Another way of classifying mental illness is to use a rather older classification which rates the disorder roughly in terms of the degree of control and insight the person has into their condition and its amenability to treatment. This breaks down mental and neurological conditions into four types.

Organic (neurological) disorders

Organic disorders are those in which there is a clear and physically testable pathological process going on in the brain. Examples include Alzheimer’s disease, Parkinson’s disease, Tourette’s syndrome, epilepsy, stroke-associated brain injury, delirium and certain AIDS-defining illnesses such as toxoplasmosis and PML, not to mention HIV-associated dementia (see below). Depending on the part of the brain affected, the person may be quite ‘sane’ with their cognitive functions unaffected, as in Parkinson’s disease, or may suffer complete loss of personality, as in Alzheimer’s.

Certain conditions such as autism and schizophrenia used to be thought of as psychological in origin, but are now as likely to be seen as organic brain disorders (often made worse by the psychological and social impact of the illness).

Autism, for instance, may be related to a greater or lesser disturbance in development of a group of brain cells called ‘mirror neurones’. In experiments on monkey, these were observed to fire when, and only when, another monkey was observed to do something. These neurones mirror the activity of a group of cells called ‘canonical neurones’ that fire when the person performs the task themselves. What this leads to is a condition in which the person, in a very profound way, lacks empathy. They do not have a ‘theory of mind’, which means an instinctive understanding that other people have minds similar to their own and may be presumed to be having the same thoughts and feelings when they do similar things. To an autistic person, therefore, all people are, to a greater or lesser degree, objects, and objects are not classified into things with more or less personal significance. This leads to symptoms such as fixations typical of autism, in which the person may obsess on particular repetitive activities in order to make sense of what is otherwise a meaningless (and painful) flux of experience (see Grèzes).

In the case of schizophrenia, research is still seeking a definitive cause. But what appears to happen is that genetic defects lead to a situation in which the neurotransmitters (messenger chemicals) dopamine and glutamate are synthesised in the wrong amounts – too much or too little – in different parts of the brain. Since neurotransmitters actually change brain architecture by creating and destroying synapses (the connections or ‘routing switches’ between cells), the result is a state in which the brain is wired up wrongly. Antipsychotic drugs effect a partial cure by changing dopamine levels in the brain, though in a global and unsubtle way (see Owen).

Psychoses

Psychoses are psychological disorders which are typical of what the lay person thinks of as ‘madness’. The key characteristic is that the person has lost insight – they are no longer aware that their mind is functioning abnormally and will attribute symptoms and feelings to influences outside themselves or not think anything is wrong at all. In other words, they are delusory. Florid (unmedicated or uncontrolled) schizophrenia is still seen as a psychosis, but mood disorders such as bipolar illness and major depressive disorder become psychotic in nature when delusions are present. A manic person may believe themselves to be a great ruler or prophet, for instance, while a depressive may become convinced they have committed some dreadful crime and actually hand themselves into the police. Delusory elements may be present in other conditions such as hypochondria or anorexia (where the person is convinced they are fat despite being skeletal). Not all situations in which insight is lost are psychoses: total organic disorder, as in delirium, is not psychotic. A psychosis is something in which there is some structure of thought and cognition, but one which feels ‘alien’ and is at variance with reality. To quote the saying: “neurotics build castles in the air: psychotics live in them.”

Neuroses

Neuroses form the overwhelming majority of mental ill-health. It is unfortunate that ‘neurotic’ has become a pejorative terms as it is still clinically useful.

A neurotic has not lost insight into their condition; on the contrary, they are only too aware, and sometimes exaggeratedly so, that there is something wrong with them. However they feel to a greater or lesser degree helpless to change this. They have not lost insight, but they have lost self-efficacy, a fundamental belief in their own mental balance and ability to deal with life.

In this there is hope, as people with neuroses are often highly motivated to change, though they may at the same time resist change.

Personality disorders

These form a category of mental illness or condition invented to cover the fact that there are a lot of people around who are not delusory, and do not generally feel that they are in an ‘abnormal’ state of mind, but whose lives seem to be shaped by significant defects in their ability to function socially. Personality disorder is something that is global – it is a way of being rather than a specific deficit or excess of some feeling or trait – and enduring, i.e. it is lifelong, or at least intractable to treatment.

Probably about 10% of the population has some degree of personality disorder, though this does not mean that they will all seek or need treatment.

DSM-IV defines personality disorder as “an enduring pattern of inner experience that deviates markedly from the expectations of the individual’s culture…which is inflexible and pervasive across a broad range of personal and social situations.” Essentially, people with personality disorders are misfits – and the causes are often thought to lie in inadequate parenting during childhood, or a ‘misfit’ between a child’s needs and what their parents (and extended family and peers) were able to provide them. It organises personality disorders into three broad categories. We will look at a few of them in more depth.

