Table Of ContentPERSONALITY DISORDER IN PERPETRATORS OF
HOMICIDE
A thesis submitted to the University of Manchester for the degree of
Doctor of Philosophy
in the Faculty of Medical and Human Sciences
2013
DR NICOLA SWINSON
SCHOOL OF MEDICINE
Faculty of Medical and Human Sciences
Contents
List of tables ............................................................................................................................ 7
List of Figures ......................................................................................................................... 8
Abstract ................................................................................................................................... 9
Declaration ............................................................................................................................ 10
Copyright Statement ............................................................................................................. 11
Acknowledgements .............................................................................................................. 12
Dedication ............................................................................................................................. 13
The Author ............................................................................................................................ 14
Overview ............................................................................................................................... 15
Chapter 1 - Introduction ........................................................................................................ 17
1.1 Search strategy........................................................................................................... 17
1.2 Personality .................................................................................................................. 18
1.21 The conceptualisation of personality .................................................................... 18
1.22 Stability and continuity of personality ................................................................... 19
1.23 Personality and Violence ...................................................................................... 22
1.3 Personality Disorder ................................................................................................... 24
1.31 Current Classification of Personality Disorder ...................................................... 24
1.32 Classification of Antisocial Personality Disorder .................................................. 28
1.4 Development of Antisocial Personality Disorder ........................................................ 32
1.41 Pathways to antisocial behaviour ......................................................................... 32
1.42 Risk and Protective Factors .................................................................................. 37
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1.5 Personality Disorder and Violence ............................................................................. 50
1.51 Antisocial Personality Disorder and Violence ....................................................... 50
1.52 Other personality disorders and violence ............................................................. 53
1.53 Personality Disorder Clusters ............................................................................... 57
1.54 Psychopathy and Violence ................................................................................... 58
1.6 Personality Disorder and Homicide ............................................................................ 61
1.7 Medicolegal aspects ................................................................................................... 67
1.8 Summary of literature review ...................................................................................... 74
Chapter 2 - Background to the current study, Aims and Research Questions .................... 76
2.1 Background to the current study ................................................................................. 76
2.2 Aims ............................................................................................................................ 78
2.3 Research Questions ................................................................................................... 79
2.4 Ethical Considerations ................................................................................................ 79
Chapter 3 – Methodology ..................................................................................................... 80
3.1 Quantitative and qualitative methodologies ................................................................ 80
3.2 Mixed Methods ........................................................................................................... 82
3.3 Approaches to Mixed Methods Research .................................................................. 85
3.4 Rigour within the research process ............................................................................ 87
Chapter 4 - Quantitative study .............................................................................................. 89
4.1 Quantitative Methods .................................................................................................. 89
4.11 National Confidential Inquiry data collection ........................................................ 89
4.12 Measures .............................................................................................................. 90
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4.13 Sample .................................................................................................................. 92
4.14 Data analysis ........................................................................................................ 96
4.2 Quantitative Results ................................................................................................... 99
4.21 Prevalence of personality disorder in a national case series of perpetrators of
homicide ....................................................................................................................... 99
4.22 Correlations between domains & dimensions of personality disorder and
circumstances of the offence ...................................................................................... 104
4.23 Sociodemographic, Clinical and Criminological factors associated with a
diagnosis of personality disorder in reports ................................................................ 112
4.24 Trends analysis .................................................................................................. 117
Chapter 5 - Focus Groups .................................................................................................. 118
5.1 Rationale for Focus Groups ...................................................................................... 118
5.2 Focus Group Methods .............................................................................................. 120
5.21 Focus group sample size and composition ........................................................ 120
5.22 Focus group recruitment ..................................................................................... 121
5.23 Focus group instrumentation .............................................................................. 122
5.24 Data collection .................................................................................................... 122
5.25 Data analysis ...................................................................................................... 122
5.3 Focus Groups Results .............................................................................................. 125
5.31 Themes ............................................................................................................... 125
Chapter 6 - Semi-Structured Interviews ............................................................................. 135
6.1 Introduction ............................................................................................................... 135
6.2 Rationale for Semi-Structured Interviews ................................................................. 136
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6.3 Semi-Structured Interview Methods ......................................................................... 138
6.31 Semi-structured interview sample size and composition ................................... 138
6.32 Semi-structured interview recruitment ................................................................ 139
6.33 Semi-structured interview instrumentation ......................................................... 139
6.34 Data collection .................................................................................................... 139
6.35 Data analysis ...................................................................................................... 141
6.36 Methodological rigour within the qualitative studies ........................................... 143
6.4 Semi-Structured Interview Results ........................................................................... 149
6.41 Classification of personality disorder .................................................................. 149
6.42 Diagnostic process ............................................................................................. 155
6.43 Court process ..................................................................................................... 164
6.44 Impact of amendments to the Mental Health Act (1983) .................................... 168
6.45 Recommendations in reports .............................................................................. 170
6.46 Treatment ........................................................................................................... 181
6.47 Training and Experience ..................................................................................... 190
