Adolescent Addiction Course Module 2 Thurs 27 January 2005 Epidemiology of substance abuse in young

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Adolescent Addiction Course Module 2 Thurs 27
January 2005 Epidemiology of substance abuse in
young people
Martin Frisher Department of Medicines
Management Keele University Harplands Hospital
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Topics covered in Module 1

• Define Epidemiology, Adolescence and Drug
  Use/Addiction
• Epidemiology-Basic Concepts
• Brief look at different models of (adolescent)
  drug use
• Characteristics of current adolescent drug use
• UK vs. European adolescent drug use
• Effects of early life experience
• Subjective experience of drug use
• Does early drug use act as a gateway to hard
  drug use?

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Learning Objectives

• Epidemiological methods used to study substance
  abuse in young people
• Licit and illicit drug use among young people in
  the UK variation by age and gender
• Statutory Statistics
• Data Analysis and Interpretation
• The Gateway Effect from cannabis to other
  drugs, psychiatric illness and crime

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Epidemiological Issues
1. Research designs. 2. Quantitative or
qualitative? 3. Samples, populations, data,
outcome measures. 4. Sources of bias in research
design.
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Types of Research Design

• laboratory, experimental
• non-experimental intervention (RCT/non RCT)
• population survey
• subgroup survey
• qualitative study
• case study
• review (systematic, selective)

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Research Paradigms
Cohen, L, Manion, L. Morrison, K.(2000).
Research Methods in Education, 5th Ed, Routledge
Falmer.
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Criticism of both paradigms

• Positivism
• Main focus on the methods and the data (the data
  speak for themselves)
• Emphasis on verification and empirical validation
  at the expense of discovery
• Theoretical complexity reduced to banality
• Interpretivism
• Extreme subjectivity rules out the very existence
  of science
• Too much focus on individual prevent
  generalization
• Such knowledge can not be objective

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Research Methods used inDrug Abuse Research

• Observational/Unstructured Methods
• Clinical Methods
• Survey/ Epidemiological Methods
• Experimental Methods

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Research Questions and Methods

• What is the prevalence of a given disease?
• What are the risk factors for a given disease?
• How prevalent are the behavioural risk factors
  for a given disease?
• How effective are psychological and behavioural
  interventions for a given disease?

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Key Epidemiological Concepts

• Prevalence/Incidence
• Morbidity/Mortality
• Relative risk/Attributable risk

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Drugs offered, tried and regular use ()School
Survey 2001
( ) any drug excluding volatile substances
Drug use, smoking and drinking among young people
in England in 2003 National Centre for Social
Research/National Foundation for Educational
Research
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British Crime Survey 2002Age 16-24
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Drug use, smoking and drinking amongyoung people
aged 11-15 in England in 2003National Centre
for Social Research/National Foundation for
Educational Research
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Smoking

• Prevalence of regular smoking (at least one
  cigarette a week) decreased from 10 in 2002 to
  9 in 2003
• There is an increase in prevalence of smoking
  with age - 1 of 11 year olds smoke regularly
  compared with 22 of 15 year olds.
• Smoking was reported by 16 of 14 year old girls
  and 26 of 15 year old girls, compared with 9 of
  14 year old boys and 18 of 15 year old boys.
• Higher prevalence of smoking among girls than
  boys was found among all ages except age 11 where
  only 1 smoked regularly.

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Prevalence of drinking in previous week
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Drinking

• Prevalence of drinking alcohol in the last week
  was 25 in 2003. This figure rose steadily from
  20 in 1988
• Boys continued to be more likely than girls to
  have drunk alcohol in the last week in 2003 (26
  compared with 24)
• As with cigarette smoking, prevalence of drinking
  increased with age in 2003, 6 of all pupils
  aged 11 had had a drink in the last week, while
  49 of 15 year olds had done so.

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Alcohol Consumption

• In terms of the amount of alcohol drunk, the
  average weekly consumption among pupils who drank
  in the last 7 days increased from 5.3 units in
  1990 to 9.9 units in 1998, and has fluctuated
  around this level since then.
• In 2003, the average weekly consumption was 9.5
  units.

