The reason why it seems celebrities are more vulnerable to depression is a phenomenon called the availability heuristic. It means that we use mental shortcuts to assess the frequency of events by how readily we can recall them, how easily available the information is to our memory. Because we are constantly bombarded with celebrity news, including the stints they spend in rehab centers, we assume that more celebrities suffer from depression and commit or attempt suicide than the rest of us.

What we can conclude from Williams' suicide is that a sharp increase in suicide rates, often in connection with severe depression, is part of a trend among Americans of his generation. According to a 2013 report by the Centers for Disease Control and Prevention, there has been a substantial increase in the suicide rate among middle-aged adults in the US.

The 63-year-old Williams fits into a troublesome suicide demographic. The age-adjusted suicide rate among adults between 35 and 64 years in the US increased from 1999 to 2010 significantly in terms of statistics, according to the CDC.

A study published in the September 2014 issue of Social Science and Medicine found a strong positive correlation between unemployment rates and total suicide rates over time in US states. Other studies show that some of the buffers which may have mitigated suicide among Williams' baby-boom generation - religious affiliations and close family ties - have broken down, thereby contributing to the increase in the suicide rate.

However, we should reject simplistic explanations about celebrity depression and suicide. There is no larger message to be gleaned from Williams' death than that he was a troubled man who nevertheless contributed a great deal to many lives.

The author is a psychology columnist.