http://www.cchr.org/quick-facts/real-disease-vs-mental-disorder.html
Psychiatric disorders are not medical diseases. There are no lab  tests, brain scans, X-rays or chemical imbalance tests that can verify  any mental disorder is a physical condition.  This is not to say that  people do not get depressed, or that people can’t experience emotional  or mental duress, but psychiatry has repackaged these emotions and  behaviors as “disease” in order to sell drugs. This is a brilliant  marketing campaign, but it is not science. 
 “…modern psychiatry  has yet to convincingly prove the genetic/biologic cause of any single  mental illness…Patients [have] been diagnosed with ‘chemical imbalances’  despite the fact that no test exists to support such a claim, and…there  is no real conception of what a correct chemical balance would look  like.” —
Dr. David Kaiser, psychiatrist
 “There’s no  biological imbalance. When people come to me and they say, ‘I have a  biochemical imbalance,’ I say, ‘Show me your lab tests.’ There are no  lab tests. So what’s the biochemical imbalance?” —
Dr. Ron Leifer, psychiatrist
 “All  psychiatrists have in common that when they are caught on camera or on  microphone, they cower and admit that there are no such things as  chemical imbalances/diseases, or examinations or tests for them. What  they do in practice, lying in every instance, abrogating [revoking] the  informed consent right of every patient and poisoning them in the name  of ‘treatment’ is nothing short of criminal.” —
Dr. Fred Baughman Jr., Pediatric Neurologist
 “Psychiatry  makes unproven claims that depression, bipolar illness, anxiety,  alcoholism and a host of other disorders are in fact primarily biologic  and probably genetic in origin…This kind of faith in science and  progress is staggering, not to mention naïve and perhaps delusional.” —
Dr. David Kaiser, psychiatrist
 While  “there has been no shortage of alleged biochemical explanations for  psychiatric conditions…not one has been proven. Quite the contrary. In  every instance where such an imbalance was thought to have been found,  it was later proven false.” —
Dr. Joseph Glenmullen, Harvard Medical School psychiatrist
 “The  theories are held on to not only because there is nothing else to take  their place, but also because they are useful in promoting drug  treatment.” —
Dr. Elliott Valenstein Ph.D., author of Blaming the Brain
 “There  is no blood or other biological test to ascertain the presence or  absence of a mental illness, as there is for most bodily diseases. If  such a test were developed…then the condition would cease to be a mental  illness and would be classified, instead, as a symptom of a bodily  disease.” —
Dr. Thomas Szasz, Professor Emeritus of Psychiatry, New York University Medical School, Syracuse
 “I  believe, until the public and psychiatry itself see that DSM labels are  not only useless as medical ‘diagnoses’ but also have the potential to  do great harm—particularly when they are used as means to deny  individual freedoms, or as weapons by psychiatrists acting as hired guns  for the legal system.” —
Dr. Sydney Walker III, psychiatrist
 “No  biochemical, neurological, or genetic markers have been found for  Attention Deficit Disorder, Oppositional Defiant Disorder, Depression,  Schizophrenia, anxiety, compulsive alcohol and drug abuse, overeating,  gambling or any other so-called mental illness, disease, or disorder.” —
Bruce Levine, Ph.D., psychologist and author of Commonsense Rebellion
 “Unlike  medical diagnoses that convey a probable cause, appropriate treatment  and likely prognosis, the disorders listed in DSM-IV are terms arrived  at through peer consensus.” —
Tana Dineen Ph.D., Canadian psychologist