The untimely death of the talented and much-loved actor Robin Williams last week sent a ripple of sorrow around the world.

The announcement of a suicide is often followed by admissions of disbelief. How often do we hear it said that someone who has died "had so much going for him" or "seemed so happy when I saw her last week". Diff'rent Strokes actor Todd Bridges was roundly, and rightly, criticised for tweeting that suicide was "a selfish act". He swiftly apologised, but it's a relatively common, if ignorant, response to suicide.

We look for simple answers to a complex issue. The closest we come to understanding depression is by acknowledging that perhaps those of a creative bent, with their exotic, surreal lives and unique pressures, those "inner demons", are somehow more disposed to it, and to suicide, but this denies the reality of those in our midst who face an internal, daily battle. Depression is the colleague who seems quieter than usual. It's the man who sits opposite you on the train in the morning. It's your boss. Mental ill health can call at the door of any house. For years, campaigners have reminded us that in any given year one in four of us will be affected, yet the "otherness" of depression and other conditions persists.

Today in Scotland, two families will wake up to the living nightmare that begins when a cherished loved one takes their own life. Death by suicide is the biggest killer of young men aged 20 to 49 in Britain. That's more than road deaths and all the other dangers that face our young people.

The death of Williams prompted a wave of Twitter messages of condolence. However, despite all the exposure the virtual world offers, our communal conversation never seems to lead to a deeper understanding. Talking therapies and openness are part of the solution, yet despite being surrounded by multiple communication tools we are still in the dark.

Instead of the internet being used as a way to spread understanding, we are swept away on a tide of 140-character condolences from famous friends. Or worse, perverse trolling, where additional misery is heaped upon relatives. Then comes the dissemination of forensic details of the moment and means of passing. In the last few days mental health charities have strongly criticised some of the coverage of the death of Williams, stating that this in itself can lead to other deaths as surely as furnishing the vulnerable with a handbook.

As a society, when it comes to mental health, we still talk in terms of us and them; them being a small group of people, outwith our own circle, who are intrinsically different. "We" are alright, Jack. "They" are the horror stories on tomorrow's front pages.

Despite great strides made by mental health charities, this dangerous fallacy still persists. But everyone who has a mind has mental health. Just as we need to maintain our physical health and seek medical help when it falters, so we must accept that mental health needs maintenance. We are all on the spectrum of mental health. Some of us are blessed with strong support networks so that when tragedy strikes we can call on these precious human resources. But mental ill health is not exclusively about the fall-out from a traumatic life event. It can strike without logic or cause.

Some of the more invasive mental illnesses, such as bipolar disorder and schizophrenia, catch young people just as they blossom into adulthood. They strike irrelevant of academic achievement; they strike in the heart of a happy home, and can rob sufferers of everything that a physical illness might do. Unlike those physical conditions, however, they are often endured in self-imposed silence for fear of the negative reactions of others, which merely compounds the suffering. Perhaps, then, it is no surprise to learn that a diagnosis of schizophrenia can have an impact on life equivalent to that of quadriplegia.

For us to be truly inclusive and empathetic to those who are brought low by mental illness, we need to acknowledge our own vulnerabilities and admit that, at some point in our lives, any one of us could be felled by a bout of ill health. By doing this, we can create a society where it is safe for someone to come out and say: "No, I'm really not OK".