Critical thinking paper

World Psychiatry 9:1 - February 201056

In the last 50 years, personality disorder has achieved a level of understanding and, indeed, respectability that now allows it to be considered as an equal partner with other mental disorders. Before the 1960s, personality disorder, with the possible exception of the antisocial group, was con- sidered an unreliable and imprecise diagnosis with little or no clinical value. Since then, however, and particularly since the introduction of DSM-III in 1980, there has been increas- ing recognition that personality disorder, despite many im- perfections in its classification, can be described and rated reliably. Personality disorder has been shown to have an im- portant influence on the outcome of other mental disorders when present as a comorbid condition, and it may benefit from specific treatment. This article discusses these findings from a global perspective, as this has particular relevance to low-income countries in which personality disorder has un- til recently been seldom studied.

Personality disorder: a new global perspective

WPA SECTION REPORT

Peter tyrer1,2, roger Mulder1,3, Mike Crawford1,2, giles NewtoN-Howes4, erik siMoNseN1,5, david Ndetei6, Nestor koldobsky7, aNdrea fossati8, JosePH Mbatia9, barbara barrett10

1WPA Section on Personality Disorders; 2Department of Psychological Medicine, Imperial College, London; 3Department of Psychological Medicine, University of Otago, Christchurch, New Zealand; 4Hawkes Bay District Health Board, New Zealand; 5Institute of Personality Theory and Psychopathology (IPTP), Roskilde, Denmark; 6University of Nairobi, Kenya; 7National University, La Plata, Argentina; 8San Raffaele Hospital, Milan, Italy; 9Ministry of Health, Dar es Salaam, Tanzania; 10Centre for Economics of Mental Health, London

Personality disorder is now being accepted as an important condition in mainstream psychiatry across the world. Although it often re- mains unrecognized in ordinary practice, research studies have shown it is common, creates considerable morbidity, is associated with high costs to services and to society, and interferes, usually negatively, with progress in the treatment of other mental disorders. We now have evidence that personality disorder, as currently classified, affects around 6% of the world population, and the differences between countries show no consistent variation. We are also getting increasing evidence that some treatments, mainly psychological, are of value in this group of disorders. What is now needed is a new classification that is of greater value to clinicians, and the WPA Section on Per- sonality Disorders is currently undertaking this task.

Key words: Personality disorder, classification, treatment, comorbidity, epidemiology

(World Psychiatry 2010;9:56-60)

EPidEmiology

Although national morbidity studies of mental illness have now become more frequent in developed countries, they do not often record personality disorder. One of the main reasons for this is the difficulty in conducting assess- ments of personality disorder, especially with lay interview- ers. As a consequence, there are only a handful of such stud- ies of the literature (1-3). However, with the increasing use of short screening assessments for personality disorder (4,5), it is possible to conduct such assessments with lay interview- ers and provide valuable data.

Three major studies of the epidemiology of personality disorder have now been published in the last five years. The results are summarized in Table 1. By far the largest of these studies was conducted across 10 different countries, includ- ing six low- or middle-income countries. This study is par-

Table 1 Study methods and prevalence of personality disorder from recently published epidemiological studies

Author, year (ref.) Country Method Prevalence (%) Screening instrument

Huang et al, 2009 (6) Western Europe (WE), Colombia (C), Lebanon (L), Mexico (M), Nigeria (N), People’s Republic of China (PRC), South Africa (SA), United States (US)

Household surveys Multiple imputation used to predict personality disorder scores using a three part simulation procedure. Rates of personality disorder calculated as means of multiple imputation prevalence estimates (n=21,162)

WE: 2.4 C: 7.9 L: 6.2 M: 6.1 N: 2.7 PRC: 4.1 SA: 6.8 US: 7.6

33-item screening questions from the International Personality Disorder Examination (IPDE)

Coid et al, 2006 (3) England, Wales, Scotland Survey of a stratified sample of 15,000 households (n=628)

4.4 Screening questionnaire of SCID–II

Grant et al, 2004 (7) United States of America Random sample (National Epidemiologic Survey on Alcohol and Related Conditions) (n=43,093)

14.8 Alcohol Use Disorder and Associated Disabilities Interview Schedule, DSM- IV Version

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ticularly significant because it demonstrates that personality disorders are no less prevalent outside Europe, North Amer- ica and Australia, where all previous data have been col- lected. The study is also important because it shows that problems in social functioning among people with personal- ity disorder are clinically significant, even when the impact of other comorbid mental health problems has been con- trolled for (6).

