Mental illness, very simply put, is a state of emotion, cognition or behavior that is relatively pervasive and interferes in a person's ability to function in society.
Correct. Therefore, I'd say it follows that mental illness is largely defined by society and the functional requirements thereof.
Different societies (as well as individuals within a society) can disagree on what constitutes a normal vs. pathological level of functioning. That's not to say there aren't certain cross-cultural commonalities of how psychological distress is experienced. Madness, which is characterized by abnormal patterns of behavior, has been recognized by virtually every culture throughout history. However, while every culture finds some behaviors abnormal or unacceptable, the definitions can vary quite dramatically. Optimal functioning is selected for and defined by the particular needs of a society.
For example, it would be absurd to diagnose ADHD in an agrarian society. Until optimal functioning became defined as quiet classroom attentiveness for many hours a day, hyperactive behavior had not been pathologized. And not until incentives were in place for pharmaceutical companies, was the process of pathologization completed.
Mental illness is not only defined in a culturally-specific manner; its manifestations are also culturally dependent. A good example is anorexia nervosa. While the disorder has long been identified by Western society, it is a relatively new phenomenon in China and Japan. As the ideal body image becomes thinner, there is a corresponding increase in the prevalence of the disorder.
Again, I am not arguing that there are not commonalities in the experience of psychological distress among individuals living in different societies. However, I am saying that the dichotomous cut-offs defined by the APA reflect the culturally-specific views of what constitutes mental illness by Western society. Therefore, our diagnostic criteria are not universally valid.
kugel said:
In a simple, and sarcastic, sense, "by consensus."
Just like it is society that defines any disease, whether society defines it actively (through legislation or open and public debate) or through inaction (allowing it to be defined by small groups which have specific agendas, like a medical specialty organization or a lobbyist group or a pharmaceutical company).
Is hypercholesterolemia a disease? It has no symptoms! It is really not a disease in the classic sense at all. It's just a risk factor for other diseases. But it has been defined as a disease by medical groups, gotten government blessing (ICD coding and MediCare payments for treating it) and pharma makes billions on it every year.
Is dementia a disease or just the inevitable course of aging, though some get it earlier in the aging process than others?
I see what you are saying. The term "disease" has no unambiguous, generally accepted definition.
However, it is the "disease realism" model that has predominated in psychiatry, with Emil Kraepelin as an early staunch advocate. This view states that a disease is "an objectively demonstrable departure from adaptive biological functioning". Therefore, clinical signs and symptoms do not constitute disease. It is not until the causal mechanisms are clearly identified that we are really speaking of a disease.
Debating what the normal range for HbA1c values should be is altogether different from determining what constitutes normal function or behavior. The former is based on risk for various complications and/or mortality. As our knowledge of risk factors and outcomes has increased, the optimal range has been adjusted accordingly. Behavioral norms, on the other hand, are much more subjective and are for the most part culturally defined. Perhaps this is most strikingly true for the personality disorders, but I believe it holds for many Axis I diagnoses as well.
I agree that defining dementia is somewhat arbitrary … a decrease of how many points on the MMSE? However, few would argue that Alzheimer's disease is not an organic brain disease. Imaging and post-mortem studies reveal relative consistency in underlying pathology. This is not the case with the majority of psychiatric conditions. In schizophrenia, for example, it seems that the only reliable post-mortem changes identified thus far are attributable to long-term dopaminergic blockade. There is no consistent underlying pathology.
I think it's fair to say that schizophrenia, if not a true disease, is a term that describes a heterogeneous group of manifestations that are at least loosely clustered. Perhaps, for certain rare subtypes, etiologies will be discovered. However, I find it exceedingly unlikely that the bulk of diagnoses (all psychiatric diagnoses) will be explained by reducing mental illness to neurochemical deficiencies or other biological etiologies.
To better illustrate the difference between medical and psychiatric "diseases," let's look at the disease-centered model of drug action, which has worked well in medicine. Drugs have been developed that act on the underlying causes of a disease or that reverse the pathology of a medical condition. Penicillin directly targets the organisms responsible for syphilis. Insulin works directly on the process that leads to symptoms, albeit not on the original pathology.
This model fails for many psychiatric diagnoses. Taking a psychiatric medication is not like taking insulin for diabetes. Antipsychotics do not work by correcting chemical imbalances as insulin works by correcting a metabolic derangement. Antipsychotics, like other psychiatric medications, are first and foremost psychoactive drugs. They create abnormal brain states – altered states of consciousness – and the therapeutic value is determined by the subjective state that is produced.
I may be going on a tangent, but my point is that psychiatric disorders (as well as a number of medical disorders) are not diseases in the traditional sense, and psychiatric treatments are not the disease-specific treatment that they are proposed to be.
sluox said:
The other fact to consider is that while you could potentially "define" a new mental illness that is "culturally specific", even in psychiatry there are phenomenologies that are less culturally sensitive. For instance, major depression, bipolar disorder, primary psychotic disorders, etc. perhaps there are different description and classification of these illnesses, the objective entities have always existed throughout history and in all cultures. "Madness" is a universal phenomenon, just as cancer, stroke and aging. So as a society we can refine the nosology of illness but it's simply a description of nature.
This is to say, psychiatry is to a large extent an objective science. We don't create entities arbitrarily or creatively for whatever goals the society has--at least that's the mainstream interpretation. There are other philosophical interpretations of psychiatry, of medicine, of science, and we don't necessarily need to go into it right now.
Interesting post.
I agree that it is society that "refines the nosology" of mental illness; however, I believe that psychiatry erred when the DSM-III was adopted, due to the creation of false dichotomies in an attempt to appear more respectable as a medical profession. While "madness" may be a universal phenomenon, the current nosology is not well supported empirically. As Kenneth Kendler states, "gene discovery in psychiatry is, on its own, unlikely to allow us to ‘carve nature at its joints,' thereby validating categorical psychiatric diagnoses" (Am J Psychiatry 163:7, 1138). The same goes for neuroimaging or any other biological test in psychiatry. The current nosology is deeply flawed and at least in part maintained in contradiction to available evidence by various powerful interests.
It's likely that many psychiatric disorders merge into others with no natural boundary in between. If we are giving an accurate description of nature, there should be what Kendler calls "zones of rarity." For example, attempts to demonstrate natural boundaries between major depressive disorder and normality have consistently failed. Instead, studies have demonstrated that the genetic basis of anxiety and depression are very similar, if not indistinguishable. What exists is a spectrum. The same goes for schizophrenia, psychotic affective illness, and a spectrum of other disorders, including szhizotypal/paranoid personality disorder.
Also, I'd argue that we do create entities arbitrarily. If we measured other dimensions of performance and behavior, perhaps we could pathologize individuals that score low on creativity testing. All we need is an effective on-patent treatment.