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Title Substance misuse in young people in Ireland - a focus on benzodiazepines
Author(s) Murphy, Kevin D. Publication date 2014 Original citation Murphy, K. 2014. Substance misuse in young people in Ireland - a focus on benzodiazepines. PhD Thesis, University College Cork.
Type of publication Doctoral thesis Rights © 2014, Kevin Murphy. http://creativecommons.org/licenses/by-nc-nd/3.0/
Embargo information No embargo required
Item downloaded http://hdl.handle.net/10468/1903 from Downloaded on 2021-10-07T17:21:14Z
Substance Misuse in Young People in Ireland - A Focus on Benzodiazepines
Kevin Murphy BPharm (Hons) MPSI
A thesis submitted to the National University of Ireland, Cork for the degree of Doctor of Philosophy in the School of Pharmacy
June 2014
Head of School
Prof. Stephen Byrne
Supervisors
Prof. Stephen Byrne
Dr. Laura Sahm
Dr. Suzanne McCarthy
Overview of Contents
Declaration ...... ii
Table of Contents ...... iii
Table of Figures ...... viii
Table of Tables ...... ix
Table of Equations ...... x
Table of Abbreviations ...... xi
Publications...... xi
Thesis Abstract ...... xvi
Acknowledgements ...... xxi
Chapter 1 - Thesis Introduction ...... 1
Chapter 2 - Substance use in young persons in Ireland, a systematic review30
Chapter 3 - Benzodiazepine prescribing guideline adherence and misuse potential in Irish minors ...... 68
Chapter 4 - Use of addiction treatment services by Irish youth: does place of residence matter? ...... 94
Chapter 5 - Benzodiazepine use amongst young attendees of an Irish substance treatment centre ...... 108
Chapter 6 - “You Don’t Feel” – The Experience Of Youth Benzodiazepine Misuse ...... 125
Chapter 7 -“They’re too good” - Health-care worker views on youth benzodiazepine misuse ...... 169
Chapter 8 - Thesis Discussion ...... 204
Chapter 9 - References ...... 218
Appendices ...... 242
i
Declaration
I declare that this thesis has not been previously submitted for a degree at this, or any other university. It is entirely my own work, apart from due acknowledgement. The library may lend or copy this thesis upon request.
Signed:______Date:______
ii
Table of Contents
Table of Contents ...... iii
Table of Figures ...... vi
Table of Tables ...... vii
Table of Equations ...... viii
Table of Abbreviations ...... ix
Publications...... xi
Thesis Abstract ...... xvi
Introduction ...... xvi
Methods ...... xvi
Results ...... xviii
Conclusion ...... xx
Acknowledgements ...... xxi
1. Thesis Introduction ...... 1
1.1 Drugs Policy in Ireland ...... 2
1.2 Defining addiction and dependence ...... 7
1.3 Diagnosing dependence ...... 9
1.4 Psychological dependence ...... 13
1.5 Physiology of psychological dependence ...... 16
1.6 Physical dependence ...... 20
1.7 Mechanisms of action of misused substances ...... 23
1.8 Summary ...... 29
2. Substance use in young persons in Ireland, a systematic review ...... 30
2.1 Introduction ...... 31
2.2 Methods ...... 34
2.3 Results...... 39 iii
2.4 Discussion ...... 60
3. Benzodiazepine prescribing guideline adherence and misuse potential in Irish minors ...... 68
3.1 Introduction ...... 69
3.2 Methods ...... 71
3.3 Results...... 77
3.4 Discussion ...... 87
4. Use of addiction treatment services by Irish youth: does place of residence matter? ...... 94
4.1 Introduction ...... 95
4.2 Methods ...... 98
4.3 Results...... 101
4.4 Discussion ...... 105
5. Benzodiazepine use amongst young attendees of an Irish substance treatment centre ...... 108
5.1 Introduction ...... 109
5.2 Methods ...... 112
5.3 Results...... 113
5.4 Discussion ...... 120
6. “You Don’t Feel” – The Experience Of Youth Benzodiazepine Misuse125
6.1 Introduction ...... 126
6.2 Method ...... 128
6.3 Results...... 133
6.4 Discussion ...... 159
7. “They’re too good” - Health-care worker views on youth benzodiazepine misuse ...... 169
7.1 Introduction ...... 170
7.2 Method ...... 171
iv
7.3 Results...... 175
7.4 Discussion ...... 194
8. Thesis Discussion ...... 204
8.1 Discussion ...... 205
8.2 Limitations ...... 215
8.3 Future Work ...... 216
9. References ...... 218
10. Appendices ...... 242
10.1 Appendix I - Controlled drugs schedules in Ireland ...... 243
10.2 Appendix II - Draft Misuse of Drugs (Amendment) Regulations, 2013...... 255
10.3 Appendix III – Substance use in young persons in Ireland ...... 268
10.4 Appendix IV – MINORS rating of reviewed studies ...... 279
10.5 Appendix V – Ethical approval for study in Chapter 3 ...... 281
10.6 Appendix VI – Ethical approval for studies in Chapter 4 and 5 ... 283
10.7 Appendix VII – Sample National Drug Treatment Reporting System form...... 285
10.8 Appendix VIII – Sample Initial Assessment form ...... 287
10.9 Appendix IX – Ethics approval for Chapter 6 research ...... 295
10.10 Appendix X – Information sheet and consent form for Chapter 6 research ...... 299
