Cannabis and Alcohol Use and Development of Mental Disorders
Purpose of Review: The purpose of this review was to examine recent evidence on the possible associations between cannabis and alcohol misuse and the development of mental disorders, particularly among young people.
Recent Findings: The authors concluded that although a wide body of research has demonstrated the existence of such associations, the natures of the relationships involved are highly complex in character, and in all probability involve the mediation of a variety of additional factors. It is surmised that many of these additional factors relate to the experience of social exclusion.
Summary: The authors call for further research to be carried out to extend existing knowledge of the nature of these associations and the way in which the experience of social exclusion impact upon them. Such research should be UK specific, population based and longitudinal in nature, and have at its heart an understanding of the nature of social exclusion and the bearing it has on both the misuse of substances and the risk of developing mental disorders.
This review examines what is known of the relationship between cannabis use, alcohol use and the development of various mental disorders. We provide an overview of the key factors that relate to this issue, and examine the more pertinent recent research currently contributing to the debate surrounding substance misuse and its linkages with developing mental disorder, particularly in younger people.
We conclude that there is wide body of research that has demonstrated the existence of a variety of associations between substance misuse and the development of mental disorders. These relationships are complex, and in all probability involve the mediation of a variety of additional factors. Later, we review the methodological issues that affect the nature of the association. A supplementary remit of our review is to explore briefly how discussions around the multifaceted issue of social exclusion may relate to research on links between substance misuse and mental disorder.
Not all of the research that we summarize in this review has been carried out on children or adolescents. However, we attempt to relate research on other populations to the potential impact that its findings have for younger people.
Our emphasis on young people is particularly important for a number of reasons, the most striking of which is the markedly higher prevalence of substance use by young people than has been noted in the past. For example, the British Crime Survey (2001-2002) reported that people aged between 16 and 24 years are significantly more likely to have used drugs in the past year and the past month than older people. Second, much of the attention given by the media and policymakers to the recent growth of substance misuse relates in particular to fears about its possible impact on the lives of younger people and the communities in which they live. A vast array of research has demonstrated that the range of those impacts is wide. The list includes: adverse effects such as psychiatric problems; the risk of suicide; high-risk sexual behaviours leading to higher rates of unwanted pregnancies and of sexually transmitted disease; homelessness; a high risk of fatal and non-fatal injuries and accidents, violence, homicides and delinquency; and contact with the criminal justice system and related high healthcare costs. Third, research also suggests that the prevalence of substance use in adolescence increases sharply with age, with only 6% of 11 year olds reportedly using drugs compared with 39% of 15 year olds. A UK-based study found that the regular monthly usage of alcohol rose from 5.1% at the age of 11 years to 36% at 16 years.
Although the furore surrounding adolescent use of substances seemingly concentrates on the 'use' or 'misuse' of illicit drugs, within the UK, alcohol use and misuse may be far more problematical for this age group.
'The UK figures for alcohol consumption among 15-16 year olds are some of the highest in Europe, along with Ireland and Denmark. Ninety-four per cent of 15-16 year olds have consumed alcohol at least once, with 47 per cent having drunk alcohol at least 40 times, compared with 20 per cent of 15-16 year olds in France and 15 per cent of this age group in Portugal'.
A number of studies have noted that alcohol and tobacco are the most frequently used substances, and that, therefore, it is these that account for the vast majority of drug-related morbidity and mortality.
Many authors regard the early onset of use of both cannabis and alcohol as particularly problematical, as there is a deal of evidence to suggest that early onset is associated with the increased risk of severely problematical future use and with the increased risk of developing mental disorder. There are reports from the UK that up to 60% of boys and 40% of girls aged 11-12 years have tried at least one alcoholic drink, with 9% of boys and 5% of girls describing themselves as regular drinkers. Among 11-15 year olds in England in 2001, 12% had used drugs in the past month and 20% had used drugs in the past year. Cannabis is reported to be the most frequently used illicit drug (13% reported use in the past year).
For the purposes of this review, we distinguish between substance 'use' and substance 'misuse'. Broadly speaking, 'use' is experimental and recreational use and 'misuse' is that relating to the more problematical and damaging use of substances. Not all of the literature pertaining to this issue makes this distinction; some portray any use of drugs that are not intended to be medicinal or that are unlawfully obtained as 'abuse'. However, maintenance of the division between the terms is necessary as the term 'abuse', when used uncritically, blurs the distinction necessary for clarity among clinicians and researchers. Nonetheless, defining what constitutes 'use' or 'misuse' is a complex matter, the precise meaning of which may vary between substances and across different age groups.
In addition to the anxiety surrounding the increased and earlier usage of substances by young people, the possible secondary consequences of substance use have gained heightened policy and media attention. Drug-related deaths, drug-related crime and, the main issue of this review, links with mental disorder, have generated a plethora of recent research and media attention. However, it is to the last issue of co-morbidity to which we turn now in some detail.