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Units of Alcohol
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Drug Use, Last Year-1998-2003
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Drug Use, Last Month-1998-2003
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Drugs-Frequency

• 1 of pupils took drugs most days, a further 2
  took drugs at least once a week, and a further 3
  took drugs once or twice a month.
• Cannabis was by far the most likely drug to have
  been taken 13 of pupils aged 11-15 had taken
  cannabis in the last year.
• 8 reported taking volatile substances in the
  last year in 2003.

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Drugs-Frequency

• Among 11 and 12 year olds, misuse of volatile
  substances in the last year was more common than
  taking cannabis.
• 6 of 11 year olds had sniffed volatile
  substances in the last year and 1 had taken
  cannabis. The equivalent figures for 12-year-olds
  were 7 and 3.
• 1 of 11-15 year olds had taken heroin in the
  last year and 1 had taken cocaine in the last
  year. In total, 4 had taken Class A drugs in the
  last year.

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Trends

• 21 of pupils had taken drugs in the last year in
  2003, an increase from 20 in 2002 and 2001
• 12 of pupils had taken drugs in the last month
  in 2003, the same proportion as in 2002 and 2001.
• 9 of pupils aged 11-15 were regular smokers in
  2003, a decrease from 10 in 2002
• The proportion of pupils who drank in the last
  week was 25 in 2003, there was no significant
  change from last year (24 in 2002)

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Europe Cannabis Use at age 15
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Cannabis Use by Birth Cohort
Data EMCDDA
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Europe Amphetamines, Ecstasy and Cocaine Use at
age 15
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Europe HIV prevalence among injecting drug users

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Europe, treatment primary drug
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Criminal JusticeDrug Possession Offences Age
Possession Offences 2002 95,000
Supply Offences 2001 5000
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UK Drug Seizures Trends
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Regional Drug Misuse Databases in Englandnumber
of new or renotified clients 1993 and 2001
The number of users reported as being in
treatment with drug misuse agencies and GPs was
around 118,500. About one-third (32) of users in
treatment were under 25 (38,000).
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Treatment, age and gender
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Treatment main drugs
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Precursors and consequences of problematic drug
use A study of young people accessing designated
drug services

• Previous research indicates that young people who
  access drug services have problems in multiple
  domains (psychological, physical, familial and
  environmental) in addition to their identified
  substance misuse.
• However there has been little progress within a
  UK context in understanding how these risk
  factors are linked.
• The primary aim of the study was to define the
  hierarchy of risk and protective factors among
  the adolescents attending designated drug
  services and to understand the direct and
  indirect links between these factors
• The study employed Structural Equation Modelling
  (SEM) to develop path diagrams

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Example of SEM
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Potential Risk Factors
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Stoke/Newcastle Study of Adolescent Drug Users
Age at Interview and LPDU
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Age at First Use
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Influence of Age
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Univariate
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Univariate
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Univariate
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Structural Equation ModelPrecursors of the level
of drug use
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Deprivation and Substance Use
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Social variables NOT linked to level of
problematic drug use

• material deprivation (Townsend score)
• perceived safety or vandalism of neighbourhood
• regular parental drinking or parental smoking
• being expelled from school
• being bullied or bullying others
• living with foster parents
• living in residential care
• serious illness in the past

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Summary of Model Effects
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Hierarchy of risk?
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Parenting

• When experiencing problems of whatever nature,
  it is easy to feel alone, not knowing who to turn
  to for help. This was my experience before I was
  introduced to the Parenting programme by the YOT.
  There was no light at the end of the tunnel for
  me and life seemed to be in a downward spiral.
  But once I joined the group I soon realised that
  I was not alone and that there were other parents
  who were experiencing the same and often worse
  problems than myself.
• After a short time I began to look at my life
  from a different perspective. My relationship
  with my son changed, as did my attitude. As no
  one taught us to be parents, sometimes it is
  difficult to know how to react when faced with
  problems.

