Do gut bacteria hold the key to determining the cause of schizophrenia?
APC Researchers in have put forward a radically novel view of the biology of schizophrenia and more specifically its genetic basis. Their work, which is funded by Science Foundation Ireland, has significant implications for the development of new treatment strategies for the disorder.
Schizophrenia is a brain development illness and one of the most devastating to affect young people. It usually begins in the late teens or early twenties, and tends to be a life-long condition in the majority of cases. The risk of developing the disorder is approximately 1 in 100 in the general population. However, if there is a history of schizophrenia in the family the risk rises significantly. Identical twins are more likely to share the disorder than non-identical twins. Interestingly, if children are adopted their risk of the disorder relates to the family history of the biological and not the adoptive parents, strongly suggesting that genetic factors are important. However, very slow progress has been made in determining the complex genetics of schizophrenia.
Prof. Ted Dinan and colleagues at the APC in UCC have published a paper on the genetics of schizophrenia in the influential journal Molecular Psychiatry. They argue that the genetic studies conducted over the past few decades have been less than productive in determining the underlying biology of the disorder and in helping develop new treatments. In the paper they re-evaluate the studies to date and put forward a radical alternative perspective.
Dinan and collaborators point out that there are over 100 times as many genes in the bacteria within our intestine as exist in our cells. Many of these genes play a fundamental role in brain development and function. In their laboratory they have found that animals raised in a germ free environment, who have not been exposed to bacteria, show similar social interaction to that observed in schizophrenia and recent studies indicate that antibiotics may help alleviate some symptoms. Minocycline, which is frequently used to treat acne in teenagers has been found to impact on symptoms such as delusions and hallucinations together with social withdrawal. To date there has been little effort to explore intestinal bacterial genes in patients with the disorder. Dinan’s group is currently focusing on this approach with a view to developing new and more effective treatments. They draw a parallel with the gut disorder peptic ulcer disease, which like schizophrenia tends to run in families. No amount of genetic testing of patients would have found the cause of this disease which is ultimately due to genes in the bacteria Helicobacter pylori.
Link to paper: