Friday, November 28, 2014

What is a mental "disorder" (part 2): two viewpoints on mental health problems

Largely, there are two conflicting views of mental health problems. Others might be listed, but these perspectives provide two images that are difficult to merge. Yet they may depict the same phenomenon. 

The first sees mental health problems from the viewpoint overlooking those very seriously affected. This group has lives in tatters due to their problems. They may be intellectually disabeled, suffer major psychotic disorders, paralyzing mood or anxiety problems or drink in a perfectly obsessive way to an early death. 

Noone has any difficulty saying that these persons are ill, nor that abnormal brain functioning is involved. General movements and posture are affected. It is debated whether this kind of mental illness is on the rise or remains constant across cultures and time, but anyway, prevalences are counted in single-digit percents. Proponenets of this perspective are often psychiatrists or nurses.

The other sees mental health problems from the viewpoint of total population epidemiology. This is a different sight. Problems are now present in tens of percents of the population, are gradual rather than categorical, change over time, often into new diagnoses or no diagnosis at all. Instead of disease-like conditions, diagnoses may be worded as liabilities or traits, and understood rather as extremes in the normal variation than as pathologies.

The problem is that psychiatry, in the era of criteria-based diagnoses, has put very little effort into studying how these two views relate to eachother. Instead, both have been voiced as if they were one and the same seamsless psychiatric truth. There is vast clinical experience to validate the first, in addition to it being common-sensical. There is more and better scientific data to validate the second.

Problems arise when knowledge from the first group is applied to large swaths of the population. Substance abuse is one example. Psychiatrists are eager to promote a medical model based on the very severe cases, but this conflicts with population-based data showing that most cases remit spontaneously, even without treatment. Maybe the same problem is present in our understanding of depression, hyperactivity, autism spectrum disorders, behaviour disorders and even psychoses?

This would explain why findings of brain abnormalities, genes and treatment effects in case-control studies tend to disappear when tested in population-based studies. And how 80% of the liability for a certain condition may be statistically referred to genetic effects, while the gene variants actually found only have very small effects. It also means that the severe cases may not be fully understood from the general population viewpoint, and that, if a clinical group with schizophrenia or autism have a certain sign in their genome or brain scans, it cannot be interpreted as a characteristic for the type of problem in the population.

It is tempting to propose that the general population liability for mental health problems expresses genetic polymorphisms, while the severe cases are due to mutations. In some very crude way this may be true, for example in autism, where mutations have been found in subgroups of cases who often also have mental retardation. And as polymorphisms are defined as being more prevalent than mutations, it would seem a safe bet. But as a general explanation, I think such analogies between genome and mental phenotypes over-simplify the complex causation of mental health problems. They also overlook how mental processes may be free, random, self-generating and the result of interactions with the environment.

In a forensic or moral context, the obvious existence of persons who have had their mental capacities for insight and action control destroyed by severe mental or neurological disorders should not be interpreted as a general lack of accountability in people with mental health problems. As health care staff, our aim should be to restitute health and responsibility. By stating generally that people with e.g. substance dependence or ADHD have no responsibility for their behaviour, we disserve large numbers of persons who deserve both praise and criticism for their acts.

Elegant plaidoyers of the first vs the second view are proposed by Allen Frances in "Saving normal" and by Jonathan Rottenberg in "The Depths". Both books are heartily recommended.

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