Purpose of Review: The purpose of this review was to examine recent evidence on the possible associations between cannabis and alcohol misuse and the development of mental disorders, particularly among young people.
Recent Findings: The authors concluded that although a wide body of research has demonstrated the existence of such associations, the natures of the relationships involved are highly complex in character, and in all probability involve the mediation of a variety of additional factors. It is surmised that many of these additional factors relate to the experience of social exclusion.
Summary: The authors call for further research to be carried out to extend existing knowledge of the nature of these associations and the way in which the experience of social exclusion impact upon them. Such research should be UK specific, population based and longitudinal in nature, and have at its heart an understanding of the nature of social exclusion and the bearing it has on both the misuse of substances and the risk of developing mental disorders.
This review examines what is known of the relationship between cannabis use, alcohol use and the development of various mental disorders. We provide an overview of the key factors that relate to this issue, and examine the more pertinent recent research currently contributing to the debate surrounding substance misuse and its linkages with developing mental disorder, particularly in younger people.
We conclude that there is wide body of research that has demonstrated the existence of a variety of associations between substance misuse and the development of mental disorders. These relationships are complex, and in all probability involve the mediation of a variety of additional factors. Later, we review the methodological issues that affect the nature of the association. A supplementary remit of our review is to explore briefly how discussions around the multifaceted issue of social exclusion may relate to research on links between substance misuse and mental disorder.
Not all of the research that we summarize in this review has been carried out on children or adolescents. However, we attempt to relate research on other populations to the potential impact that its findings have for younger people.
Our emphasis on young people is particularly important for a number of reasons, the most striking of which is the markedly higher prevalence of substance use by young people than has been noted in the past. For example, the British Crime Survey (2001-2002) reported that people aged between 16 and 24 years are significantly more likely to have used drugs in the past year and the past month than older people. Second, much of the attention given by the media and policymakers to the recent growth of substance misuse relates in particular to fears about its possible impact on the lives of younger people and the communities in which they live. A vast array of research has demonstrated that the range of those impacts is wide. The list includes: adverse effects such as psychiatric problems; the risk of suicide; high-risk sexual behaviours leading to higher rates of unwanted pregnancies and of sexually transmitted disease; homelessness; a high risk of fatal and non-fatal injuries and accidents, violence, homicides and delinquency; and contact with the criminal justice system and related high healthcare costs. Third, research also suggests that the prevalence of substance use in adolescence increases sharply with age, with only 6% of 11 year olds reportedly using drugs compared with 39% of 15 year olds. A UK-based study found that the regular monthly usage of alcohol rose from 5.1% at the age of 11 years to 36% at 16 years.
Although the furore surrounding adolescent use of substances seemingly concentrates on the 'use' or 'misuse' of illicit drugs, within the UK, alcohol use and misuse may be far more problematical for this age group.
'The UK figures for alcohol consumption among 15-16 year olds are some of the highest in Europe, along with Ireland and Denmark. Ninety-four per cent of 15-16 year olds have consumed alcohol at least once, with 47 per cent having drunk alcohol at least 40 times, compared with 20 per cent of 15-16 year olds in France and 15 per cent of this age group in Portugal'.
A number of studies have noted that alcohol and tobacco are the most frequently used substances, and that, therefore, it is these that account for the vast majority of drug-related morbidity and mortality.
Many authors regard the early onset of use of both cannabis and alcohol as particularly problematical, as there is a deal of evidence to suggest that early onset is associated with the increased risk of severely problematical future use and with the increased risk of developing mental disorder. There are reports from the UK that up to 60% of boys and 40% of girls aged 11-12 years have tried at least one alcoholic drink, with 9% of boys and 5% of girls describing themselves as regular drinkers. Among 11-15 year olds in England in 2001, 12% had used drugs in the past month and 20% had used drugs in the past year. Cannabis is reported to be the most frequently used illicit drug (13% reported use in the past year).
For the purposes of this review, we distinguish between substance 'use' and substance 'misuse'. Broadly speaking, 'use' is experimental and recreational use and 'misuse' is that relating to the more problematical and damaging use of substances. Not all of the literature pertaining to this issue makes this distinction; some portray any use of drugs that are not intended to be medicinal or that are unlawfully obtained as 'abuse'. However, maintenance of the division between the terms is necessary as the term 'abuse', when used uncritically, blurs the distinction necessary for clarity among clinicians and researchers. Nonetheless, defining what constitutes 'use' or 'misuse' is a complex matter, the precise meaning of which may vary between substances and across different age groups.
In addition to the anxiety surrounding the increased and earlier usage of substances by young people, the possible secondary consequences of substance use have gained heightened policy and media attention. Drug-related deaths, drug-related crime and, the main issue of this review, links with mental disorder, have generated a plethora of recent research and media attention. However, it is to the last issue of co-morbidity to which we turn now in some detail.