As a conference on violence opens, Alan Thomson looks at research into the topic
DRUGS to control levels of human aggression and violence could soon be developed, say researchers from King's College, London.
Tony Cleare, senior clinical research fellow in psychiatric medicine, is studying the effects of serotonin - also known as 5-HT - and the male sex hormone testosterone, on human aggression levels.
He is working towards identifying the precise roles of 5-HT receptors in the human brain. If this can be done, it should be possible to design drugs to turn these receptors on and off and so control aggression levels.
Earlier research has shown that aggressive people generally have low levels of serotonin. Simply increasing levels has mixed results due to the complexity of the interaction between the receptors and their sensitivity to serotonin.
Dr Cleare has noted that it is already possible to boost serotonin artificially by drugs such as Prozac, and naturally by foods such as bananas, walnuts and Brazil nuts. Research by others has found corn to be low in serotonin producers.
Another area of research involves testosterone therapy for people who are naturally deficient in this hormone. Low levels of testosterone can cause physiological problems, but giving these patients testosterone can have negative side-effects such as sexual and physical aggression.
The aim is to be able to identify people at risk from testosterone therapy. It is unclear whether testosterone causes increased aggression, the violent behaviour is already in these people, or the changed behaviour is a bad reaction to the hormone.
Dr Cleare has started trials using testosterone and placebos administered by injection and skin patch to see if there are any differences in behaviour.