Why Don't Animals get Schizophrenia?

We see evidence of all sorts of traits associated with abnormal psychology in non-humans species, including separation anxiety in dogs, obsessive behavior in birds, and self-mutilating behavior in dolphins kept captive. One thing that we never seem to see in non-human species is psychosis and the big question here is: why is that?  Researchers know that humans have sections in our DNA called human accelerated regions (HARs) that were conserved in most species but underwent rapid evolution in human beings. HARs are regulatory regions and do not code for protein.The new question that came out of this was if HARs and Schizophrenia are both human specific, are they at all related? To answer this question team of researchers used the Psychiatric Genomic Consortium to look at the genomes of persons with Schizophrenia. What they found was the HARs and genes associated with schizophrenia were close by on DNA (closer than would be random chance) and that the HAR related genes associated with schizophrenia were under more positive selection than other genes related to schizophrenia. This lead the researchers to believe that these HAR genes are beneficial to us in some way, when they are not causing schizophrenia. To look further, the researchers looked at gene expression profiles and found that these HAR genes were regulating genes that were expressed in the prefrontal cortex were we do our higher level thinking and some were involved with the transmission of GABA, an inhibitory neurotransmitter highly linked to schizophrenia. The end conclusion is that as humans developed more complex neural pathways, we developed more complex things that can go wrong. As Bret Stetka said in his article "complex function begets complex malfunction".

The main article:
 —Stetka, Bret. "Why Don't Animals Get Schizophrenia (and How Come We Do)?" Scientific American Global RSS. N.p., 24 Mar. 2015. Web. 20 Apr. 2015. <http://www.scientificamerican.com/article/why-don-t-animals-get-schizophrenia-and-how-come-we-do/>.

The study about Schizophrenia:—
Ke Xu, Eric E. Schadt, Katherine S. Pollard, Panos Roussos, and Joel T. Dudley “Genomic and network patterns of schizophrenia genetic variation in human evolutionary accelerated regions” Mol. Biol. Evol. 2015 : msv031v1-msv031. 3 Feb. 2015. Web. 20 Apr. 2015.


Another similar study about Autism:—
Clarke, T. K., M. K. Lupton, A. M. Fernandez-Pujals, J. Starr, G. Davies, and S. Cox. "Common Polygenic Risk for Autism Spectrum Disorder (ASD) Is Associated with Cognitive Ability in the General Population." Molecular Psychiatry. Nature, 10 Mar. 2015. Web. 20 Apr. 2015.

By Sadina Videlock-Prentice