Autism and Schizophrenia, is there a connection?
Are Schizophrenia and Autism related? That is the question left on the minds of some parents and scientists. Now it’s the question left on my mind.
Several months ago my 11 year old son started having hallucinations. His hallucinations present as visual, auditory, and tactile. It’s become the ultimate trifecta of confusion and misery for him. His doctors are working on figuring out what is going on and how to handle it; however much like with everything else concerning Autism- the answers just aren't coming fast enough for me. The only solutions I have now is to do the research myself. What I found has left me a little bit shocked. You see, when my son was diagnosed with autism I never considered the comorbidities that can come along with an Autism diagnosis; likewise, once I did consider the comorbid disorders there was one that never crossed my mind: Schizophrenia. Nothing was ever said to me about Pervasive Developmental Disorders (PDD) and Child Onset Schizophrenia (COS) being related in anyway. Nope, I had to learn about that via google scholar.
The Studies concerning Autism and Schizophrenia
Child Onset Schizophrenia (the onset of psychosis before age 13) and Autism have been regarded as both related and unrelated over the years. To put it as the doctors at the Seattle Children's Hospital put it: "These disorders have at various times been regarded alternatively as closely related and as non-overlapping and incompatible."
So, which is right? Are they related or unrelated? After doing my research it seems to me that the two disorders are more alike than different in some ways and in others they couldn't be any more unalike. Let's find out what you think.
According to Judith Rapoport, M.D., Alex Chavez, B.S., Deanna Greenstein, Ph.D., Anjene Addington, Ph.D., Nitin Gogtay, M.D. [all of the National Institute of Mental Health] "Epidemiological and family studies find association between the disorders [Schizophrenia and Autism]." Epidemiological studies are actually often considered to be the cornerstone of public health. To have a study such as this come back positive for a correlation is mind-boggling to me. Their finding also show that 30-50% of PDD cases also have a comorbid diagnosis of schizophrenia by maturity. The fact that this isn't talked about more I find to be ridiculous! The links that have been found between the two speak volumes.
There’s a mouse study published that shows some of the links between PDD and Schizophrenia. During this study scientist essentially took a pregnant lab mouse and gave it a viral infection (the flu) using microarray technology. After birth they recorded the subsequent changes in the pinkies as pertaining to Autism and to Schizophrenia. According to this study there are significant upregulation of 21 genes and downregulation of 18 genes in the affected neonatal brain cell structure in both disorders. To break it down even further, these results also show for the first time that “exposing a fetus on day 9 of pregnancy to the flu leads to alterations in a subset of genes in brains of exposed offspring, potentially leading to permanent changes in brain structure and function.” Particularly in these areas:
- cytosolic chaperone system
- Bicaudal D
- aquaporin 4
- carbonic anhydrase 3
- glycine receptor
- norepinephrine transporter
- myelin basic protein
All this information and these 8 big names may look confusing. They were at first to me too. Basically this is telling us that prenatal viral infections affect areas from protein folding to neurotransmission in the spinal cord and brainstem, all the way to things such as enzymes that affect digestion to proteins that affect depression and empathy. The connection this all has to Schizophrenia and Autism? These are all shared changes between the two disorders. To this author these findings alone speak to a need to look further into the correlation between Schizophrenia and Pervasive Developmental Disorders.
In 1999 Danish scientist held their own study concerning Autism and Schizophrenia. In their case-controlled study they aimed at exploring the association between “perinatal factors, parental psychiatric history, socioeconomic status, and risk of autism.” The cases used 698 children, all with a diagnosis of autism. Likewise 95% of the participants also had a parent with a diagnosis of schizophrenia. In the end their analyses showed “no significant association between the risk of autism and weight for gestational age, parity, number of antenatal visits, parental age, or socioeconomic status.” To the contrary, their results did suggest that “prenatal environmental factors and parental schizophrenia are associated with the risk of autism.” So there’s an environmental and a genetic link between Schizophrenia and Autism. Let's take a look at some of the shared clinical symptoms between a Schizophrenia diagnosis and an Autism diagnosis.
The Clinical Similarities between Schizophrenia and Autism
Now, although these two separate diagnoses are just that, separate, they have quite a bit of clinical similarities. This is much like the likenesses between ADHD and High Functioning Autism, or in some cases Bipolar Disorder and Autism. The symptom and diagnosis comparisons between the two are found in these areas:
- Social withdrawal
- Communication impairment
- Poor eye contact
- Developmental delays
- Difficulty concentrating
- Difficulty finishing tasks
- Difficulty speaking
- In some cases, Hallucinations
That’s a lot of the same criteria isn't it? How do doctors classify this phenomenon? Is there a term? Actually there is a term for children whom fit into both worlds. In cases such as these, where children meet criteria for autism and other mental health diagnosis, scientist describe the children as having multiple complex developmental disorders. This is also called MCDD. In fact, you may find this as interesting as me: it’s believed that 64% of children with MCDD, that haven‘t developed hallucinations or psychosis in their childhood, will develop them by maturity.
Of course much more research needs to be done in this particular area. I must say that it does seem a little hard to ignore the fact that the correlations between Autism and Schizophrenia exist. The fact that it’s believed the 64% of children with more than one mental health diagnosis will develop hallucinations by maturity is eye-opening. We need an answer as to why this is. Why are Schizophrenia and Autism so closely related? Is it that they really are related and we have Schizophrenia classified wrong or is it that they are in fact completely different and we have the diagnostic criteria written to similarly? Whichever it may be thank goodness for the scientist that are working on it. We definitely need to get it sorted out because there are families out here waiting for an answer.
- Wiley Online Library: Prenatal viral infection in mouse causes differential expression of genes in brains of mouse progeny: A potential animal model for schizophrenia and autism
- ScienceDirect: Is schizophrenia on the autism spectrum?
- ScienceDirect: Autism Spectrum Disorders and Childhood-Onset Schizophrenia: Clinical and Biological Contributions to a Relation Revisited
- Oxford Journals: Risk Factors for Autism: Perinatal Factors, Parental Psychiatric History, and Socioeconomic Status