What is the point of an antidepressant after the serotonin hypothesis was debunked?

Between 2021 and 2022 8.3 million adults in the UK were prescribed an antidepressant (1) and 83.4 million prescriptions were written for antidepressants for adults.  For children and adolescents almost 12,000 were prescribed antidepressants with 180,000 prescriptions written.  Both increased from the previous year, adults by 5% and children by 8%.

What is the serotonin (5-HT) hypothesis of depression?

I am almost certain that most people are aware that a hypothesis exists that says people experience depression due to a chemical imbalance.  This hypothesis originated almost 60 years ago and posited that a serotonin deficit in the brain caused depression (2).  This hypothesis resulted in the development of drugs designed to improve uptake of serotonin to cure people from depression.

Has the serotonin hypothesis been proven?

The simple answer is, no.  Actually, it has pretty much been disproven.

In 2022, Psychiatrist Joanna Moncrieff and her colleagues at University College London, and various other universities in the UK and abroad, published their umbrella review of reviews looking at the evidence for the serotonin hypothesis of depression and found that there was "no support for the hypothesis that depression is caused by lower serotonin activity or concentrations."  

They did, however, find that long-term use of antidepressants may reduce serotonin concentration. 

It really does beg the question: why are these drugs still being handed out so readily?

You can read the paper here: www.nature.com/articles/s41380-022-01661-0%3C, if you're interested.