a more severe form of schizophrenia.

Final take home message: Though one cannot conclude that poor parental relationships cause the onset of schizophrenia, this study demonstrated an association between negative parent-child relationships and the development of schizophrenia. More importantly, like the Tienari et al. study (1991), the findings suggest positive parent-child relationships may help to protect the individual against schizophrenia, and probably many other health issues.

Hopefully, additional studies designed to avoid the potential examiner bias (interviewers knowledge of family history), and to understand more fully the possibly “interactive” effect of a negative (or positive) relationship with ones parents and the genetic risk for schizophrenia where 23% of high-risk subjects with poor relationships with both parents developed schizophrenia versus only 7% of high-risk subjects with good parental relationships in this study will occur.

Source Study: Perception of parent-child relationships in high-risk families and adult schizophrenia outcome of offspring
Schiffman, J., LaBrie, J., Carter, J., Cannon, T. Schulsinger, F., Parnas, J., Mednick, S.
Journal of Psychiatric Research. 2002 (36):41-47.

Related Reading:

Lower level of Family Stress May Reduce Risk of Schizophrenia in Children

Is It Psychological Or Biological?

Broken Homes Linked to Increased Risk of Psychosis, Schizophrenia

Child Abuse and Mental Illness - Nature and Nurture

Early Family Experience Can Eliminate the Effects of Genes, Minimize Risk of Mental Illness

Childcare, Genetics, Epigenetics and Schizophrenia


I note the use of the phrase
'how that child **perceived** his/her relationship with his/her parents.

Perceptions can be distorted as a result of being mentally ill.

It would have been interesting to see how a non mentally ill control group rated the relationships and what the incidences of sz based on their **perceptions** were.

Also how non mentally ill members of family perceived the relationship.

Posted by: Tim at January 5, 2007 08:20 PM

I have Paranoia Schizophrenia
and this article is about 95% correct about me. Although I had good parents in my life my childhood in school was bad. That is the only slight difference

Posted by: Timothy S Knupp at January 6, 2007 12:00 PM

Although I had good parents in my life my childhood in school was bad. That is the only slight difference

That is actually a big difference, because supposedly, 1- the good relationship with parents is supposed to be able to protectively offset the other usual life and school hassles, and 2- Problems at school (including with teachers and classmates) can be due to the fact the child already has problems affecting the brain (prodrome).

Posted by: Naomi at January 7, 2007 10:44 AM

I was bullied a lot especially during age of 13-18. It was because i was 'different'- shy/ physically awkward/socially gauche. Childhood problems of a mental health nature weren't so readily acknowledged in the 60'and 70's.
I have no doubt that if i had been a child of the 90's/2000's i would have been picked up by child mental health services.
Although 'bright' i also had areas of cognitive deficit which would have been picked up on nowdays.

My relationship with my parents as a child is best described as 'dysfunctional'.

Posted by: Tim at January 7, 2007 02:21 PM

I think the people who abuse children are mentally ill, but they usually get away scott free and their prey suffer in proxy for the offenders "disease," of vanity.

Posted by: Dorothy at January 22, 2007 08:10 AM

Perception of the past in patient with schizophrenia has been shown in studies with their siblings to not be a scientifically valid indicator. Their remembrances were found to be abnormally negative.

Posted by: Dr.Vic at February 7, 2007 03:45 PM

If anyone could email me because I'm doing a projects for biologly on Schizophrenia that would be nice thank you in advance for all those who chose to help

Posted by: Ashley at March 2, 2007 09:03 AM

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