6.48 Stigma ................................................................................................................. 194
Chapter 7 - Discussion ....................................................................................................... 199
7.1 Methodological Issues and limitations ...................................................................... 199
7.2 Quantitative results ................................................................................................... 207
7.21 The prevalence of personality disorder .............................................................. 207
7.22 Correlations between domains and dimensions of personality disorder and
circumstances of the offence ...................................................................................... 209
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7.23 Factors associated with a diagnosis of personality disorder in reports .............. 211
7.3 Qualitative themes .................................................................................................... 214
7.31 Classification ....................................................................................................... 214
7.32 Diagnostic Process ............................................................................................. 217
7.33 Court Process ..................................................................................................... 219
7.34 Mental Health Act (1983) amendments .............................................................. 221
7.35 Recommendations within reports ....................................................................... 222
7.36 Treatment ........................................................................................................... 225
7.37 Training ............................................................................................................... 230
7.38 Stigma ................................................................................................................. 231
7.4 Implications and Future Developments .................................................................... 233
Bibliography ........................................................................................................................ 241
Appendices ......................................................................................................................... 263
Appendix 1: PAS DOC ................................................................................................... 263
Appendix 2: PAS DOC Algorithm ................................................................................... 307
Appendix 3: Focus group prompts .................................................................................. 309
Appendix 4: Semi- structured interview schedule .......................................................... 311
Appendix 5: Focus Group Participant Information Sheet ............................................... 313
Appendix 6: Semi-structured Interview Participant Information Sheet ........................... 316
Appendix 7: Consent form .............................................................................................. 319
Final word count: 70,512 words
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List of tables
Table 1 : Interrater reliability ratings for PAS-DOC variables ............................................. 100
Table 2: Prevalence of personality disorder and personality disturbance .......................... 102
Table 3: Frequencies of individual personality domains .................................................... 104
Table 4 Frequencies of severe and complex personality disorder ..................................... 106
Table 5 Univariate analysis for severe personality disorder: sociodemographic and historical
variables ............................................................................................................................. 107
Table 6 Univariate analysis for severe personality disorder: offence related variables ..... 108
Table 7 Variables independently associated with severe personality disorder from
multivariate analysis ........................................................................................................... 109
Table 8 Univariate analysis for complex personality disorder: sociodemographic and
historical variables .............................................................................................................. 110
Table 9 Univariate analysis for complex personality disorder: offence related variables ... 111
Table 10 Sociodemographic and Clinical factors associated with a diagnosis of personality
disorder in reports ............................................................................................................... 113
Table 11 Criminological factors associated with a diagnosis of personality disorder in
reports ................................................................................................................................. 114
Table 12: Offence related (victim) factors associated with a diagnosis of personality disorder
in reports ............................................................................................................................. 115
Table 13 Offence related (method) factors associated with a diagnosis of personality
disorder in reports ............................................................................................................... 116
Table 14 Focus group participants: demographic information and experience ................. 121
Table 15: Focus groups themes by participants and references ....................................... 124
Table 16: Semi- structured interview participants: demographic information and experience
............................................................................................................................................ 138
Table 17: Semi-structured interview themes by participants and references .................... 142
Table 18: Measure of quality in this study .......................................................................... 145
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List of Figures
Figure 1: DSM IV classification of Antisocial Personality Disorder (American Psychiatric
Association 1994) ................................................................................................................. 29
Figure 2: ICD10 Classification of Dissocial Personality Disorder (World Health Organisation
1992) ..................................................................................................................................... 30
Figure 3: Concurrently conducted mixed methods studies .................................................. 86
Figure 4: Sequentially conducted mixed methods studies ................................................... 86
Figure 5 Degree of overlap between personality domains* ............................................... 105
Figure 6: Reports with diagnosis of personality disorder, year on year ............................. 117
Figure 7: Focus groups themes .......................................................................................... 126
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Abstract
Background
The National Confidential Inquiry into Suicide and Homicide by People with
Mental Illness has been collecting detailed clinical data since 1996 on a national
sample of people who commit homicide, including psychiatric reports prepared
for court. From 1996-2006, the Inquiry was notified of 5808 homicides in
England and Wales. A diagnosis of personality disorder was made in 16% (406)
of cases in psychiatric reports prepared for court. Given prevalence figures of
50-90% for personality disorder in the offender population in general, it seems
likely that this is an underestimation in this population.
Aims
Estimate the prevalence of personality disorder in a national case series of
homicide perpetrators with court reports. Investigate any variables associated
with the diagnosis of personality disorder in court reports, and with specific
dimensions of personality disorder. Explore potential reasons for the lack of
attribution of a personality disorder diagnosis in reports.
Method
600 court reports were analysed using the PAS-DOC, a document derived
version of the Personality Assessment Schedule. Those with a diagnosis of
personality disorder in reports were compared with those without on a number
of sociodemographic, clinical, and criminological variables Focus groups and
semi structured interviews were conducted with Forensic Psychiatrists with a
range of experience to explore attitudes towards personality disorder.
Results
The prevalence of personality disorder in this sample was 56.3% (95% CI
52.3% - 60.3%). Perpetrators with previous violent offences and substance
misuse were more likely to be diagnosed with personality disorder by report
writers. Severe personality disorder was significantly associated with prior
convictions for any violent offences and with a stranger as a victim. Complex
personality disorder was associated with a family or spouse as a victim, and
negatively associated with a stranger as a victim. A number of themes emerged
in the focus groups and semi-structured interviews to explain the discrepancy
between the identified prevalence of personality disorder and its diagnosis
made by report writers. These included issues surrounding classification,
comorbid mental illness, ethical issues regarding court, recommendations for
verdict and disposal, treatability, service provision, training and stigma.
Conclusions
Personality disorder is underdiagnosed in psychiatric reports prepared for court.
Reasons for this and the implications from both a clinical and ethical
perspective are discussed.
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Declaration
No portion of the work referred to in the thesis has been submitted in support of an
application for another degree or qualification of this or any other university or other institute of
learning.
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