Ethnicity may play a role in how people respond to antidepressants, with new research showing that those of Chinese background are more sensitive to the medication than Caucasians.
Researchers say the finding could have important implications for the way in which medication is prescribed, and its effects understood.
In a pilot study, Chee Ng, a senior lecturer in psychiatry at Melbourne University and a consultant psychiatrist at the Melbourne Clinic, studied the effects of the antidepressant Zoloft (sertraline) on 20 people of Chinese heritage compared with 20 of Caucasian background. All were depressed.
Following the patients over two months, he found that the Chinese patients responded at lower doses of the medication than the Caucasian group. Dr Ng said the difference was probably explained by genetic factors affecting how the body metabolised and responded to drugs.
He presented his findings this year at the World Biological Psychiatry Congress in Sydney.
The results may help unravel why people respond differently to particular types of antidepressants. Trial and error is often required to find the drug that works for a particular patient.
"This is a very clear example that you can't just assume that a drug at a particular dose would suit everybody," Dr Ng said.
Cultural elements may also be important in looking at responses to drugs — for example, the types of food a person eats.
Beyondblue clinical adviser Ian Hickie said the direction of the research was welcome as little was understood about the relationship between antidepressants and ethnicity.
Genetics was the key, he said, either in the way the body metabolises medication through the liver and into the bloodstream or the effect of medicine on the brain.