Mental disorder is not unique to humans. Animals can get depressed, exhibit OCD and have anxiety just like we do. There is however, one kind of mental disorder which does not seem to affect the animal kingdom – schizophrenia.
What Is Schizophrenia?
Schizophrenia is a severe and chronic mental disorder which affects a person’s ability to think clearly, manage emotions and relate to others.
Symptoms can include hallucinations, hearing voices, confused thinking, false beliefs or delusions and being emotionally disconnected, among others.
Schizophrenia is usually diagnosed between the late teens and early 30s, and affects about 1% of the population. It can affect anyone from any culture or background.
There are a lot of misconceptions about schizophrenia.
Common ones include myths about split personalities or violent tendencies, when the truth is a person with schizophrenia is more likely to be withdrawn than anything else.
With the right treatment and support, schizophrenia is a manageable condition and people with schizophrenia can play an active role in family life and society.
Human Accelerated Regions – HARs
Dr. Joel Dudley and his team at Mount Sinai Hospital, in New York City, conducted research on short stretches of DNA.
The stretches of DNA changed rapidly in humans with evolution but remained constant in other species, including our nearest relative the chimpanzee.
Called HARs, these segments of DNA only exist in humans, probably because they have a specific benefit to us which we do not fully understand yet.
Since both HARs and schizophrenia are only found in humans, the scientists are questioning if the two are linked.
They found that HARs sit close to genes related to schizophrenia in the human genome. Too close to be a coincidence.
It is thought that these schizophrenia-related genes could be beneficial to us in some way, despite carrying the risk of schizophrenia.
While by no means conclusive, this would explain why schizophrenia affects such a large number of people.
Their research also found that schizophrenia genes associated with HARs are in areas of our genome which influences other genes, genes which are active in our prefrontal cortex – the area of the brain that influences high-level thought.
These prefrontal cortex genes are responsible for numerous important tasks, including one linked to the regulation of dopamine.
If dopamine goes unregulated it can cause the hallucinations, unclear thoughts and false beliefs that come with schizophrenia.
So Why Don’t Animals Get Schizophrenia?
There is a theory that human speech and language is related to schizophrenia and other disorders which impair cognition – such as autism and ADHD.
It suggests that the risk of these disorders is the price we pay for increased cognitive ability over other animals.
In the same way a high-performance PC will have more complex problems and malfunctions than a simple solar-powered calculator, our higher functions come at a price.
Dr. Dudley does state that the study was ‘not specifically designed to evaluate an “evolutionary trade-off“.‘
He goes on to say that ‘our findings support the hypothesis that evolution of our advanced cognitive abilities may have come at a cost – a predisposition to schizophrenia.’
Promising Progress and Pawed Partners
Research into this area looks promising, and hopefully it can provide us with new, more effective treatments for disorders that millions of people suffer with.
Although it seems we pay a price for our ability to speak and have complex thoughts, the silver lining is that our abilities may allow us to find a way to overcome the drawbacks.
We also must not forget that even though our furry friends are spared from schizophrenia, they can still suffer mentally. So, give your pawed partners a pat on the head, they might need it.