No basis to chemical imbalance theory

I refer to the article “A persistent social crisis that is not all in our heads”, in which some of my thoughts were mentioned (Irish Examiner, September 21).

In this article, psychiatrist Dr John Hillary, director of communications of the College of Psychiatrists of Ireland, says: “I don’t believe the chemical-imbalance theory is still widely believed in Ireland”.

Dr Hillary is incorrect. During talks I have given on mental health, in recent weeks, 90% of audience members had been told that brain-chemical imbalances (eg serotonin) are a feature of depression.