Researchers from Neuroscience Research Australia (NeuRA) have presented new results about the role of testosterone in schizophrenia at the International Congress on Schizophrenia Research being held in Orlando, Florida.

They have found that, on the one hand, testosterone could be the trigger for the onset of schizophrenia. On the other, increased testosterone levels are associated with increased cognitive abilities of men with schizophrenia.

According to NeuRA's Professor Cyndi Shannon Weickert: "This research has raised the question, is testosterone beneficial or is it harmful?"

Schizophrenia has a worldwide prevalence of about one percent, and usually develops around the time of puberty. It is also slightly more common in males than females.

In a study using laboratory rodents, the researchers found that testosterone increased the brain's sensitivity to a brain chemical involved in motivation and reward, dopamine.

"We've found that adolescent increases in circulating testosterone may be a driver of increased dopamine activity in the brains of individuals susceptible to psychosis and schizophrenia," says Dr Tertia Purves-Tyson, a Senior Research Officer at NeuRA.

Dr Purves-Tyson is chaired a symposium on "Testosterone as a trigger for Schizophrenia" at the International Congress on Schizophrenia Research.

In another study presented at the congress, Dr Tom Weickert, a Research Fellow at NeuRA found that increased levels of testosterone in men with schizophrenia predicted higher cognitive performance of verbal memory, working memory and processing speed.

"This is the first study to show that high normal levels of testosterone can be beneficial to cognitive abilities in men with schizophrenia. Conversely, low normal levels of testosterone were associated with poorer cognitive function in men with schizophrenia; whereas no such relationship was present in healthy men. This suggests that testosterone is influencing brain activity and cognitive abilities in men with schizophrenia very differently from healthy men and warrants further study to understand the relationship," said Dr Weickert.

Health Canal