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Qualitative Research

• One of the potential advantages of the
  quantitative approach is the opportunity to
  assess variables which respondents might not
  think was causally associated with their drug use
  (e.g. perception of parental controls).
• Furthermore people are adept at finding reasons
  for their behaviour which may not accord with the
  actual causes (i.e. poor exam performance
  explained by not feeling well).
• Interestingly, Measham et al. note that The
  experience of the Manchester University research
  team, and that of other qualitative researchers,
  suggests that respondents are not always aware of
  the reasons why they do or do not engage in
  certain behaviours

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LPDU and the number of problems before and after
drug use.
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Consequences of drug use
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Further research

• Using the model as a framework for qualitative
  study. For example, the model highlights the
  importance of the variable running away from home
  yet this was only measured by a simple yes/no
  response.
• Similarly with friends use of drugs. Did these
  friends predate initiation into drug use, or did
  the respondent gravitate towards friends who were
  already drug users.
• Exploring personality and social factors in
  quasi-experimental settings. The field of
  cognitive social psychology offers numerous
  paradigms which could be used to explore drug
  users behaviour

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Intergroup processes

• The role of identification within a group has
  been examined by Tajfel (1978). In his analysis,
  issues of intergroup relations turn on the
  individual sense of belonging to, or
  identification within his/her group
• An interesting application of Tajfels theory
  relates to groups that find themselves
  disadvantaged in terms of one dimension. Such
  groups will look for new comparisons to achieve a
  positive identity

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Qualitative Research

• Moving from experimentation with illicit drugs
  in the early teens to dance drugs and the Class
  As was seen as a sign of maturity both inherent
  in the image of the individual drugs themselves
  and also practically in the drugs effects.
• The continuation of drug use after an initial
  experience depended not only on the perceived
  positive and negative effects of the drug itself
  but also on how the drug trier learned to
  identify and interpret those effects.

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Prevention

• These data could be used to argue that prevention
  activities should be directed and initiated in
  early adolescence. Among this sample, early
  experimentation with drugs at age 13 invariably
  led to problematic drug use involving heroin and
  cocaine at age 16.
• One possible argument against early intervention
  is that the age of onset only has a small impact
  on LPDU. Another argument against early
  intervention is that there are difficulties in
  trying to prevent a behaviour (i.e. problematic
  drug use) which has not yet occurred. As higher
  levels of problematic drug use seem to develop
  around the age of 15-16, attempts to modify
  behaviour at 15/16 may be more productive.

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Adolescent Substance Use and Later Outcomes

• Weak association between substance abuse in
  adolescence and a variety of outcome measures in
  young adulthood (Newcomb, Bentler Consequences
  of Adolescent Drug Use, Sage 1988)
• Adolescents who experiment with psychoactive
  drugs have healthier psychological outcomes than
  did either frequent users or abstainers (Shedler
  J, Block J. American Psychologist 1990, 45,
  612-630).

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Adolescent Drug Use and Psychological HealthA
Longitudinal InquiryJonathan Shedler and Jack
Block

• Findings span 13 years, from preschool through
  age 18.
• In the present study, psychological descriptions
  are comprehensive and open-ended.
• Previous investigators have tended to assume (and
  test for) linear relations between level of drug
  use and measures of psychosocial disturbance.
• In effect, such an approach assumes that
  occasional experimentation with drugs is
  psychologically problematic, if not quite as
  problematic as regular use, and that complete
  avoidance of drugs is psychologically optimal

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Adolescent Drug Use and Psychological HealthA
Longitudinal Inquiry

• Abstainers were defined as subjects who had never
  tried marijuana or any other drug. This group
  contained 29 subjects, 14 boys and 15 girls.
• Experimenters were defined as subjects who had
  used marijuana "once or twice," "a few times," or
  "once a month," and who had tried no more than
  one drug other than marijuana. This group
  contained 36 subjects, 16 boys and 20 girls. The
  mean number of other drugs tried by the subjects
  in this group was 0.31 (i.e., 11 of the 36
  subjects had tried one drug other than
  marijuana).
• Frequent users were defined as subjects who
  reported using marijuana frequently, that is,
  once a week or more, and who had tried at least
  one drug other than marijuana. This group
  contained 20 subjects, 11 boys and 9 girls. The
  mean number of other drugs tried by the subjects
  in this group was 2.7

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Adolescent Drug Use and Psychological HealthA
Longitudinal InquiryDesign

• many studies to date have been interpretively
  constrained by various research-design or
  empirical limitations.
• Epidemiological studied have been unable to
  provide the kind of in depth, psychologically
  rich, clinically oriented information needed to
  inform intervention efforts.
• And by their very nature, cross-sectional studies
  and panel studies of relatively brief duration
  can offer only limited or confounded
  understandings of the antecedents of drug use.

