The sheer levels of mental ill health amongst people of my generation and younger is so off the scales that there have to be major external causes, I suspect a combination of social, political, cultural and economic failure creating a perfect storm of mental fragility.

I don't think it's just that mental illness is more acceptable to talk about or better understood - all the usual trite mantras. Despite the apparent peace and prosperity of modern western culture there must be things wrong with it that weren't during far more catastrophic times

Mental illness can have complex causes, but it's the simple things that are more likely to cause mass mental illness. Despite everything we're still animals, and like animals we will prosper in the right environment and deteriorate rapidly in unsuitable environments.

Although humans are the most adaptable animals, and that adaptability is primarily mental, we can mistake our relative plasticity for an infinite fluidity. We risk treating ourselves like abstractions or automatons (and that comes down to the same thing).

Put very simply, we're social (indeed as Aristotle says political) animals that are not in any way psychologically self sufficient, we only really cope well in communities of about 100 or so, and what we need from a house and a neighbourhood is also fairly fixed.

We certainly aren't built to live in isolation, or to socialise virtually, to live for long periods in tiny rooms and apartments, to look at screens for hours at a time, to spend two hours a day commuting etc.

Although most (perhaps every) mental illness is as complex as the person who has it, complex problems can arise from simple causes. Our ability to navigate ordinary mental challenges, and even serious traumas, is severely damaged by living in unsuitable conditions.

Quarantine is a unique intensification of that, but it is also exactly that - an intensification, not just an interruption. We were already more isolated, more online, not seeing friends or dating as much, we were already stuck too much indoors in too small rooms and apartments.

A lot of people my age feel trapped by their own minds, believing (as society encourages them to) that the only thing standing between them and love, wealth, fame, happiness is their own lack of mental fortitude and determination. But it's not that simple.

Poor mental health is imposed by living in an unhealthy way, and contrary to the individualistic mantra of self-improvement, the individual lacks the capacity to become healthy on their own. Becoming a gym rat or hitting the books won't necessarily produce good mental health.

But if the problem of an unsuitable environment for the human mind is relatively simple, the reasons again explode out into complexity. All societies in history have tried to produce a suitable environment for mental as well as physical survival, something has gone badly wrong.

At some deep level human society must have ceased to be about our psychic wellbeing, the priorities that have guided every society good or bad throughout history have invisibly shifted, and we are no longer in a 'human' society at all. Surprise! Post-humanism is already here.

It's not that every past society was benevolent and wanted to take care of everyone (that much has varied) but that in order to function materially, societies had to function psychologically. By whatever mechanism, modern politics/economics does without that (or far less of it).

This is not a council of despair however, once we know what it is that we need, and realise that society is no longer designed to provide it, we have both the beginnings of a way forwards and a personal source of mental strength.

It is very hard to stand amidst an apparently happy and successful culture and feel yourself alone, feel that you SHOULD be happy. But once you realise you are in the midst of an invisible catastrophe, you are no longer alone, and no longer responding inappropriately.

In terms of the political, social and economic changes needed to correct matters it is not as easy as driving directly at sanity - a lot has gone wrong and a lot had to go wrong to get to this point. But knowing what a mentally healthy environment looks like is a vital first step