For a few days after Robin Williams' death, there was a lot of talk about depression. It was known that Williams suffered badly from it before he died.
Even though depression affects an estimated 100 million people around the world, it still seems to be a topic people are scared to discuss in the open. It's often written off as "someone else's problem".
Never mind, people say, that Williams appeared to be unusually quiet before his death. It seems that many people think offering help to someone in pain is somehow inappropriate, or even offensive.
We look to blame depression on almost anything - adolescence, mood, a bad day. It seems that we can't face reality. Less than 25 per cent of those suffering from depression are willing to seek professional help.
Yet the problem is widespread. A remarkable 44 per cent of the 2,000 local senior secondary school students surveyed in 2012 by Baptist Oi Kwan Social Service displayed signs of depression. But there are only 400 practising clinical psychologists in Hong Kong.
It is not necessarily fear of depression that leaves so many cases untreated, it is the stigma attached to it. This can take many forms: a pitying look if you dare to open up, a sense that you are being judged. But this taboo only serves to encourage sufferers to deny their pain. They must pretend to be "normal".
Depression isn't the only mental disorder to suffer such prejudices.
Anorexia is often blamed on vanity, and considered to be a "rich person's disease", or even worse, a cry for attention. It's talked about as though people choose to be anorexic. Many don't seem to consider it a real illness.
The problem is there is no easy answer to why someone may suffer from anorexia. It is complicated, and varies from person to person. It can be a result of lots of factors, including social influence.
Being skinny is considered something worth celebrating. You have to consider the huge pressure this puts on young people.
We live in a world where one alleged case of Ebola becomes headline news, but mental illnesses - which are also life-threatening - barely get a mention. Unlike Ebola, psychiatric illness often can't be as easily diagnosed.
Perhaps the greatest regret for John Keating, the English teacher portrayed by Williams in Dead Poets Society, was that he couldn't recognise the mental pain one of his students was suffering. It seemed like the world made the same mistake when it came to Williams.
We need to learn from this lesson. We need to give a voice to those who are struggling inside, and let them know that it is OK to admit they are in pain.
It is high time we put aside our outdated ideas about mental illness, and realise that a therapy session is no more scandalous than a doctor's appointment.