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Adolescent Drug Use and Psychological HealthA
Longitudinal InquiryResearch Design

• Subjects were 101 18-year-olds, 49 boys and 52
  girls, from an initial sample of 130
  participating in a longitudinal study of ego and
  cognitive development
• assessed on wide-ranging batteries of
  psychological measures at ages 3, 4, 5, 7, 11,
  14, and 18
• Information about drug use was collected at age
  18 during individual interviews with the
  subjects. Skilled clinicians conducted these
  interviews, which ranged over a variety of topics
  including schoolwork, peer relations, family
  dynamics, personal interests, dating experiences,
  and so on. Total interview time was typically
  four hours per subject, and all interviews were
  videotaped .

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Adolescent Drug Use and Psychological HealthA
Longitudinal Inquiry

• Psychological differences between frequent drug
  users, experimenters, and abstainers could be
  traced to the earliest years of childhood and
  related to the quality of parenting received.
• Findings indicate that (a) problem drug use is a
  symptom, not a cause, of personal and social
  maladjustment, and (b) the meaning of drug use
  can be understood only in the context of an
  individual's personality structure and
  developmental history.
• Suggest that current efforts at drug prevention
  are misguided to the extent that they focus on
  symptoms, rather than on the psychological
  syndrome underlying drug abuse.

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Abstainers

• Relative to experimenters, abstainers are
  described as fastidious, conservative, proud of
  being "objective" and rational, overcontrolled
  and prone to delay gratification unnecessarily,
  not liked or accepted by people, moralistic,
  unexpressive, prone to avoid close interpersonal
  relationships, predictable in attitudes and
  behavior, not gregarious, not able to enjoy
  sensuous experiences, basically anxious, not
  straightforward and forthright with others, not
  physically attractive, not personally charming,
  and not socially at ease

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Discussion

• Data indicate that drug use and drug abstinence
  have theoretically coherent antecedents and must
  be understood within the context of an
  individual's total psychology.
• In the case of experimenters, drug use appears to
  reflect age appropriate and developmentally
  understandable experimentation.
• In the case of frequent users, drug use appears
  to be a manifestation of a more general pattern
  of maladjustment, a pattern that appears to
  predate adolescence and predate initiation of
  drug use.

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Discussion

• Not suggesting that the inverted U-shaped
  relation between level of drug use and
  psychological health expresses a fundamental
  psychological principle or law.
• Rather, a function of historical and social
  circumstances-specifically, of the current
  prevalence of drug use in this culture, conjoined
  with the developmentally appropriate propensity
  of adolescents to explore and experiment

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Gateway from cannabis to...

• Many hard drug users have followed a similar path
  from cigarettes and alcohol, to cannabis, to
  heroin and cocaine.
• This has led some researchers to argue that soft
  drugs provide a "gateway" to harder substances.
• It might be that cannabis users have a genetic
  profile that predisposes them both to cannabis
  use and to harder drugs, or a personal history
  that does the same.

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Survey Data Cannabis and Cocaine

• An American study determined that from the
  population of cannabis users 17 had used cocaine
  whereas from the population of non-cannabis users
  only 0.2 had used cocaine.
• The vast majority of cannabis users (83) do not
  go on to use cocaine. The study actually shows
  the opposite of what it is often purported to
  prove in effect, for most users, cannabis is
  'clearly a "terminus" rather than a "gateway"
  drug'www.ukcia.org/culture/effects

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Twins Study Supports 'Gateway Theory'

• 311 sets of same-sex twins in which only one twin
  had smoked marijuana before age 17.
• Early marijuana smokers were found to be up to
  five times more likely than their twins to move
  on to harder drugs
• Associations between early cannabis use and later
  drug use and abuse/dependence cannot solely be
  explained by common predisposing genetic or
  shared environmental factors.
• cannabis may change your brain or makes you crave
  other drugs
• other potential mechanisms, including access to
  drugs, willingness to break the law and
  likelihood of engaging in risk-taking behavior.
• Escalation of Drug Use in Early-Onset Cannabis
  Users vs Co-twin Controls JAMA, Jan 2003 289
  427 - 433.

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The governments Updated Drug Strategy (December
2002)

• government will be targeting action on the most
  dangerous drugs and patterns of drug use and the
  most vulnerable young people
• the most effective way of reducing the harm
  drugs cause is to persuade all potential users,
  but particularly the young not to use drugs