10.11 Appendix XI – Ethical approval for Chapter 7 research ...... 302
10.12 Appendix XII – Information sheet and consent form for Chapter 7 research ...... 306
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Table of Figures
Figure 1.1. Schematic diagram of the human brain that highlights some of the main brain areas and neurotransmitter pathways implicated in reward processes ...... 17 Figure 1.2. Action of selected dependence-forming substances in the mesolimbic system ...... 18 Figure 1.3. GABA receptors in the mesolimbic dopaminergic systems involved in addiction ...... 26 Figure 2.1. Adapted from the PRISMA flow diagram ...... 40 Figure 3.1.Benzodiazepine consumption in selected European countries between 2009 and 2012 ...... 79 Figure 3.2. Benzodiazepine prescribing between 2009 and 2012 by age ..... 82 Figure 5.1. Number of service-user forms filled out by year ...... 114
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Table of Tables
Table 1.1. ICD-10 diagnostic criteria for substance dependence ...... 10 Table 1.2. DSM-IV-TR diagnostic criteria for substance dependence ...... 11 Table 1.3. DSM-IV-TR diagnostic criteria for substance abuse...... 12 Table 2.1. Summary of study characteristics ...... 37 Table 2.2. Summary of smoking prevalence rates ...... 42 Table 2.3. Summary of alcohol prevalence rates ...... 49 Table 2.4. Summary of cannabis prevalence rates ...... 54 Table 2.5. Summary of benzodiazepine prevalence rates ...... 59 Table 3.1. Background statistics of patients issued benzodiazepines between 2009 and 2012 ...... 80 Table 3.2. Benzodiazepine prescribing between 2009 and 2012 ...... 81 Table 3.3. Compliance to benzodiazepine guideline 1 ...... 84 Table 3.4. Compliance to benzodiazepine guideline 2 ...... 85 Table 3.5. Compliance to benzodiazepine guideline 3 ...... 86 Table 4.1. Comparison of demographics between urban and rural service- users ...... 102 Table 4.2. Comparison of substance use between urban and rural service- users ...... 104 Table 5.1. Breakdown of referrals of service users by source of referral .... 114 Table 5.2. Service-users who have ever used a substance ...... 115 Table 5.3. Comparison of service-user characteristics of regular and non- regular benzodiazepine users ...... 116 Table 5.4. Comparison of physical and behavioural symptoms experienced by benzodiazepine users ...... 118 Table 6.1. Street names for benzodiazepines ...... 133 Table 6.2. Themes and categories discussed in interviews ...... 134 Table 7.1. Themes and categories discussed in interviews ...... 176
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Table of Equations
Equation 3.1. DDD/1,000/day calculation ...... 76
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Table of Abbreviations
AIDS Acquired Immune Deficiency Syndrome CBT Cognitive Behavioural Therapy CINAHL Cumulative Index to Nursing and Allied Health Literature COREQ Consolidated criteria for reporting qualitative research CREC Cork Ethics Research Committee CSO Central Statistics Office DA Dopamine DAT Dopamine Active Transporter DDD Defined Daily Dose DPS Drug Payment Scheme Diagnostic and Statistical Manual of Mental Disorders 4, Text DSM-IV-TR Revision EMCDDA European Monitoring Centre for Drugs and Drug Addiction ERIC Education Resources Information Centre ESPAD European School Survey Project on Alcohol and Other Drugs EU European Union GABA gamma-aminobutyric acid GMS General Medical Services GP General Practitioner HII Health Intelligence Ireland HRB Health Research Board HSE Health Service Executive ICD International Classification of Diseases IQR Interquartile Range JLO Juvenile Liaison Officer LSD Lysergic Acid LTI Long Term Illness MDMA methylenedioxymethamphetamine MeSH Medical Subject Headings MINORS Methodological Index of Non-Randomised Studies
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MOR Mu Opioid Receptors MTS Matt Talbot Services NAc Nucleus Accumbens NACD National Advisory Council on Drugs NDTRS National Drug Treatment Reporting System NHS National Health Service NICE National Institute of Clinical Excellence NMDA N-methyl-D-aspartate PCRS Primary Care Reimbursement Service PFC Prefrontal Cortex PKC Protein Kinase C Preferred Reporting Items for Systematic Reviews and Meta- PRISMA analyses RCT Randomised Control Trial SAMSHA Substance Abuse and Mental Health Services Administration SD Standard Deviation SPC Summary of Product Characteristics SPHE Social Personal and Health Education SUDS Substance Use Disorder Syndrome THC Tetrahydrocannabinol UNICEF United Nations Children's Fund USA United States of America VTA Ventral Tegmental Area WHO World Health Organisation World Health Organisation - Anatomical Therapeutic Chemical WHO-ATC Classification System YC Youth Counsellor
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Publications
Peer-reviewed publications
. Murphy KD, McCarthy S, Byrne S, Lambert S, Sahm L.
