Substance use disorders and other addictions – Course, natural history and prognosis

Addiction is a chronic brain disease, with potential outcomes ranging from relapse (a return to substance use) to remission (regaining health and social function).^[1] Moreover, addiction is a widespread condition across the globe; healthcare providers, policymakers,…

The degree to which tolerance to a substance can develop over time differs between individuals, and between different substances.^[5] It is difficult to determine whether and to what degree tolerance to a substance may have occurred.^[

Addiction is a chronic brain disease.^[2] It is increasingly recognized that a person with addiction undergoes brain changes as they move through the addiction cycle of binge and intoxication, withdrawal and negative affect, and finally preoccupation…

Although the situation and the reasons vary, substance dependence and addiction involve a transition from casual, impulsive drug use to compulsive drug use.^[1] Compulsion is characterized by repetition of a behaviour despite the adverse consequences of…

Brain changes occur as the addiction cycle progresses.^[3] Changes occur in the forebrain, including in the extended amygdala, involving many different neurotransmitter systems, that result in increased vulnerability to cravings and preoccupations in order to counter…

During the preoccupation and anticipation stage, environmental cues associated with the addictive substance elicit a strong dopamine response from the dysregulated reward and motivation circuitry within the brain.^[3] Furthermore, in the case of many individuals with…

The diagram on the slide illustrates the interaction between neurocircuitry and behaviour of addiction, divided into binge/intoxication, withdrawal/negative affect, and preoccupation/anticipation, each of which is associated with the activation of certain neurological pathways.

Three areas of the brain are particularly…

The possibility that cigarette smoking acts as a priming agent for substance use later in life,^[3,4,2] or that there are common liabilities to nicotine and other addictions,^[

As outlined on the slide, some researchers have used Mendelian randomization techniques to study the gateway hypothesis, particularly relating to cigarettes and e-cigarette smoking.^[1,2] In the study on the slide, a two-sample…

The slide summarises some of the pioneering work done into the possible molecular and genetic factors underlying the potential role of nicotine (and therefore cigarette smoking) as a agent that may lower the threshold for addiction to other agents.^[

Across the world, the approach to regulation of e-cigarettes varies from a total focus on health protection (meaning policies to prevent the harms of e-cigarettes), to a focus on the benefits of e-cigarettes on harm prevention (meaning policies to promote…

The gateway hypothesis and the idea of common underlying liability represent two competing models to explain the relationship that is observed between different addictions and addictive behaviours.^[1] Within the former model, initial substance use acts as…

The study on the slide calculated polygenic risk scores (PRS) from a large UK dataset, and used logistic regression analysis to assess whether the association between self-reported smoking initiation and e-cigarette use could be explained by the PRS for smoking…