I was unaware that I said it was something to be ashamed of.

However, most mental illness is the result of excessive stress piled on to a predisposition.

Very, very few people on this planet don't have a predisposition to one thing or another.

To live in countries (UK, US, and some others) which are highly stressful will generally result in mental illness.

Some years back, the official mental health site of the USA said that 25% of Americans had chronic mental illness and another 25% had episodic mental illness.

This is a result of several cultural perceptions which lead to excessive stress.