Discourse on "mental disorders"

It seems most studies might say that 60% of predisposition towards "having" a "mental disorder" is due to environmental factors and 40% might be due to genetics.

So if 60% of the cause of "having a mental disorder" is a due to the environment having an impact on an individual and only 40% is genetic on average, then is it not the environment that must change? What is it about these environmental factors?