How comorbid PErsonality disordEr influEncEs otHEr mEntal disordErs

As the identification of personality pathology has become increasingly robust, it has become possible to turn our atten- tion to how this group of disorders affect other mental dis- orders, such as affective and psychotic disorders, more com- monly identified and treated within mental health settings. Although the community prevalence of personality disorder appears to range from 3 to 10%, it is, as would be expected, much higher in secondary care settings (8,9). As such, it would be expected to impact on psychopathology, outcome and service provision. The research undertaken to date, al- though limited in a similar fashion to the epidemiological data, would broadly support this view.

The best studied association is between depressive disor- ders and personality status. More than 60 studies have looked at the correlation between personality disorder and depression and, when combined using a meta-analytic ap- proach, they confirm that people with a personality disorder are approximately twice as likely not to recover from a de- pressive episode as those with no personality disorder (un- published data). This data is very similar to initial findings of poorer outcome in depression when personality pathol- ogy is present (10). Studies do not make it clear whether this poorer outcome is due to the lack of treatments directed at the personality pathology or if personality disorder acts as a diathesis in these conditions (11).

The findings in psychotic mental illness are far less clear. This field of research is less well developed and even the prevalence of personality pathology ranges from 4.5 to 100%. This huge variation appears to be related to the coun- try of the study, the care provided and the tools used to mea- sure personality (12). It is not clear that personality mea- sures in psychosis are reliable (13). Outcomes in this group are also poorly studied (14), although there are peripheral indicators that personality disorder in this group often shows itself in terms of violence (15), crime (16), and hospital re- admission (17).

Other research has examined the interactions of personal- ity pathology and major mental illness within community and secondary care settings. This also supports the probabil- ity of poorer outcomes in personality disordered patients who are, by and large, treated for affective and psychotic disorders. Two-year outcomes in an Australian cohort showed the personality facet of neuroticism to be one of the

few correlates predictive of poor outcome in those with men- tal illnesses (18). Cross-sectional data has also suggested per- sonality disorder, particularly its severity, to be associated with both higher social needs and greater social dysfunction in patients in a secondary care setting in England (19).

Studies such as these suggest that personality dysfunction has a negative effect on function and outcome, but remains relatively undertreated. Why is this? The answer to this question is potentially multifaceted, although clinicians’ at- titudes toward this difficult to manage group are important. For more than two decades, there has been the suggestion that mental health clinicians do not like patients with per- sonality disorders (20), and recent evidence suggests that clinicians perceive patients with personality disorders as more difficult, despite the objective evidence failing to sup- port such a view (21). These attitudes may adversely affect delivery of health care provision and as such make it more difficult for patients with personality disorder and comorbid mental disorders to access and receive appropriate manage- ment for either disorder.

It therefore appears that people with personality disorder and comorbid personality disorder have poorer outcomes, function less well in society and are stigmatized by clinicians in secondary services, reducing the odds they will receive optimum care. This is a combination which is potentially expensive when considering the delivery of health and so- cial care services.

cost of PErsonality disordEr

As part of a recent report on the economic burden of mental health problems in England, the King’s Fund esti- mated the health and social care service costs of all people with personality disorder who are in contact with their gen- eral practitioners at £704 million per year (22). When pro- ductivity losses were included, the cost rose to £7.9 billion per year. Soeteman et al (23) used a similar approach to calculate the cost of personality disorder by using data from health and social care contacts for people attending special- ist personality disorder services. They calculated the total burden of personality disorder in the Netherlands to be £11,126 per patient.

These studies can be considered a useful starting point, but they do not provide an estimate of the total economic burden of personality disorder, because both of them used information on people who were in contact with services. Whilst service attenders provide useful opportunistic sam- ples for research purposes, they are not representative of the personality disorder population as a whole. Indeed, we know that many of those with personality disorder are un- known to services (24), reject treatment rather than seek it (25), or are in contact with services but have a different pri- mary diagnosis (26). Thus, to date, the true cost of personal- ity disorder remains unknown, but it is certainly substantial, falling to many service providing sectors (health, social ser-

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vices, criminal justice) as well as to the economy more wide- ly (inability to work and premature death).

