Categories and clusters

The first thing to say about the diagnosis of personality disorder is that the vast majority of people 'with PD' are not in the least like the stereotypes of sociopaths so readily bandied about in the media. Here, PD - 'psychopaths - are regularly used either as a modern day 'folk devil', or as a sensationalist device, or simply a way to cover up a weakness in a plot.

The second thing is that the diagnosis of personality disorder is contentious - even as psychiatric diagnoses go. The sociologist Nick Manning, for example, suggested that the diagnosis of personality disorder only came about in a post-industrial era, when social skills had become central to social success; and it seems to disappear in war zones. 

But if for the moment we can accept that there must be at least some kind of validity in these measures of human distress, then the epidemiological studies alone would suggest that there is a major community mental health problem, and a huge level of distress and dysfunction that the homelessness services in western economies may be dealing with. 

Using - if only for want of an alternative - one of the accepted diagnostic classification systems for mental disorders, the levels of each of the principal forms of personality disorder  in the population as a whole are striking. A meta-analysis*  identifies levels of PD in the community, finding that at 10-15% of the population have at least one PD, at or beyond the threshold of diagnosis.   This contrasts with the 'official' statistics for levels of personality disorder identified as such by the UK Department of Health, for example. 

If it is the case that - even on the lower estimate - 10% of the population have a personality disorder, we would expect to find a greater concentration is those areas of life that people with problematic behaviour and relationships will tend to gravitate towards. The statistics indicate far higher concentrations in in-patient services. We would expect a higher concentration in criminal justice and the prison service - though this may not in fact be the anti-social personality disorder, as is often assumed. 

The analysis identifies numbers by PD 'type": though it is not necessary at this stage to define each type in detail.   For the paranoid type, collective assessments suggest 1.1% of the population as a whole. For the schizoid type, 0.6; for the schizotypal, 1.8%; the 'histrionic', 2.0; the anti-social, 1.2%; the 'narcissistic' - surprisingly? - too low to calculate.The 'avoidant type, 1.2%; the 'dependent', 2.2%; the passive aggressive, 2.1% and finally the obsessive, the largest group of all at 4.3%. 

*PD symptomatology - a longitudinal perspective, Sansome R and Sansome L. in  New research on personality disorders, Eds  Halvorsen, Ida V; Olsen, Sarah N


The history of a diagnosis

Clinical classification methods have struggled to identify the principal characteristics, let alone the underlying dynamics or causes;  and formal diagnosis - the 'medical model' - has fared no better. 

Attempts to pin down the nature of mental disorders, either to assess the level of need for such services, or the eligibility and suitability of individuals for these services, go back to the early 19th Century, and the first development of large hospitals for the insane. Census approaches gradually gave way to attempts to identify patterns of service use, and diagnoses based as much on frequency/chronicity as on other actual characteristics, let alone the internal world of the patient as seen by the patient themselves. 

The American 'Diagnostic and Statistical Manual, now on its 5th edition, aims to provide a common language and standard criteria for thee classification of mental disorders. The various editions allow us to track to attempts to locate problematic personalities within what is essentially a medical model, in which there are distinct and consistently identifiable illnesses, with specific common characteristics.

In the first edition of the Manual (aka DSM I ) published in 1952, there is no category of personality disorder. The second edition - DSM II - introduces the suggestion that PD, rather than being a separate category of problems along side all others, can be seen as an extra dimension, or axis. Personality disorders were referred to as 'Axis II disorders'; and it was assessed that 85% of patients with an Axis II personality disorder had at least one other diagnosis.  

DSM III, appearing in 1968, reflected a decade in which the entire worldview of psychiatry had been challenged, both by internal critics, and by sociologists and psychologists, questioning how the concept of 'illness' was applied to 'problems in living'. DSM IV, in 1994, proposed a multi-axial approach, seeing personality as one of a number of possible 'axes' that contributed to the status of any particular behaviour as problematic 

Paranoid PD:            1.1%

Scizoid PD:               0.6%

Schizotypal PD:       1.8%

Histrionic PD:              2.0%

Antisocial PD:              1.2%

Avoidant PD:                 1.2%

Dependent PD:              2.2%

Passive Aggressive PD: 2.1%

Obsessive PD                4.3%

Further reading