Blattler et al 2002
- Heroin maintenance programme – Switzerland
Aim
- To see whether supplying heroin on a medical programme, combined with therapy, would reduce cocaine use among participants
Sample
- 266 heroin addicts who also take cocaine
- 168 male – 98 female
- Original sample was 995 but some dropped out
- Informed consent was given
- Been on heroin for at least 2 years
- Average heroin use = 10 years
- Average cocaine use = 7 years
- All had at least 2 attempts at being treated but were unsuccessful
- Mean age = 30
- 75% preferred injecting both heroin and cocaine
- 33% drank alcohol
- 30% were daily cocaine users
- 23% smoked cannabis
- 54% occasionally used cocaine
- 16% non-cocaine users at intake
Procedure
- Longitudinal study – 18 months
- Self-report data – interview and questionnaire every 6 months
- Asked about other drug users, legal sex trade, and criminality
- Daily dose of heroin injected
- HIV & Hepatitis tests
- Offered counselling
- Urine consistency checker – every 2 months – looking for traces of other drugs – checks reliability of data
Results
- Cocaine use fell form 84% to 48%
- Daily users of cocaine fell from 30% to 6%
- Non-cocaine users increased from 16% to 52%
- Illegal sources of income fell from 63% to 10%
- Positive correlation – 0.66 at in-take, 0.82 at 18 months – participants were telling the truth
Evaluation – generalisability
- Generalisable to other cultures – effects of drugs on the brain is the same – treatment should be the same
- Large sample of 266 makes it easier to generalise
- High percentage difference from start to end of study
- Representative of target population
- Can’t generalise to low drug users
- Gender bias towards men
- Switzerland is a culturally specific drugs scene
Ethics
- Had informed consent
- Approved by the National Ethics Committee
- Had right to withdraw – some dropped out original sample
- Study’s aim was in best interests of participants
- Competent
- Very costly
- Some may believe giving drugs is immoral
Reliability
- Reliable – triangulation – interview, questionnaire, urine sample
- Consistency checker increases reliability
- Reliability improved – positive correlation
Validity
- Large sample and reliable controls make it valid
- Results expected to go down – program to help them
- May have lied in questionnaires/interviews
- Some may have joined for free heroin with no intention of reducing cocaine use
- 48% were still taking cocaine at the end – not entirely successful
- Difficult to show and cause-effect relationships
Stacy et al 1993
Aim
- To investigate long term predictors of alcohol use and drinking related problems
- Look at the way drinking related problems link to personality factors including sensation seeking and cognitive motivation
- Investigate whether particular negative outcomes of drinking were related to particular reasons for drinking
Sample
- 64% white
- 71% female
- Mean age at start = 17.95 years
- Mean age at follow up = 26.95 years
- 11 junior high schools in LA – lower socioeconomic areas
Procedure
- Longitudinal study
- Participants being followed up as part of a wider investigation in to drug use
- Drop-out rate was very small and didn’t relate to drug use
- Self-report data – confidential questionnaires to provide measures of sensation seeking, cognitive motivation, and alcohol use at start and follow up
Sensation seeking
- Personality trait assumed to be at least partly genetic
- Linked to high risk behaviours
- 4 items rated on a likert scale – 1 (never) – 5 (always)
- Experience seeking
- Thrill and adventure seeking
- Disinhibition
- Boredom susceptibility
Cognitive motivation
- Reasons for someone’s behaviour
- Why they choose to drink alcohol based on their perceived consequences
- 4 scales of 3,4,5 items each
- Reduction of negative effect
- Enhancement of positive effect
- Social cohesion
- Addiction
Alcohol use
- At follow up, participants were asked 29 questions on problem-drinking consequences – identified personal, physical, social, and work related negative consequences of drinking – rated on a 3 point scale
- Asked about driving whilst intoxicated – measured frequency of response with arrest and conviction record
Results
- Cognitive motivation and alcohol use in adolescents both predicted problem-drinking consequences in adulthood
- Alcohol use predicted driving whilst intoxicated – especially beer and wine drinkers
- Cognitive factor of positive effect in adolescence also predicted driving whilst intoxicated
- Work related problems were predicted by thrill and adventure seeking and by social cohesion
- Link between adolescent personality and adult cognitive motivation
- Adolescents with higher sensation seeking scores grew to be adults with a greater cognitive motivation towards alcohol use
Evaluation
- Longitudinal study – no individual differences
- People may drop out – affects validity – study states few dropped out
Generalisability
- Sample representative of target population – lower socioeconomic groups
- Ethnocentric – only used in LA – may give different results to other areas
Reliability
- Good reliability – standardised procedure
- Could be replicated in other areas
Validity
- May be other social reasons e.g. social learning theory, that may also affect alcohol use
- Self-report data – may have given socially desirable answers – demand characteristics
- Confidential questionnaires – less likely to lie
- Likert scale limits responses
- Large sample helps it to be more representative and valid
Application to real life
- Can educate about behavioural types and alcohol related problems later in life
Ethics
- Informed consent
- Right to withdraw – some people dropped out
- Competence
- Confidential data