EvidEncE of trEatmEnt EffEctivEnEss

Most of the research conducted into the treatment of per- sonality disorder has focused on those with borderline per- sonality disorder. Systematic reviews of previously published randomized trials have concluded that too few studies have been conducted to draw clear conclusions about the treat- ment of this form of personality disorder, but they have high- lighted the limited, if any, impact of pharmacological treat- ments and the promising, if still unclear, benefits of complex psychosocial interventions such as dialectical behaviour therapy (27,28).

The treatment of people with borderline personality dis- order has also been reviewed as part of the development of national guidelines. Following the publication of the Amer- ican Psychiatric Association’s guidelines in 2001 (29), the National Institute for Clinical Excellence in England (NICE) published new treatment guidelines for borderline and anti- social personality disorder (30,31). The evidence base led to three main conclusions: a) psychotropic drugs are of no proven value in the long term in these personality disorders, and their adverse effects normally preclude their use except for short periods and in crisis; b) if other treatments (mainly psychological) are to be given, they need to be administered using a structured team approach for borderline personality disorder and using cognitive therapeutic approaches (par- ticularly group management) in antisocial personality disor- der; c) in antisocial personality disorder, interventions that reward are better than those that punish.

Information on which to base treatment discussions for people with other forms of personality disorder is even more scant. Recent trials by Svartberg et al (32) and Emmelkamp et al (33) are noteworthy because they examined the impact of psychological treatments among people with cluster C personality disorders. Findings from these two trials dis- agree, with Emmelkamp et al demonstrating greater im- provement among those offered 20 sessions of cognitive therapy compared to psychodynamic psychotherapy, while Svartberg et al found similar treatment outcomes among those receiving these two interventions.

For other forms of personality disorder in which the pa- tients are treatment resisting (Type R) (i.e., they do not want their personalities to change), as opposed to treatment seek- ing (Type S) (25), it may be better to try and adapt the envi- ronment to the personality and this can be done systemati- cally in the form of nidotherapy (34,35). This has received support in a recent randomized trial (36).

Most of the putative successful treatments for personality disorder are time consuming and resource intensive, and need to be buttressed by a good theoretical base and thera- peutic commitment. These conclusions match those of an expert panel on the management of people with personality

disorder (37), which also suggested that there is no “quick fix” in the treatment of these disorders, and that in most countries the resources are not likely to be available to treat them in this way.

While research for treatment of personality disorder that goes beyond the previous focus on borderline personality disorder is to be welcomed, findings from other studies show that in clinical practice people offered treatment usually meet diagnostic criteria for several categories of personality disorders (38,39). Such findings add weight to the case for re-classifying personality disorder to ensure that the system used has clinical utility.

nEEd for a nEw classification

If we accept the epidemiological figures, 3-10% of the adult inhabitants in the countries of the world have a per- sonality disorder. However, only a minority of these (prob- ably one in 20) has a severe personality disorder (40) and it is the people in this group who cause the most disruption to services and to society.

For the most severe personality disorders, the existing classification is unhelpful. It takes no account of severity and it generates the frequent comorbidity of several person- ality disorders across different clusters (41), as well as the frequent use of the term “personality disorder not otherwise specified”, which, when often used more than any specific personality category, is a mark of dissatisfaction with the existing classification (42).

The WPA Section on Personality Disorders is currently examining new ways of classifying personality disorder in ICD-11. As well as making suggestions over the classifica- tion of severity discussed above, the Section is considering revising the descriptions of the major personality disorder groupings. These would be fewer, overlap less and, we hope, possess greater clinical utility.

There is surprising consistency over the number and de- scriptions of the main dimensions of personality disorder in studies carried out with both psychiatric patients and nor- mal populations. Three or four dimensions are uniformly reported (43-46), in addition to the well-known five-factor model (47) that has been suggested for the core descriptions of DSM-V personality disorders (48).

