Friday, 5 November 2010

What is mental illness?

Illness is like the street you've driven down your whole life. So familiar you've never bothered to look around. We've all experienced illness, either first-hand or via someone we know, but rarely do we stop to wonder what it really is.

You might say it's when something mental or physical isn't working as it should be. But then who is to say how things should be working? This is easier to answer in relation to physical health, but still tricky. Pain, a loss of ability, a shortening of life expectancy, perhaps? These criteria seem far from satisfactory. Pain is highly subjective and can be triggered by mundane ailments like toothaches or stubbed toes - are they really illnesses? Loss of ability seems more objective, but is surely only a necessary rather than sufficient criterion. After all, temporary fatigue and age both cause a loss of ability. Similarly, driving cars fast and other dangerous hobbies will likely shorten your life. These philosophical conundrums are magnified when it comes to mental illness. When does a hobbyist collector become a compulsive hoarder? How tightly do the shackles of shyness have to constrain a person before he or she is considered ill? What if the solitude of the social phobic allows them to pen great poetry or novels - is that adaptive or maladaptive?

The psychiatrist Dan Stein at the University of Cape Town and five others have tackled these issues and more in an editorial for the journal Psychological Medicine. Their approach has been to consider the definition of mental disorder stated in the fourth edition of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM), and to recommend modifications to it to be used in the forthcoming fifth edition, for which they are Work Group members.

Stein's team propose that a mental disorder has five features. First, it is a behavioural or psychological syndrome or pattern that occurs in the individual. This emphasis on the individual rules out dysfunctions that exist at the relationship or group level. Interestingly, they acknowledge that this causes problems for the DSM IV diagnosis of Shared Psychotic Disorder (or Folie à deux) in which delusions are passed from one person to another.

Second, the symptoms of a mental disorder are clinically significant distress (e.g. a painful symptom) or disability (i.e. impairment in one more important areas of functioning). Here they explain that 'clinically significant' is meant to distinguish from 'milder distress or difficulty in functioning that may not warrant clinical attention'. They acknowledge that clinical significance is tricky to 'operationalise', but argue that it 'remains useful in differentiating disorder from normality'. Readers will notice that this point doesn't really help us distinguish between personality traits like shyness and disorders like social phobia - it merely acknowledges that somewhere a line of severity is crossed.

Third, the behaviour or symptoms must not merely be an expectable response to common stressors and losses (e.g. the loss of a loved one) or a culturally sanctioned response to a particular event (e.g. trance states in religious rituals). Similar to the last, this point is also intended to help prevent the medicalisation of psychological reactions that are an expected part of life. However, Stein's team acknowledge this is murky territory - for example, they point to the contentious boundaries between 'normal and pathological bereavement.' Also, so-called 'normal' reactions to distress are often associated with increased risk of more serious problems later on - in other words, from a clinical point of view they shouldn't be ignored.

Fourth, a mental disorder must reflect an underlying psychobiological dysfunction. This is an acknowledgement that all illnesses of the mind have an underlying neural correlate. Meanwhile, the 'dysfunction' described here can be interpreted either in evolutionary terms whereby some faculty is not working as it evolved to, or in terms of statistical deviance from what's normal according to the client's own background and future goals. Neither is without problems. Evolutionary interpretations tend to be speculative, and what counts as dysfunctional is subjective and influenced by context. Stein's team give the example of living in a dangerous urban area 'where it may be adaptive to join a gang, but where this requires participating in behaviours listed in the diagnostic criteria for conduct disorder.'

Fifth, to be a mental disorder, Stein and his colleagues say a person's behaviour or symptoms should not primarily be a result of social deviance or conflicts with society. This is yet another safeguard against over-pathologising behaviour. The criterion is required, Stein's team say, 'because psychiatric diagnoses have been used for political purposes in the past and potential future misuse cannot be ruled out'. Indeed, one need only consider the fact that homosexuality was included in the DSM until as recently as 1973 to see the inappropriate influence of social mores on psychiatry.

Finally, Stein and his co-authors outline several further points for DSM 5 to bear in mind when considering what constitutes a mental disorder, including: that the potential benefits of adding a condition to the new DSM should outweigh the potential harms, and that any new diagnostic category should be clinically useful - that is: 'facilitate the process of patient evaluation and treatment rather than hinder it.'

