Numerous other terms, more or less synonymous with “mental disorder”, have been suggested, e.g. “illness” or “condition”.
"Clinically significant" may mean that the condition hampers the ability to "work and love" (Freud), i.e. to have meaningful occupation and relations, but also that the condition produces considerable suffering. Various definitions of mental (un)health have been proposed, but none is generally accepted.
“Disorder” is a broadly defined term. It indicates a lack of some sort of order but does not specify what that order is.
Is a mentally disordered person someone who in some mental aspect lies outside the variation contained in the central standard deviations of the normal curve? Or does (s)he fail to live up to an ideal, ordered, state of mind? Or does (s)he present symptoms that are qualitatively different from what is experienced by healthy persons (such as hallucinations, delusions, tics, or compulsions)?
All three definitions are open to justified criticism. Symptoms such as hallucinations are not limited to persons exhibiting other features of mental disorder (van Os, Hansson, Bijl & Ravelli, 2000). Dysfunction and suffering depend to a considerable degree on the environmental demands made on an individual, and deviance from the average may be both advantageous and disadvantageous (Baron-Cohen, 2000). The statistical approaches invariably include measurement problems.
Of course, this vagueness becomes most problematic when definitions of mental disorder are applied in courts of law, but they also haunt psychiatric research. We will therefore continue to go through definitional pit-falls and different systems of validating disorders in a few more posts. Next week, the two different views on mental disorders as illnesses in the medical sense vs. extremes of the normal distribution will be discussed.
This blog post is partly excerpted from the paper "Mental disorder is a cause of crime" I co-authored with Susanna Radovic, Christer Svennerlind, Pontus Höglund and Filip Radovic in 2009.