The first dimension is an externalizing potentially aggres- sive and hostile factor that incorporates borderline, antiso- cial, narcissistic, histrionic (cluster B in DSM-IV) and often paranoid personality disorder traits. Some studies report a separation of a factor incorporating callousness, lack of re- morse and criminal behaviour (psychopathy), while others find a single broad factor. The second dimension is gener- ally an internalizing factor consisting of neurotic, inhibited and avoidant, incorporating anxious, behaviour. This was once called asthenia, but is now best summarized as avoidant and dependent personality disorder traits (part of cluster C) in DSM-IV. The third dimension comprises schizoid symp-

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toms: introversion and social indifference, aloofness and restricted expression of affect. In some studies these charac- teristics overlap with eccentric and odd behaviour and/or paranoid personality disorder symptoms, and an additional factor, peculiarity, has been suggested to make up a six-fac- tor model (49). The fourth factor comprises obsessionality, compulsivity and perfectionism and, although these are cur- rently part of the cluster C grouping, the empirical data sug- gests they can be separated. In some studies this forms part of the internalizing factor, but most investigations report that obsessive compulsive personality disorder symptoms split off as a coherent and relatively independent set of be- haviours.

While there is currently little evidence to support the va- lidity of these factors, they almost certainly provide a better description of the range of personality abnormality than the current classifications. They can also be adapted to a devel- opmental perspective that will allow personality disturbance to be identified long before the current cut-off age of 18 that is intrinsic to both DSM-IV and ICD-10 (50). Their impor- tance will rest on whether they provide a more useful frame- work for organizing and explaining the complexity of clini- cal experience in personality disorders as well as predicting outcome and guiding decisions about treatment (51). A new classification that does not improve clinical utility will be a failed classification.

There seems little to lose. A recent survey reported that three quarters of personality disorder experts thought the current DSM-IV system should be replaced (42). Using four (or possibly more) overlapping factors seems preferable to continuing to act as though the ten current personality dis- orders are separate, when they have repeatedly been found not to be.

The next step will be to derive better structured clinical interviews that address these factors well, and this should generate competent research which can explore whether knowledge about aetiology, prognosis and treatment is en- hanced by using the new classification.

The DSM-IV polythetic diagnoses describe poorly speci- fied psychopathology and so it is natural that they fail to identify criteria that could correspond to the “core features” of each personality disorder diagnosis. The lack of clearly identified core features and a “vote-counting” approach to personality disorder diagnosis (i.e., list the number of symp- toms that were met by a given subject, see if it is greater than a usually arbitrary cut-off value, and then make the diagno- sis) prevented clinicians from making differential diagnoses within the axis II classification. The legacy is a diagnostic system that dissatisfies both the researcher and the clinician, being neither simple, accurate or useful. Thus, although it has promoted a huge, but widely scattered, amount of re- search on the aetiology, psychopathology, course and treat- ment of personality disorders, there are now good reasons to consider the DSM-IV approach completely out of date.

The WPA Section on Personality Disorders is currently considering revising the descriptions of the major personal-

ity disorder groupings in a way that not only makes good clinical sense but also enables separation from other disor- ders with which they are frequently confused, such as atten- tion-deficit/hyperactivity disorder (ADHD) (52). It will not be an easy task, and in reaching our conclusions we hope to have empirical evidence from as many field trials as possible, not just in highly developed countries, as a robust classifica- tion should travel well (53), and to use these data rather than relying on the uncertain support of consensus committee opinion, as previous classifications have unfortunately been forced to do.

