Popular intoxicants: what lessons can be learned from the last 40 years of alcohol and cannabis regulation?

The Classification of Substance Use Disorders: Historical, Contextual, and Conceptual Considerations

This article provides an overview of the history of substance use and misuse and chronicles the long shared history humans have had with psychoactive substances, including alcohol. The practical and personal functions of substances and the prevailing views of society towards substance users are described for selected historical periods and within certain cultural contexts. This article portrays how the changing historical and cultural milieu influences the prevailing medical, moral, and legal conceptualizations of substance use as reflected both in popular opinion and the consensus of the scientific community and represented by the American Psychiatric Association’s (APA) Diagnostic and Statistical Manual of Mental Disorders (DSM). Finally, this article discusses the efforts to classify substance use disorders (SUDs) and associated psychopathology in the APA compendium. Controversies both lingering and resolved in the field are discussed, and implications for the future of SUD diagnoses are identified.

Persistent cannabis dependence and alcohol dependence represent risks for midlife economic and social problems: A longitudinal cohort study

With the increasing legalization of cannabis, understanding the consequences of cannabis use is particularly timely. We examined the association between cannabis use and dependence, prospectively assessed between ages 18-38, and economic and social problems at age 38. We studied participants in the Dunedin Longitudinal Study, a cohort (n=1,037) followed from birth to age 38. Study members with regular cannabis use and persistent dependence experienced downward socioeconomic mobility, more financial difficulties, workplace problems, and relationship conflict in early midlife. Cannabis dependence was not linked to traffic-related convictions. Associations were not explained by socioeconomic adversity, childhood psychopathology, achievement orientation, or family structure; cannabis-related criminal convictions; early onset of cannabis dependence; or comorbid substance dependence. Cannabis dependence was associated with more financial difficulties than alcohol dependence; no difference was found in risks for other economic or social problems. Cannabis dependence is not associated with fewer harmful economic and social problems than alcohol dependence.

Mechanisms of Action and Persistent Neuroplasticity by Drugs of Abuse

Adaptation of the nervous system to different chemical and physiologic conditions is important for the homeostasis of brain processes and for learning and remembering appropriate responses to challenges. Although processes such as tolerance and dependence to various drugs of abuse have been known for a long time, it was recently discovered that even a single pharmacologically relevant dose of various drugs of abuse induces neuroplasticity in selected neuronal populations, such as the dopamine neurons of the ventral tegmental area, which persist long after the drug has been excreted. Prolonged (self-) administration of drugs induces gene expression, neurochemical, neurophysiological, and structural changes in many brain cell populations. These region-specific changes correlate with addiction, drug intake, and conditioned drugs effects, such as cue- or stress-induced reinstatement of drug seeking. In rodents, adolescent drug exposure often causes significantly more behavioral changes later in adulthood than a corresponding exposure in adults. Clinically the most impairing and devastating effects on the brain are produced by alcohol during fetal development. In adult recreational drug users or in medicated patients, it has been difficult to find persistent functional or behavioral changes, suggesting that heavy exposure to drugs of abuse is needed for neurotoxicity and for persistent emotional and cognitive alterations. This review describes recent advances in this important area of research, which harbors the aim of translating this knowledge to better treatments for addictions and related neuropsychiatric illnesses.

Cannabis psychosis, gender matters

Purpose

– The purpose of this paper is to draw together key literature and analyses of data on admissions for cannabis psychosis in National Health Service hospitals in England (extracted from Hospital Episode Statistics (HES)) to highlight what is known about gender differences in cannabis psychosis and point towards suggestions for improving gender-sensitive treatment and future research.

Design/methodology/approach

– Analysis of British Crime Survey data and HES data were used in combination with data from previously published epidemiological studies to compare gender differences.

Findings

– Male cannabis users outnumber female users by 2:1, a similar gender ratio is found for those admitted to hospital with a diagnosis of schizophrenia or psychosis. However this ratio increases significantly for those admitted to hospital with a diagnosis of cannabis psychosis, with males outnumbering females by 4:1.

Research limitations/implications

– Consistent patterns in gender ratios for people admitted to hospital with cannabis psychosis over a period of 11 years are reported, it is not clear why this gender difference persists but it warrants further investigation which would be aided by improved gender recording at a systemic level.

Practical implications

– This review brings into focus the marked gender differences in cannabis psychosis. Attending to gender is important for research and treatment with the aim of improving understanding and providing gender-sensitive services.

Originality/value

– This paper adds to the literature on gender differences in cannabis psychosis.

Effect of reclassification of cannabis on hospital admissions for cannabis psychosis: a time series analysis

BACKGROUND

The UK Misuse of Drugs Act (1971) divided controlled drugs into three groups A, B and C, with descending criminal sanctions attached to each class. Cannabis was originally assigned by the Act to Group B but in 2004, it was transferred to the lowest risk group, Group C. Then in 2009, on the basis of increasing concerns about a link between high strength cannabis and schizophrenia, it was moved back to Group B. The aim of this study is to test the assumption that changes in classification lead to changes in levels of psychosis. In particular, it explores whether the two changes in 2004 and 2009 were associated with changes in the numbers of people admitted for cannabis psychosis.

METHOD

An interrupted time series was used to investigate the relationship between the two changes in cannabis classification and their impact on hospital admissions for cannabis psychosis. Reflecting the two policy changes, two interruptions to the time series were made. Hospital Episode Statistics admissions data was analysed covering the period 1999 through to 2010.

RESULTS

There was a significantly increasing trend in cannabis psychosis admissions from 1999 to 2004. However, following the reclassification of cannabis from B to C in 2004, there was a significant change in the trend such that cannabis psychosis admissions declined to 2009. Following the second reclassification of cannabis back to class B in 2009, there was a significant change to increasing admissions.

CONCLUSION

This study shows a statistical association between the reclassification of cannabis and hospital admissions for cannabis psychosis in the opposite direction to that predicted by the presumed relationship between the two. However, the reasons for this statistical association are unclear. It is unlikely to be due to changes in cannabis use over this period. Other possible explanations include changes in policing and systemic changes in mental health services unrelated to classification decisions.

Effects of Schedule I drug laws on neuroscience research and treatment innovation

Many psychoactive drugs are used recreationally, particularly by young people. This use and its perceived dangers have led to many different classes of drugs being banned under national laws and international conventions. Indeed, the possession of cannabis, 3,4-methylenedioxy-N-methylamphetamine (MDMA; also known as ecstasy) and psychedelics is stringently regulated. An important and unfortunate outcome of the controls placed on these and other psychoactive drugs is that they make research into their mechanisms of action and potential therapeutic uses - for example, in depression and post-traumatic stress disorder - difficult and in many cases almost impossible.