Benzodiazepine use amongst young attendees of an Irish substance
treatment centre. Journal of Addiction Medicine. 2014;In Press.
. Murphy KD, Byrne S, Sahm L, Lambert S, McCarthy S. Use of
addiction treatment services by Irish youth: does place of residence
matter? Rural and Remote Health. 2014;In Press.
. Parsons C, McCorry N, Murphy K, Byrne S, O'Sullivan D,
O'Mahony D, Passmore P, Patterson S, Hughes C. Assessment of
factors that influence physician decision making regarding medication
use in patients with dementia at the end of life. International Journal of
Geriatric Psychiatry. 2013;29(3):281-90.
. Murphy K, Sahm L, McCarthy S, Lambert S, Byrne S.
Substance use in young persons in Ireland, a systematic review.
Addictive Behaviors. 2013;38(8):2392-401.
. O'Sullivan DP, O'Mahony D, Parsons C, Hughes C, Murphy K,
Patterson S, Byrne S. A prevalence study of potentially inappropriate
prescribing in irish long-term care residents. Drugs Aging. 2013
Jan;30(1):39-49.
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Peer-reviewed published abstracts
. Murphy K, Sahm L, Lambert S, Byrne S. A survey of service-
users attending Matt Talbot Services (MTS) during 2009 and their use
of alcohol. International Journal of Clinical Pharmacy. 2012;34(1):231.
. Murphy KD, Sahm L, Lambert S, Byrne S. A descriptive
analysis of service-users attending an outpatient treatment centre
during 2009/2010. International Journal of Pharmacy Practice.
2012;20(S1):19-20.
Published reports
. Parsons C, McCorry N, Hughes C, Passmore P, Patterson S,
Olver A, Kennedy G, Megraw V, Byrne S, O' Mahony D, O' Sullivan D,
Murphy K, Hickey M, Collins U. Assessment of factors which influence
physician decision-making regarding medication use in patients with
dementia at the end of life. Dublin/Belfast: Centre for Ageing
Research and Development in Ireland, 2012.
Presentations and Posters
. School of Pharmacy Scientific Conference, University College
Cork
School of Pharmacy, University College Cork, Cork, 27th September
2013
Poster: Adolescent benzodiazepine use and its health effects
Murphy, K., Byrne, S., McCarthy, S., Sahm, L., Lambert, S.
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. Association for Children and Adolescent Mental Health
Research Day 2013
St James’s Hospital, Dublin, 17th May 2013
Poster: Adolescent benzodiazepine use and its health effects
Murphy, K., Byrne, S., McCarthy, S., Sahm, L., Lambert, S.
. European Society of Clinical Pharmacy 2012
Hotel Fira Palace, Barcelona, Spain, 28th-31st October 2012
Poster: Substance Use in Young Persons in Ireland, a Systematic
Review
Murphy, K., Sahm, L., Lambert, S., Byrne, S.
Poster: Analysis of service-users attending Matt Talbot Services
(MTS) from 2007-2010
Murphy, K., Sahm, L., Lambert, S., Byrne, S.
. Health Services Research & Pharmacy Practice 2012
School of Pharmacy, University College Cork, Cork, 24th April 2012
Presentation: A descriptive analysis of service-users attending an outpatient treatment centre during 2009/2010
Murphy, K., Sahm, L., Lambert, S., Byrne, S.
xiii
. All-Ireland Schools of Pharmacy 2012
School of Pharmacy, University College Cork, Cork, 2nd April 2012
Presentation: A descriptive analysis of service-users attending an outpatient treatment centre during 2007-2010
Murphy, K., Sahm, L., Lambert, S., Byrne, S.
Poster: A survey of service-users attending Matt Talbot Services during 2009 and their use of alcohol
Murphy, K., Sahm, L., Lambert, S., Byrne, S.
. European Society of Clinical Pharmacy 2011
Dublin, Ireland, 19th -21st October 2011
Poster: A survey of service-users attending Matt Talbot Services during 2009 and their use of alcohol
Murphy, K., Sahm, L., Lambert, S., Byrne, S.