As you can see from these highlights, there are many grey areas when it comes to defining what constitutes a mental illness, especially in relation to judging what counts as abnormal distress or dysfunction. As the authors conclude, the basic position (acknowledged in DSM IV) that mental disorder cannot be 'precisely operationally defined seems ... to be basically correct.' However, on a more optimistic note, Stein's team further argue that the classification system can improve over time as the scientific knowledge base progresses. 'Disorders are more than mere "labels",' they conclude, 'and progress towards a more scientifically valid and more clinically useful nomenclature is possible.'

What do you think? Do you share their optimism?

ResearchBlogging.orgStein, D., Phillips, K., Bolton, D., Fulford, K., Sadler, J., and Kendler, K. (2010). What is a mental/psychiatric disorder? From DSM-IV to DSM-V. Psychological Medicine, 40 (11), 1759-1765 DOI: 10.1017/S0033291709992261

Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.

Further reading on the Digest blog:
Are mental disorders real?
New data suggests one in two of us experience mental illness in our life-times.
Psychotherapy has drug-like effect on the brain.

This post is an invited contribution to a mini blogging carnival on the topic 'What is psychopathology?' hosted by The Thoughtful Animal blog.


  1. My thoughts to the 5 main points are:

    1. Whilst it is suggested it is at the level individual and so an explanation as to why it is keenly felt by the individual and why individuals will display and react to mental illnesses differently, it doesn’t rule out shared dysfunctions within relationships or groups as they may still occur, for instance, to learnt behaviour.

    2. When you categorise you need lines to cross, this ‘need’ to categorise could be exactly why disorders exist and why there is stigma attached to them. They can make individuals feel and behave in an unhealthy and unhelpful way.

    3. I would say it is when the behaviour becomes unhealthy. Some depressive behaviour can be adaptive and a healthy behaviour if a short term response as it gives space to regroup and reflect, however they can easily become maladaptive and unhealthy. Why these behaviours are employed in the first place and kept going could be linked to learnt behaviour.

    4. Agree there must be a genetic component, however if the genetic component is triggered will depend on environmental factors. For example a low threshold to anxiety may not be triggered if brought up in a supportive environment. However someone in with a high threshold to anxiety may become anxious/depressed if the environment is not conductive to the individual’s own development, but may take longer to be exhibited than for someone with a lower threshold. To my mind complex interactions between nature and nurture takes place.

    5. Excellent point to include.

    Overall mental disorders/illnesses do tend to be maladaptive, especially when experienced long term, however there are positives to them. The behaviours exhibited during depression/anxiety are a clue that something is not right for that individual (sounds more obvious than it is) and if listened to can help develop that individual’s sense of self towards who they actually want to be. Also there is the issue of creativity and the positive of that in bipolar disorder and schizophrenia. A lot of creativity can also come out of depression and I believe creativity can be a way of helping individuals through creative therapy. Expression of what is inside is healthy, but is often held back for many reasons and this can led to depression /anxiety. My experience is limited to depression/anxiety so how this classification impacts on other disorders I am unable to say, but it does need to be written in such a way as to be clear, helpful and also to include the positives. To concentrate on the negative can bring in stigma, which itself can increase the issues faced by the individual being classified.

  2. The requirement for "clinically significant distress or impairment" was removed from the criteria for Tic Disorders (eg Tourette's) in the DSM-IV-TR.

    The provided reasons for this change include that the requirement "is at variance with clinical experience" and "hinders epidemiological research and family studies."

  3. I believe many brilliant leaders deal with mental illness. I’d like to encourage you to also check out my book. It's titled, The Golden Flame: The Heart and Soul of Remarkable Leadership. You can find it at the following url: or purchase it at or your local bookstore.

  4. Anonymous2:13 pm

    I disagree that every mental disorder is the result of psychobiological dysfuncion; that is a very reductionist view, looking at mental illness only from a medical/psychiatric point of view. I think other factors come into play, and predisposition to mental illness can be both biological or psychological, not merely neural dysfunction.

  5. Anonymous1:18 am

    The DSM is published by the American Psychiatric Association, not the American Psychological Association as the article states. Even Wikipedia has this fact correct!

