Gillian W. Smith

Patterns of polydrug use in Great Britain: Findings from a national household population survey

BACKGROUND Polydrug use potentially increases the likelihood of harm. As little is known about polydrug use patterns in the general population, it is difficult to determine patterns associated with highest likelihood. METHODS Latent class analysis was performed on nine illicit substance groups indicating past year use of cannabis, cocaine, amphetamines, ecstasy, LSD, mushrooms, amyl nitrate, tranquillisers and heroin or crack. Analyses were based on data from a large multi-stage probability sample of the population of Great Britain (n=8538) collected in 2000. Multinomial logistic regression was performed highlighting associations between classes, and demographic and mental health variables. RESULTS A three class solution best described patterns of polydrug use; wide range, moderate range, and no polydrug use. For males and young people, there was a significantly increased chance of being in the wide and moderate range polydrug use groups compared to the no polydrug use class. Hazardous drinking was more likely in the wide and moderate polydrug classes with odds ratios of 9.99 and 2.38 (respectively) compared to the no polydrug use class. Current smokers were more likely to be wide and moderate range polydrug users compared to the no polydrug use class with odds ratios of 4.53 and 5.85 respectively. A range of mental health variables were also related to class membership. CONCLUSIONS Polydrug use in Great Britain can be expressed as three distinct classes. Hazardous alcohol use and tobacco use were strongly associated with illicit polydrug use, polydrug use appeared to be significantly associated with mental health, particularly lifetime suicide attempts.

Patterns of Alcohol Consumption and Related Behaviour in Great Britain : A latent Class Analysis of the Alcohol Use Disorder Identification Test (AUDIT)

AIMS Attempts have been made to develop typologies to classify different types of alcoholism. However, limited research has focused on classifications to describe general patterns of alcohol use in general population samples. METHODS Latent class analysis was used to create empirically derived behaviour clusters of alcohol consumption and related problems from the Alcohol Use Disorder Identification Test (AUDIT) based on data from a large stratified multi-stage random sample of the population of Great Britain. Multinomial logistic regression was performed to describe these resultant classes using both demographic variables and mental health outcomes. RESULTS Six classes best described responses in the sample data. Three were heavy consumption groups, one with multiple negative consequences, one experiencing alcohol-related injury and social pressures to cut down and an additional class with memory loss. There was one moderate class with few negative consequences, and finally two mild consumption groups, one with alcohol-related injury and social pressure to cut down and one with no associated problems. CONCLUSIONS Alcohol use in Great Britain can be hypothesized as reflecting six distinct classes, four of which follow a continuum of increased consumption leading to increased dependence and related problems and two that do not. Differences between alcohol use classes are apparent with reduced risk of depressive episode in moderate classes and an increased risk of anxiety disorders for the highest consumers of alcohol.