references

Torgersen 1. S, Kringlen E, Cramer V. The prevalence of personality disorders in a community sample. Arch Gen Psychiatry 2001; 58:590-6. Cohen BJ, Nestadt G, Samuels JF et al. Personality disorder in later 2. life: a community study. Br J Psychiatry 1994;165:493-9. Coid J, Yang M, Tyrer P et al. Prevalence and correlates of personal-3. ity disorder among adults aged 16 to 74 in Great Britain. Br J Psy- chiatry 2006;188:423-31. Langbehn DR, Pfohl BM, Reynolds S et al. The Iowa personality 4. disorder screen: development and preliminary validation of a brief screening interview. J Person Dis 1999;13:75-89. Moran P, Leese M, Lee T et al. Standardised Assessment of Person-5. ality - Abbreviated Scale (SAPAS): preliminary validation of a brief screen for personality disorder. Br J Psychiatry 2003;183:228-32. Huang Y, Kotov R, de Girolamo G et al. DSM-IV personality disor-6. ders in the WHO World Mental Health Surveys. Br J Psychiatry 2009;195:46-53. Grant BF, Hasin DS, Stinson FS et al. Prevalence, correlates, and 7. disability of personality disorders in the United States: results from the national epidemiologic survey on alcohol and related condi- tions. J Clin Psychiatry 2004;65:948-58. Newton-Howes G, Tyrer P, Anagnostakis K et al. The prevalence of 8. personality disorder, its comorbidity with mental state disorders, and its clinical significance in community mental health teams. Soc Psychiatry Psychiatr Epidemiol (in press). Cutting J, Cowen PJ, Mann AH et al. Personality and psychosis: use 9. of the Standardised Assessment of Personality. Acta Psychiatr Scand 1986;73:87-92. Newton-Howes G, Tyrer P, Johnson T. Personality disorder and the 10. outcome of depression: a meta-analysis of published studies. Br J Psychiatry 2006;188:13-20. Tyrer P. Personality diatheses: a superior explanation than disorder. 11. Psychol Med 2007;37:1521-5. Newton-Howes G, Tyrer P, Yang M et al. The prevalence of person-12. ality disorder in schizophrenia: rates and explanatory modelling. Psychol Med 2008;37:1-8. Docherty J, Fiester S, Shea T. Syndrome diagnosis and personality 13. disorders. In: Frances AJ, Hales RE (eds). American Psychiatric Association annual review, Vol. 5. New York: American Psychiatric Press, 1986:315-55. Newton-Howes G, Tyrer P, Moore A et al. Personality disorder and 14. outcome in schizophrenia: a negative systematic review. Person Ment Health 2007;1:22-6. Moran P, Walsh E, Tyrer P et al. Impact of co-morbid personality 15. disorder on violence in psychosis – report from the UK700 trial. Br J Psychiatry 2003;182:129-34. Moran P, Hodgins S. The correlation of comorbid antisocial per-16. sonality disorder in schizophrenia. Schizophr Bull 2004;30:791- 801.

056-060.indd 59 26-01-2010 15:59:01

World Psychiatry 9:1 - February 201060

Tyrer P, Manley C, VanHorn E et al. Personality abnormality and its 17. influence on outcome of intensive and standard case management: a randomised controlled trial. Eur Psychiatry 2000;15(Suppl 1):7- 10. Beard J, Heathcote K, Brooks R et al. Predictors of mental disorders 18. and their outcomes in a community based cohort, Soc Psychiatry Psychiatr Epidemiol 2007;42:623-30. Newton-Howes G, Tyrer P, Weaver T. Social function of patients 19. with personality disorder in secondary care. Psychiatr Serv 2008; 59:1033-7. Lewis G, Appleby L. Personality disorder: the patients psychiatrists 20. dislike. Br J Psychiatry 1988;153:44-9. Newton-Howes G, Weaver T, Tyrer P. Attitudes of staff towards 21. patients with personality disorder in community health teams. Aust N Z J Psychiatry 2008;42:572-7. McCrone P, Dhanasiri S, Patel A et al. Paying the price: the cost of 22. mental health care in England to 2026. London: King’s Fund, 2008. Soeteman DI, Hakkaart-van Roijen L, Verheul R et al. The eco-23. nomic burden of personality disorders in mental health care. J Clin Psychiatry 2008;69:259-65. National Institute of Mental Health in England. Personality disor-24. der: no longer a diagnosis of exclusion. Leeds: National Institute of Mental Health in England, 2003. Tyrer P, Mitchard S, Methuen C et al. Treatment-rejecting and treat-25. ment-seeking personality disorders: Type R and Type S. J Person Disord 2003;17:265-70. Ranger M, Methuen C, Rutter D et al. Prevalence of personality 26. disorder in the caseload of an inner city assertive outreach team. Psychiatr Bull 2004;28:441-3. Binks CA, Fenton M, McCarthy L et al. Psychological therapies for 27. people with borderline personality disorder. Cochrane Database of Systematic Reviews, Issue 1, 2005. Binks C, Fenton M, McCarthy L et al. Pharmacological interven-28. tions for people with borderline personality disorder. Cochrane Database of Systematic Reviews, Issue 1, 2006. American Psychiatric Association. Practice guideline for the treat-29. ment of patients with borderline personality disorder. Am J Psy- chiatry 2001;158(Suppl.). National Institute of Health and Clinical Excellence. Borderline 30. personality disorder: treatment and management. London: Nation- al Institute of Health and Clinical Excellence, 2009. National Institute of Health and Clinical Excellence. Antisocial 31. personality disorder: treatment, management and prevention. Lon- don: National Institute of Health and Clinical Excellence, 2009. Svartberg M, Stiles TC, Seltzer MH. Randomized, controlled trial 32. of the effectiveness of short-term dynamic psychotherapy and cog- nitive therapy for cluster C personality disorders. Am J Psychiatry 2004;161:810-7. Emmelkamp PM, Benner A, Kuipers A et al. Comparison of brief 33. dynamic and cognitive-behavioural therapies in avoidant personal- ity disorder. Br J Psychiatry 2006;189:60-4. Tyrer P, Sensky T, Mitchard S. The principles of nidotherapy in the 34. treatment of persistent mental and personality disorders. Psychoth- er Psychosom 2003;72:350-6.