  6. On 3, I don't think the only "murkiness" is the boundary between normal and pathological responses but also, what constitutes a "common stressor"? What is "an expectable response" to, say, a young person getting out of an abusive home and finding the world very different? Or to being abducted, assaulted, and held against one's will? Is there any "expectable response" to such traumatic events that is less than mental illness or do experiences such as those constitute something outside of "common stressors" and, as such, automatically qualify one as mentally ill no matter the response? On another note, has psychology/psychiatry any recognition of responses to chronic illness? Perhaps uncommon stressors need recognition, too.
    (The first, I suppose I just needed some security and to know that it was the home that was bad rather than me and that things could be ok -- in addition to having some concepts rightly defined. Instead, I was told I was sick, that it was my mind, and that I shouldn't blame anyone else, certainly not my parents. The second, I very simply wasn't believed and was told my captor only wanted what was best for me. It was, shall we say, harmful.)

    I do agree that "disorders are more than mere 'labels'," but I also think how the labels are applied leaves much to be desired.

  7. Anonymous at 1.18AM - thanks for spotting that error which has now been corrected (I'm so used to typing American Psychological Association, I did it without thinking).

  8. I think the free ride that group behavior gets is sometimes unwarranted. For example, if you independentally feel compelled to bully gays, Muslims and many others who fail to meet your standards you're considered mentally ill if not outright criminal.

    Yet if you are equally abusive due to belonging to a group of conservative Christians you're considered just fine (apologies to individuals living in civilized nations where this is not the case - I live in the U.S. where religious bigotry is supported by our government). Meanwhile the people being bullied are just as abused either way.

  9. @ Anonymous said...
    *I disagree that every mental disorder is the result of psychobiological dysfuncion; that is a very reductionist view, looking at mental illness only from a medical/psychiatric point of view. I think other factors come into play, and predisposition to mental illness can be both biological or psychological, not merely neural dysfunction.*

    Does not a predisposition imply a biological underpinning?

  10. Anonymous2:14 pm

    Biological underpinning is really nonsensical for most things, in almost all biological issues be they mental/physical its falls under the biopsychosocial model. We don't develop in a vacuum.

    Some of what passes as logic is nonsensical. You could say we all have a biological basis for being fat, we just have to eat enough and burn few enough calories to have our cells adapt. Radical biological reductionists often assume causation without environmental stimuli, which does not stack up with the facts of human development be it psychological or more overtly physical.

    We are biological creatures that function both socially and have individual psychologies. They whole notion that something has a biological underpinning is just commonsensical, how can anything not relate to biology. But the key difference is attributing mental illness as primarily caused by some biological flaw, that somehow has not been influenced by thoughts, environment. We don't grow in test-tubes and environmental stimuli is the key determinant of neurological growth and pruning. Proteins turn on and off dependent upon stimuli for example.

    I don't understand why all mental health professionals can't get behind the idea that its not nature vs. nurture---its both a complex interplay. Sometimes individual biology may contribute significantly to how mental illness progress, although perhaps chronic abuse/neglect was the mover that basically trained that individuals brain to become good at depressing, anxiety, or even splitting etc.

    In other fields MD's promote Occupational therapy, physical re-hab, but some Psychiatrists/PFP act ignorantly to assume talk-therapy is somehow useless, when data shows quite the contrary. Also some talk-therapists refuse to see that some clients MUST have a calmer mental state and less neuronal activation to be able to process and engage in talk-therapy effectively. This is a useless debate that continues on in my opionion, it just shows the disconnect in the mental health system--that is for the most party not systematic and has become the Tower of Babel.

  11. I'm looking at this and wondering at what point this distinguishes mental illness from disorders such as Down's syndrome where the person is "different" from birth. In most cases of what used to be called mental handicap, I would have thought there would be distresses throughout life as a result of such differences, but it would be most unkind to group such a person with people who are mentally ill.

  12. Anonymous12:07 pm

    utterly stupid article,there are many different kinds of disorders,some of which have nothing to do with biological cannot have in the same pot developmental disorders with anxiety disorders and addiction with multiple personality and so on so forth.drug companies need their money don't they?if something is biological,then labs can cure it...utter nonsense,that's what I say.

  13. Anonymous1:56 pm

    pardon me,the article is just a report of the studies.I did not mean to insult the writer of the article but the ideas reproduced from the studies.cheers

  14. Anonymous3:18 pm