. Postgraduate Annual Presentation 2011
School of Pharmacy, University College Cork, Cork, 15th September
2011
xiv
Presentation: The Evaluation of Substance Use in Adolescents in
Cork
Murphy, K., Sahm, L., Lambert, S., Byrne, S.
Postgraduate Taught Module Credits Awarded
. PG6024 - Qualitative Research Inquiry
Credit weighting: 5
Award date: 10th December 2013
. ST6013 - Statistics and Data Analysis for Postgraduate
Research Students, awarded Credit weighting: 10
Award date: 7th October 2013
. PG6003 - Teaching and Learning for Graduate Students
Credit weighting: 5
Award date: 5th March 2012
. PG6001 - Scientific Training for Enhanced Postgraduate Study
Credit weighting: 5
Award date: 29th February 2012
. PG6009 - Graduate Information Literacy Skills
Credit weighting: 5
Award date: 20th June 2011
xv
Thesis Abstract
Introduction Substance misuse in Ireland has a long history. Alcohol was recognised as the main concern, but it was not until the 1960s that other dependence- forming substances have been recognised as problematic in Ireland. Since then, the number of misused substances has risen sharply to include novel synthetic compounds and prescription-only medicines. Many attempts have been made to reduce the misuse of these substances: restricting growth and manufacture of substances, criminalising possession, increasing prescribing requirements, and using treatment centres to assist those who wish to stop misusing. Despite enormous expense and effort, substance misuse is still a problem. The mechanism by which these substances excite the brain’s natural reward pathways means it can be difficult for misusers to stop desiring the effects of the substances. Much has been discovered about how misused substances create their dependence-forming effect, but there is still much unsolved in such a complex area.
Methods A systematic review was undertaken on the prevalence of substance misuse amongst young people in Ireland between 2000 and 2012 to create a context in which later research among substance misusers can be compared, and to put benzodiazepine misuse in the context of other misused substances.
xvi
Data from national reimbursement claims were analysed to examine trends in: (i) the prescribing of benzodiazepines nationally and internationally and
(ii) the prescribing of benzodiazepines to patients younger than 18 years between 2009 and 2012, to monitor adherence to benzodiazepine prescribing guidelines and to highlight areas in prescribing where the potential for misuse could be decreased.
The differences between urban and rural attendees of a substance misuse treatment centre in Cork were compared to examine whether there were differences in substance misuse between the groups. This was followed by a comparison of regular and non-regular benzodiazepine misusers from the substance misuse treatment centre and their self-reported misuse-related symptoms.
The next stage involved qualitative research using semi-structured interviews with young people who had misused benzodiazepines in their adolescence.
This approach was used to describe the experiences and causes of youth benzodiazepine misuse in Cork and to guide future interventions to reduce misuse. This approach was also utilised for interviews conducted with youth counsellors (YCs) and general practitioners (GPs). As substance misuse in adolescence can lead to damaged brain development, which may result in a lack of insight into their behaviours, it was important to gain this information from those who have worked with young benzodiazepine misusers.
xvii
Results The systematic review returned 18 articles that matched the inclusion criteria for the study. The review showed that tobacco, alcohol and cannabis use levels in Ireland have reduced in the period between 2000 and 2012. Lifetime tobacco use reported at the beginning of the review period ranged from approximately 61-67%, and decreased to 43-48% at the end of the study period. Lifetime alcohol levels similarly decreased from 71-92% at the beginning of the review period to 58-81%. Lifetime cannabis misuse decreased from 29-39% to approximately 18%. Lifetime benzodiazepine misuse was the only parameter which did not decrease over the study period. Research conducted into the comparison of Irish prescribing data relative to European counterparts found that Ireland had the fourth highest level of benzodiazepine prescribing among those countries surveyed between 2009 and 2012. However Irish prescribing did decrease by 16% over this time. Approximately 15% of Irish people aged 17 and under were prescribed benzodiazepines for greater than four weeks, whilst approximately 40% were prescribed hypnotics, both in contravention of the
Good Practice Guideline for Clinicians.
Data comparing urban and rural treatment centre attendees showed that a greater percentage of rural service-users were employed (p = 0.015), more urban service-users were unemployed (p = 0.015), while there were similar levels of students from urban and rural areas. A greater proportion of urban service-users had taken multiple substances in their lifetime (73.7% vs.
xviii
52.2%, p = 0.001) and continued to use multiple substances regularly (49.3% vs. 31.3%, p = 0.003) compared with their rural counterparts. The study comparing regular and non-regular benzodiazepine usage showed that benzodiazepines had ever been used by 51.0% treatment centre attendees, and of these, 55.8% were regular benzodiazepine users. The mean age of first use was 14.9 ± 1.4 years.