But the response to it has also sparked some genuine questions about how people treat, and think about, mental illness.

Sarah stayed on the drugs even though they seemed to make her feel worse, eventually hearing menacing voices telling her to kill herself and being given electroconvulsive therapy (ECT).

But some made a leap from saying antidepressants don't work by fixing a chemical imbalance, to saying they don't work at all.

This latest research looked at 17 studies and found people with depression didn't appear to have different levels of serotonin in their brains to those without.

Research suggests antidepressants work only a bit better than placebos (dummy drugs people are told could be the real thing).

Within that average is a group of people who experience much better results on antidepressants - doctors just don't have a good way of knowing who those people are when prescribing.

Prof Linda Gask, at the Royal College of Psychiatrists, says antidepressants are "something that help a lot of people feel better quickly", especially in a crisis.

But one of the authors of the serotonin paper, Prof Joanna Moncrieff, points out most research by drug companies is short-term, so little is known about how well people do after the first few months.

While there are risks to leaving depression untreated, some people will experience serious side-effects from antidepressants - which the serotonin study's authors say need to be more clearly communicated.

Since last autumn, UK doctors have been told they should offer therapy, exercise, mindfulness or meditation to people with less severe cases of depression first, before trying medication.

Serotonin plays a role in mood, so tweaking it can make people feel happier at least in the short term, even if they didn't have abnormally low levels to start with.

However, Zoe, who lives in south-east Australia and experiences both severe depression and psychosis, says rebranding depression as "distress" that would go away if we "just fix all the social problems" is also too simplistic and overlooks people with more severe mental illnesses.