Schizophrenia and autism

Thanks for linking to the Pediatrics free online entire article. Reading the abstract and the commentary on science websites one gets the impression that shizophrenia is rampant among parents of autistic children. A full reading of the entire article (thanks again)gives an entire different impression, especially to those who take any major autism announcement with a large grain of salt.

Thee rate of schizophrenia reported (7 mothers and 8 fathers) represent 1% of the entire sample of nearly 2500 parents of the autistic people. It has been known and accepted for decades that the prevelance of schizophrenia in the general population is 1%... Where's the linkage? It would be expected that 1% of any group would have a parent who was diagnosed with schizophrenia from everyone with red hair to everyone who is right-handed.

The control group, randomly selected, did have a lower prevelance of schizophrenia than did the autistic group, but the autistic group did not have a higher prevelance that the universally accepted rate of 1%.

In political preference polls this is known as an outlier where 7 polls have candidate A with an 8-12 point lead and one poll has Candidate B with an 10 point lead.

For example,this study was based on patient registries in Sweden, but in next door neighbor Finland, another study of (twins) found the prevelance of schizophrenia to be 2%, twice as high as the 1% general population prevelance.

http://archpsyc.ama-assn.org/cgi/content/abstract/55/1/67

The myth that schizophrenia is linked to autism has been dispelled by many of the most distinguished researchers in the field from Eric Schopler to Michael Rutter.

It is important for parents to simply not accept at face value any study that receives widespread media attention without raising reasonable critiques of the information being promulgated to the media.

Hi RAJ, and thank you for your comment.

One thing I wanted to note for our readers is that talking about rates of illness can get very tricky. For example, sometimes researchers will give a percentage that represents "lifetime prevalence" of a disorder -- that is, the chance of having it ever, during your whole life. Other times, they may estimate how many people in the population have the disorder right now, or have had it in the past year. They may also limit this by age group, gender, or some other characteristic.

For example, on the National Institute of Mental Health (NIMH) website, they write: "Schizophrenia is a chronic, severe, and disabling brain disorder that affects about 1.1 percent of the U.S. population age 18 and older in a given year." The lifetime prevalance may be something else again.

NIMH website: http://www.nimh.nih.gov/health/topics/schizophrenia/index.shtml

So far, in the IAN data, we have not seen high rates of schizophrenia (current or past) among parents of children with ASDs. Only .4% of fathers and .2% of mothers have reported a history of schizophrenia.

(It should be kept in mind that our data is self-report, not based on clinical records.)

On the other hand, parents, especially mothers, participating in IAN have reported extremely high rates of depression -- which is similar to another finding in the study you were referring to. Hopefully, responses to our upcoming Parental Depression History Questionnaire will help us to explore that entire issue in more depth.

For those who are interested, the abstract of the study on schizophrenia and depression in parents of children with ASD is here:

http://www.ncbi.nlm.nih.gov/pubmed/18450879?dopt=abstract

Thanks Connie for the NIH link on the prevelance of schizophrenia in the US (1.1). Actually my math was wrong regarding the article on mental illnness in parents of autistic people. The actual lifetime prevelance cited in the article was less than 1%, .667% (Fifteen parents out of over 2400 biological parents).

Ironically, if you use the NIH prevelance of 1.1 it could be reasonbly argued that the prevelance of schizophrenia in the parents of autistic people (.667) represents a biological resistance, rather than susceptability, for parenting an autistic child.

My understanding is that autism and schizophrenia are both linked to mitochondrial disease.

Schizophrenia and autism are both listed as atypical presentations of mitochondrial disease according to Table 3 in the publication below

The Spectrum of Mitochondrial Diseases

http://biochemgen.ucsd.edu/mmdc/ep-3-10.pdf

Just a thought to add: It is likely that autism has multiple causes, and that there are in fact multiple "autisms." The search for meaningful subtypes of autism based on concrete, observable biological differences drives much of current research.

So there may be a "mitochondrial" version of autism, but it would exist in addition to other kinds. In one article, where they reported on two cases of mitochondrial dysfunction and autism, the authors stated that, "Mitochondrial disorders are rarely reported in autistic children." They also noted, however, that mitochondrial disorders are so difficult to diagnose, it is possible there are cases where they are present but not identified. They conclude, "The mitochondrial disorders can be associated with autistic disorder as shown in the literature and should be included in the differential diagnosis of secondary autistic disorder." You can read the abstract here: http://www.ncbi.nlm.nih.gov/pubmed/17890412?dopt=abstract

Other subtypes that have been hypothesized include a high functioning type of autism associated with a family history of mood disorder (that is, depression or bipolar disorder) and a type of autism associated with immune issues, GI problems, and regression.

Getting to the point where subtypes are identified and understood in biological terms is important, because this permits development of focused treatments that may be different depending on subtype.

I think kids with the mitochondrial autistic subtype could be a very large sub population that can encompass these other subtypes.

The symptoms of Mitochondrial disorders are very broad and manifest in a population as a spectrum.

Symptoms include GI issues, seizures, developmental delays, hypotonia, neuro-psychiatric disturbances etc..

A distinction should be made with regard to "inherited" mitochondrial disorders (rare) and Mitochondrial dysfunction (not rare).

According to the United Mitochiondrial Disease web site many of the symptoms of mitochondrial disorders parallel the autistic symptoms that are showing up in these kids.

Here's the symptoms they list

About Mitochondrial Disease symptoms

Diseases of the mitochondria appear to cause the most damage to cells of the brain, heart, liver, skeletal muscles, kidney and the endocrine and respiratory systems.

Depending on which cells are affected, symptoms may include loss of motor control, muscle weakness and pain, gastro-intestinal disorders and swallowing difficulties, poor growth, cardiac disease, liver disease, diabetes, respiratory complications, seizures, visual/hearing problems, lactic acidosis, developmental delays and susceptibility to infection.

United Mitochondrial Disease web site- Symptoms

http://www.umdf.org/site/c.dnJEKLNqFoG/b.3042177/k.D869/fontfont.htm

Dr. Bruce Cohen talks with ABC News Now - Healthy Life Dr. Tim Johnson-video

http://abcnews.go.com/Video/playerIndex?id=5573430

Dr. Bruce Cohen with the Cleveland Clinic sat down and spoke with ABC News Now - Healthy Life Dr. Tim Johnson on the new research done by Dr. Patrick Chinnery showing that 1 in 200 people born with DNA Mutation that can lead to mitochondrial disease. Click here to learn more about this landmark research.

Segment orignally aired August 13, 2008. Click here to view the video.

http://www.umdf.org/site/apps/nlnet/content2.aspx?c=dnJEKLNqFoG&b=3936471&ct=5831043