Cluster A are the paranoid, schizoid and schizotypal disorders. People with these disorders may seem suspicious, cold or eccentric to others. They will tend not to relate easily to others because they are genuinely not very interested in socialising or because they are distrustful of others. They may be litigious or have odd beliefs.

Cluster B are the antisocial, borderline, histrionic and narcissistic disorders. These people may appear overly emotional, selfish, self-absorbed, dependent on or manipulative towards others. They appear driven by odd but very strong and inflexible emotional needs.

• Antisocial personality disorder is also known as psychopathy or sociopathy. The person essentially acts as if they have no conscience or regard for the feelings of others. It is estimated that 3% of men and 1% of women have a degree of antisocial disorder.
• Narcissistic personality disorder may appear on the outside like anti-social disorder, but unlike true sociopaths, the narcissist is driven by strong feelings of low-self worth which he (75% are male) dare not show to others. The person is someone who constantly shows off, has to be the centre of attention, and has a need to be praised and flattered; they will often be quite high achievers if work serves their purposes, but their personal relationships will tend to be shallow and brief as they cannot bear criticism. About 1% of the population may have this disorder.
• Histrionic personality disorder is typified by the ‘drama queen’; the person depends on provoking strong emotional and usually sexual reactions in others (positive or negative). Traditionally more common in women, though this may be governed by social disapproval against sexually flamboyant women.
• Borderline personality disorder is typified by an alternately clinging and hostile style of relationship; the person desperately seeks love and approval but it is of such an all-or-nothing character that they inevitably become hostile and jealous. The Glenn Close character in ‘Fatal Attraction’ is often held up as an archetype of the borderline personality, though most people with this condition are more dangerous to themselves than others, as they are often prone to suicidality, self-harm and risk-taking behaviour, including substance and sexual addiction. The inner dilemma of the borderline person is that they feel empty or non-existent as a personality in their own right and are so both utterly dependent on others and yet hate that dependence. Borderline disorder is an increasingly common diagnosis, leading some psychologists to theorise about the role of weak family relationships and especially extended family in its cause. About 75% of those diagnosed are women, and there is a strong association with sexual or other abuse in childhood.

Cluster C are people whose lives seem governed by anxiety rather than suspicion (cluster A) or need (cluster B). They include obsessive-compulsive disorder, in which while not necessarily suffering from OCD to a disabling degree, the person is ruled by perfectionism and may be very ‘stiff’ and formal. People with avoidant personality disorder are governed by shyness and social inadequacy (as opposed to suspicion). Lastly, people with dependent personality disorder are afraid of being on their own and typically develop submissive or compliant behaviours in order to avoid displeasing people.

References - Introduction and definitions

Bolton P, Bass J, Neugebauer R, et al. Group interpersonal psychotherapy for depression in rural Uganda: a randomized controlled trial. JAMA 289: 3117-3124, 2003.

Browne G, Steiner M, Roberts J, et al. Sertraline and/or interpersonal psychotherapy for patients with dysthymic disorder in primary care: six month comparison with longitudinal two year follow-up of effectiveness and costs. J Affect Disord  68: 317-330, 2002.

Burnand Y, Andreoli A, Kolatte E, et al. Psychodynamic psychotherapy and clomipramine in the treatment of major depression. Psychiatr Serv 53: 585-590, 2002.

Cournos F.  Sexual activity and risk of HIV infection among patients with schizophrenia. Am J Psychiatry 151: 228-232, 1994.

Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). American Psychiatric Association, 2000. ISBN No. 0-89042-025-4.

European Men’s Health Forum. European HIV Quality of Life Review. Full Report, July 2005. Available from http://www.emhf.org/resource_images/HIVsurveyfinalresults.pdf

Gill D. Antidepressants for depression in medical illness. Cochrane Rev Abstract.  2005. See http://www.cochrane.org/reviews/en/pk111999091612245715.html

Grèzes J. Activations related to “mirror” and “canonical” neurons in the human brain: an fMRI study. NeuroImage 18: 928–937, 2003.

House JS. Social relationships and health. Science 241(4865): 540-545, 1988.

Martin JI. Loneliness and sexual risk behavior in gay men. Psychol Rep. 81(3 Pt 1): 815-825. 1997.

Miller P, Chilvers C, Dewey M, et al. Counseling versus antidepressant therapy for the treatment of mild to moderate depression in primary care: economic analysis. Int J Technol Assess Health Care 19: 80-90. 2003.

Owen MJ. Schizophrenia: a genetic disorder of the synapse? BMJ. 330(7484): 158-159, 2005.

Rogers G. Depressive disorders and unprotected casual anal sex among Australian homosexually active men in primary care. HIV Medicine 4: 271–275, 2003.

Scott J, Palmer S, Paykel E, et al. Use of cognitive therapy for relapse prevention in chronic depression. Cost-effectiveness study. Br J Psychiatry 182: 221-227, 2003