I don’t think the number of people with serious mental health issues has increased (they’re just more visible in communities now since the asylum closures), but it does seem there’s been an increase in anxiety and depression in the last few decades.
Could be for a number of reasons:
1.) Forcing us all together in open plan offices, indoors, for most of the year with very little exercise or variety to our days.
2.) Losing touch with seasonal changes e.g. eating for the season, moving more in the summer and resting/sleeping more in the winter.
3.) Social media/celebrity/always online culture and the pressure that goes with it, especially for young people. There's so much focus now on the cult of personality and appearances that we've forgotten the importance of character.
4.) The increasing gap between ‘the rich’ and ‘everyone else’. I suspect there is a strong correlation between the widening gulf in social mobility and the rise of anxiety and depressive disorders.
5.) We’re more aware of global issues than we ever have been – war, global warming, terrorism, violence everywhere. That can’t be good for the naturally anxious among us.
6.) We’re smarter than we ever have been. Again, there’s a correlation between intelligence and depression isn’t there? Maybe as we become more intelligent as a species we’re generally getting more depressed!
Perhaps there is an element of over-diagnosis and medicalisation of normal personality traits, but I’d be more inclined to think that we do have an increasing problem with mental health to the point it could almost be classed as an epidemic.
Our society is fundamentally broken and a lot of people are suffering because of it – physically and mentally.