See the short introduction to these essays and the rest of my sociomedical essays here.
The average person does not know much about psychiatry or mental illness. He will probably know depression, manic depression (nowadays known as bipolar disorder) and schizophrenia, which he will probably confuse with multiple personality disorder (properly called dissociative identity disorder). What the layman understands is that modern psychiatry and treatment for mentally ill is incredibly effective and compassionate.
Mentally ill patients are no longer treated like animals and no one is forced to undergo quack treatments or dangerous, ugly therapies like insulin shock. Instead we have crisis therapy, peaceful asylums of tranquility, and hotlines where people can always talk about their inner feelings with a professional. And medications, of course. Whether the problem is grief, relationship issues, or worry about money, one of these treatment modalities can be used to solve it.
The main criticism towards psychiatric diagnosis is that it medicalizes and pathologizes aspects of normal life. One of the most criticized aspects of modern psychiatry is the way even trivial conditions are made into illnesses to be treated. Such controversial conditions include personality disorders, some phobias, ADHD (which technically is not a psychiatric but a neurologic condition), even depression. Unlike PMS, its more serious form PMDD (premenstrual dysphoric disorder) is considered a psychiatric condition, even though it also has physical symptoms.
It is not uncommon for a person to get different, often conflicting diagnoses from different shrinks. In some cases a single shrink may present the patient with a bunch of diagnoses, sometimes a list that would sound suspicious even to a layman. A seemingly stable patient can be told they have schizophrenia, bipolar disorder and perhaps even a personality disorder to boot. This makes one question who is saner, the patient or the doctor.
Those compare pretty well to the mental diagnoses of the past, such as hysteria, whose name derives from hystera, the uterus. Hysterectomy was used as a treatment. Another one was drapetomania, a label given in 1851 to the purported mental illness which made slaves want to escape. Whipping and amputation of toes were suggested as the most effective treatments.
One of the reasons why psychiatry is criticized is the imprecise nature it uses for diagnosing patients. Most psychiatric illnesses can only be diagnosed based on the information reported by the patient. Many psychiatric problems do show up in some clinical tests such as brain scans, but only rarely in laboratory tests. Yet many treatable medical illnesses causing psychiatric symptoms would be detected in such tests - if they were performed, which very rarely happens.
The DSM-IV (Diagnostic and Statistical Manual of Mental Disorders) is the current handbook of psychiatry based on which psychiatric diagnoses are made. It is full of controversy, which is not surprising considering how subjective the selection of diagnoses and illnesses is. The definition of a "healthy" psyche does not exist, though the same goes for medicine as well, there is no definition of a healthy person.
The concept of personality disorders in particular tends to irritate people. How can a personality be disordered? Personality disorders, like many other mental problems, are not really on/off switches but a spectrum. One should keep in mind that personality disorders were defined long before psychotropic medications even existed (and they are considered to respond poorly to medication, anyway), so unlike with some other conditions you cannot really blame the greedy pharmaceutical industry for inventing them.
The main problem with DSM-IV, however, is that it contains diagnoses, or descriptions of symptoms, which in psychiatry are normally taken to equal illnesses. For example depression is considered a diagnosis and thus a distinct condition in itself. Yet depression can be caused by illnesses as various as pancreatic cancer (even years before any other symptoms) and hypothyroidism. The former is very rare, but the latter affects several per cent of the population, frequently causes depression and often remains misdiagnosed.
The whole point of defining an illness is that illnesses cause problems to people. In case of mental illness the person might not always be bothered, but the people around him might be. A quirky personality or behavior is not sick, if it does not cause anyone any harm. An illness, on the other hand, can cause a lot of suffering and usually that can be relieved in some way, which can but does not have to mean medication.
We all probably agree unethical to try to goad people into feeling bad about something that is not causing them any problems, but sadly the industry has a different view. This is one of the reasons why I am strongly against advertising prescription medications to the general public. In most countries it is illegal, but in the United States antidepressants are advertised between lipsticks and potato crisps.
There are bigger problems than medicalization, though. Many people do not have a choice in accepting psychiatric "treatment", whether they are actually mentally ill or not. Sedatives and antipsychotic drugs are commonly used to make people easier to handle, especially in institutional context, such as nursing homes and places where disabled people are treated.
Antidepressants and antipsychotic drugs have turned into wonder drugs which many doctors believe are appropriate first-line treatments for just about any condition, from poor sleep to stomach pain. Some day psychotropic medications may be available without prescription. Then again, this is not too far from the current situation, where you can get an antidepressant prescription based on a five-minute consultation from a general practitioner. Do you want fries with that?