The term "mental illness" applies to so many things that it's fair to think society has blame for some aspects of it. The pressure, scrutiny and general lifestyle of some is enough to drive them to the brink, life is stressful and sometimes it breaks people. It's worsened by how mental illness is demonized so nobody gets help.
This is true in many ways. Society has created the mental illness in some, by literally driving them crazy. It has created mental illness in others because of doctors, family member, friends, etc... diagnosing someone with a mental illness when they are actually perfectly sane. It happens all the time. It is society that has the mental illness.
I believe mental illness has become a far bigger topic than it has been in the past and I believe people talk about it far more openly than they have in the past. I think we have learned to label certain mental issues more clearly than we have in the past and I do believe society has caused trouble for many people.
While I do think that there is some credence to environmental factors contributing to the development of mental illness, I don't think it's something we can fully blame on society. If someone is predisposed to mental illness, then it's going to come out. The timing, or what triggers that timing, is not relevant.
No, society has not created mental illness in some people, because throughout history, there has always been a part of society that has been mentally ill. Even in primitive societies, and throughout Bible times, there have always been a few members of society with mental health issues. Even though society has changed a great deal, there remain a few that are mentally ill. This is not the fault of society.