Saturday, October 22, 2005

Child abuse and schizophrenia?

The following is taken from, 14 March 2005:

Child abuse and schizophrenia?

Abuse as predictor for schizophrenia?

The following series of reviews concern articles written about the relationship between child trauma, mainly sexual or violent abuse, and subsequent psychiatric illness. Certainly, child abuse is a rampant problem and one that has lasting consequences upon its victims. However, it is unclear precisely what risks are conferred upon those with violent childhoods. I did a brief review of the literature for articles that were about the risk of psychotic illness and schizophrenia in people with a history of child abuse.

The best article was written by Spataro, et al. It is a cohort study in which they looked at children born in Victoria, Australia from 1959 to 1991. They compared over 3,000,000 children (both males and females) with the 1621 reported cases of child abuse on file. They compared the rates of diagnosis of various psychiatric illnesses between the groups.

Summary of findings:

1. The rate of psychiatric illness in the abuse group was 4x that of the control group (12% vs. 3%).

2. Rates of schizophrenia and schizophrenia spectrum disorders did not differ between the groups.

3. There was a significantly increased risk of developing a mood disorder, behavioral disorder, childhood psychiatric disorder, anxiety disorder and personality disorder in the group that had reported abuse.

4. There was no significant difference in risk for alcohol and drug abuse between the groups.

5. Men were statistically more likely to have a behavioral and/or childhood psychiatric disorder than women, but no difference was seen in other disorders between sexes.

There were many limitations in this study. The way that the cases were found required them to have sought treatment in the public mental health facilities in Victoria. While most significant illnesses will be picked up this way, if someone was able to afford to only have treatment in the private sector, they might be missed as a case. Perhaps more importantly, the rate of reporting of sexual and physical abuse is very low. This means that the control group likely has a portion of its group that actually suffered some childhood trauma. It is worth noting however, that if that were the case, it would likely make the differences between the groups less. This is because if the control group actually had a significant number of abused people in the group, that group would begin to mimic the abused group and the differences would be less obvious. With a four fold difference between the groups this limitation may not have been a significant problem. However, it does appear that was too great a problem, though the authors speculate that the reason that there was no discernible difference between the groups with respect to alcohol/drug disorders may have been for that reason.

Additionally, it is important to keep in mind that while no difference was noted for schizophrenia, the mean age of subjects was in the early 20’s. Schizophrenia is a disorder that generally strikes in the late teens and early 20’s but by no means is finished by then. As a result, it is possible that cases of schizophrenia had not developed by the time of the data analysis for this study.

In the Read et al. (3), study from New Zealand, they looked at a sample of 200 consecutive patients seen in their clinic. Looking back at their charts, they calculated how many people had evidence in their records of having previous sexual or physical abuse. They found that people with history of abuse as children, both physical and sexual, had an increased likelihood of having hallucinations. Interestingly, there was not an increased risk of delusions, but all forms of hallucinations including auditory, tactile (feelings things touching), visual and olfactory (smelling things that aren’t there.) Of concern was that command auditory hallucinations (hearing voices that tell the person to do something, potentially self-injurious or violent), were also increased in the abuse victims compared to those without a report of mistreatment. The only difference shows with respect to delusional thinking was an increase in satanic/devil beliefs by children with either sexual or physical abuse.

There were limits to this study. Namely, it was performed as a chart review and therefore the information was limited to what was documented by the clinician originally seeing the patient and without the intent at that time of using the data for research. Therefore, it is possible that some of the history was not taken as precisely as it might have been had it been done for research purposes. It is also difficult always to know for sure the validity of abuse claims taken retrospectively. While there is no reason to assume that those with schizophrenia are any more likely than anyone else to report abuse inaccurately (both to include reports of abuse that didn’t happen or to deny abuse that did happen) it is something that is a source of question. In this case, the researchers note that their sample had a lower rate of abuse than is typically seen in research leading them to wonder if some victims were missed. There was corroboration of the sexual abuse claims in 70% of the cases, but not all, and there is no way to know precisely who wasn’t reporting abuse that should have. This study also did not control for parental effect. Abuse, as well as schizophrenia, are both known to be heritable. It is possible that if a parent was both someone who suffered abuse as a child and had schizophrenia, that might increase the risk for both in their offspring. It should be noted though that even when that factor is considered, in other studies, the relationship between abuse and schizophrenia has held up.

Overall, this study concludes that victims are childhood sexual abuse are roughly 2x as likely to experience the significant and serious symptoms of schizophrenia. Much of the increase was due to hallucinatory symptoms but there was some increase (though not necessarily significant statistically) for increased rates of negative symptoms and some delusions like devil/satanic beliefs. These results are in line with the other Read paper (#4) that also showed increase rate of hallucinations in people with a history of sexual abuse. That paper also emphasized the point that people with a history of sexual abuse, who also have hallucinations, are not having “pseudohallucinations” that are related only to the abuse, but are having equally serious psychotic symptoms as others who have hallucinatory sensations.

1: Spataro J, Mullen PE, Burgess PM, Wells DL, Moss SA. Impact of child sexual abuse on mental health: prospective study in males and females.Br J Psychiatry. 2004 May;184:416-21. PMID: 15123505
2: Read J, Hammersley P. Child sexual abuse and schizophrenia.Br J Psychiatry. 2005 Jan;186:76; author reply 76. PMID: 15690589
3: Read J, Agar K, Argyle N, Aderhold V. Sexual and physical abuse during childhood and adulthood as predictors of hallucinations, delusions and thought disorder.Psychol Psychother. 2003 Mar;76(Pt 1):1-22. PMID: 12689431
4: Read J, Argyle N. Hallucinations, delusions, and thought disorder among adult psychiatric inpatients with a history of child abuse.Psychiatr Serv. 1999 Nov;50(11):1467-72. PMID: 10543857


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