Re: Welcome in the realm of mental illness...
Part of that is because mental illness remains a taboo subject for many, even in the 21st century.
My wife suffers from a bipolar disorder (for which she receives treatment) and also looks after children.
I once made the mistake of mentioning her condition to a close friend. His immediate reaction was: how can she be trusted to look after children? It really hurt to hear that, given that she is probably the best child care-taker on the planet, bar none. She receives nothing but praise from the parents.
Unfortunately, many people still operate with attitudes worthy of the dark ages. They fail to understand that conditions such as depression are often very effectively treated with medication and regular therapy. Sufferers can still lead productive, happy lives. Mental illness is often more successfully treated than many chronic physical ailments and with less side effects.
Sadly, you can't always treat people's ignorance about these issues and so the stigma remains very intense.