Below is an excellent review of the book you are promoting was published in 1984. In fact at Amazon about 50% of the reviewers had similar opinions. You might also be interested in the fact that Szasz also changed his mind about this topic during his career.
The real cause of mental illness is trans-mediumship. You and everyone else has the ability to allow other beings, both in and out of body to enter and use/control your reality. It is what's behind multiple personality disorder and many other afflictions. An excellent examples is when you do or say something and you immediately tell yourself "why did I just do that?" It's because you as spirit weren't grounded and you as spirit were somewhere else while another being was taking control of your reality. Charles Manson, Thomas Edison, George W. Bush are but a few good examples of trans-mediums. You can channel "good" entities and "bad" entities - it makes no difference.
Learn grounding and you the eternal spirit can come in and control your reality the way you desire and not the way that others desire for you.
http://www.amazon.com/The-Myth-Mental-Illness-Foundations/product-reviews/006...
The more astute may wonder what Szasz makes of those inconvenient people who report hallucinations, delusions, agonizing depression, etc., etc. Being a deeply compassionate and humanitarian person, Szasz simply accuses them of malingering (yes, he actually says this). He appears to think that people with schizophrenia, depression, bi-polar disorder, and so forth should just "pull themselves together". I found myself wondering if Szasz had ever actually met, let alone listened to, anyone with a mental illness.
Yes, psychiatry, like other forms of medicine, often needs criticism, and has a history of abuse of power behind it. But no-one believes that the solution to abuse of power in other forms of medicine is to declare that bodily illnesses are a "myth" invented by doctors, and that those who complain of broken legs are malingerers. I can only assume that Szasz's fame is due to a stunning amount of popular ignorance and misinformation about mental illness. Having experienced a mental illness (clinical depression) myself, I have to say that Szasz's book adds insult to injury.
I have not red Szasz's book, but I also believe that mental illness does not exist. But this is a question of definition. Most people understand the term to mean literally "an illness of the mind", and as such this is a illusion. If we have a biochemical disorder that interferes with the synthesis of feel-good neurotransmitters - such as serotonin - then we are not going to be happy and content but these feelings are the results of a physiological illness and not a "mental Illness".
It is quite common in medicine to confuse symptoms with causes.
People find it much easier to accept that Schizophrenia and Bipolar Disorder are physical diseases. But most people find it difficult to believe that depression, anxiety attacks, Post Traumatic Stress Disorders PTSD, or OCD are physical diseases. Most of these have powerful psychological consequences and hence are seen as "mental" rather than physiological.
The traditional professions dealing with "mental Illness" - such as psychiatrists and psychologists - have an ambivalent view of mental illness. Psychiatrists believe that it is physiological; otherwise they would not be prescribing drugs. But drugs are so ineffective in "curing" "mental illness (see here), that they have to refer their patients to "psychologists - who mainly believe that mental illness is "psychological" problem, which also is a misconception.
There are in fact many "silent diseases" that can cause "mental illness". Fortunately the most common silent disease affecting our minds is hypoglycemia, so that depression, anxiety attacks and a host of other common mood disorders (classed as "mental illness") can be treated without recourse to drugs and/or psycho-babble. See Gyland.
Thus yes, mental illness does not exist, but certain diseases that affect our mind do exist. It is a matter of people becoming more educated as to what causes "mental illness". This is what this web site is all about.