Tyrer P, Kramo K. Nidotherapy in practice. J Ment Health 2007; 35. 16:117-31. Ranger M, Tyrer P, Milošeska K et al. Cost-effectiveness of nido-36. therapy for comorbid personality disorder and severe mental ill- ness: randomized controlled trial. Epidemiol Psichiatria Soc 2009; 18:128-36. Crawford MJ, Price K, Rutter D et al. Dedicated community-based 37. services for adults with personality disorder: Delphi study. Br J Psy- chiatry 2008;193:342-3. Giesen-Bloo J, van Dyck R, Spinhoven P et al. Outpatient psycho-38. therapy for borderline personality disorder: randomized trial of schema-focused therapy vs. transference-focused psychotherapy. Arch Gen Psychiatry 2006;63:649-58. Abbass A, Sheldon A, Gyra J et al. Intensive short-term dynamic 39. psychotherapy for DSM-IV personality disorders: a randomized controlled trial. J Nerv Ment Dis 2008;196:211-6. Tyrer P. Personality disorder and public mental health. Clin Med 40. 2008;8:423-7. Bowden Jones O, Iqbal MZ, Tyrer P et al. Prevalence of personality 41. disorder in alcohol and drug services and associated co-morbidity. Addiction 2004;99:1306-14. Bernstein DP, Iscan C, Maser J et al. Opinions of personality disor-42. der experts regarding the DSM-IV personality disorders classifica- tion system. J Person Disord 2007;21:536-51. Tyrer P, Alexander J. Classification of personality disorder. Br J Psy-43. chiatry 1979;135:163-7. Livesley WJ. A systematic approach to the delineation of personal-44. ity disorders. Am J Psychiatry 1987;144:772-7. Mulder RT, Joyce PR. Temperament and the structure of personal-45. ity disorder symptoms. Psychol Med 1997;27:99-106. Fossati A, Maffei C, Bagnato M et al. Patterns of covariation of 46. DSM-IV personality disorders in a mixed psychiatric sample. Com- pr Psychiatry 2000;41:206-15. Costa PT, McCrae RR. Personality disorders and the five-factor 47. model of personality. J Person Disord 1990;4:362-71. Widiger TA, Mullins-Sweatt SN. Five-factor model of personality 48. disorder: a proposal for DSM-V. Ann Rev Clin Psychol 2009;5:197- 220. Watson D, Clark LA, Chmielewski M. Structures of personality and 49. their relevance to psychopathology: II. Further articulation of a comprehensive unified trait structure. J Person 2008;76:1545-86. Tackett JL, Balsis S, Oltmanns TF et al. A unifying perspective on 50. personality pathology across the life span: developmental consider- ations for the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders. Dev Psychopathol 2009;21:687-713. Kendell R, Jablensky A. Distinguishing between the validity and 51. utility of psychiatric diagnoses. Am J Psychiatry 2003;160:4-12. Philipsen A, Limberger MF, Lieb K et al. Attention-deficit hyperac-52. tivity disorder as a potentially aggravating factor in borderline per- sonality disorder. Br J Psychiatry 2008;192:118-23. Thuo J, Ndetei DM, Maru H et al. The prevalence of personality 53. disorders in a Kenyan inpatient sample. J Person Disord 2008;22: 217-20.

056-060.indd 60 26-01-2010 15:59:01