Addiction and dependence glossary[1][2][3] | |
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Psychological dependence is a cognitive disorder and a form of dependence that is characterized by emotional–motivational withdrawal symptoms upon cessation of prolonged drug use or certain repetitive behaviors.[4] Consistent and frequent exposure to particular substances or behaviors is responsible for inducing psychological dependence, requiring ongoing engagement to prevent the onset of an unpleasant withdrawal syndrome driven by negative reinforcement.[5][6] Neuronal counter-adaptation is believed to contribute to the generation of withdrawal symptoms through changes in neurotransmitter activity or altered receptor expression.[5][6][7] Environmental enrichment and physical activity have been shown to attenuate withdrawal symptoms.[6]
Despite the importance of numerous psychosocial factors, at its core, drug addiction involves a biological process: the ability of repeated exposure to a drug of abuse to induce changes in a vulnerable brain that drive the compulsive seeking and taking of drugs, and loss of control over drug use, that define a state of addiction. ... A large body of literature has demonstrated that such ΔFosB induction in D1-type [nucleus accumbens] neurons increases an animal's sensitivity to drug as well as natural rewards and promotes drug self-administration, presumably through a process of positive reinforcement ... Another ΔFosB target is cFos: as ΔFosB accumulates with repeated drug exposure it represses c-Fos and contributes to the molecular switch whereby ΔFosB is selectively induced in the chronic drug-treated state.41. ... Moreover, there is increasing evidence that, despite a range of genetic risks for addiction across the population, exposure to sufficiently high doses of a drug for long periods of time can transform someone who has relatively lower genetic loading into an addict.
Substance-use disorder: A diagnostic term in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) referring to recurrent use of alcohol or other drugs that causes clinically and functionally significant impairment, such as health problems, disability, and failure to meet major responsibilities at work, school, or home. Depending on the level of severity, this disorder is classified as mild, moderate, or severe.
Addiction: A term used to indicate the most severe, chronic stage of substance-use disorder, in which there is a substantial loss of self-control, as indicated by compulsive drug taking despite the desire to stop taking the drug. In the DSM-5, the term addiction is synonymous with the classification of severe substance-use disorder.
Dependence is defined as an adaptive state that develops in response to repeated drug administration, and is unmasked during withdrawal, which occurs when drug taking stops. Dependence resulting from long-term drug use may have both a somatic component, manifested by physical symptoms, and an emotional–motivational component, manifested by dysphoria and anhedonic symptoms, that occur when a drug is discontinued. While physical dependence and withdrawal occur dramatically with some drugs of abuse (opiates, ethanol), these phenomena are not useful in the diagnosis of an addiction because they do not occur as robustly with other drugs of abuse (cocaine, amphetamine) and can occur with many drugs that are not abused (propranolol, clonidine). The official diagnosis of drug addiction by the Diagnostic and Statistical Manual of Mental Disorders (2013), which uses the term substance use disorder, is flawed. Criteria used to make the diagnosis of substance use disorders include tolerance and somatic dependence/withdrawal, even though these processes are not integral to addiction as noted. ...
As previously discussed, cessation of cocaine use and the use of other psychostimulants in dependent individuals does not produce a physical withdrawal syndrome but may produce dysphoria, anhedonia, and an intense desire to reinitiate drug use. ...
Long-term caffeine use can lead to mild physical dependence.
Stimulant and opiate drugs of abuse activate CREB in several brain regions important for addiction, including prominently in the NAc. ...
Drug activation of CREB in NAc has been shown to represent a classic negative feedback mechanism, whereby CREB serves to reduce an animal's sensitivity to the rewarding effects of these drugs (tolerance) and to mediate a negative emotional state during drug withdrawal (dependence). These effects have been shown recently to drive increased drug self-administration and relapse, presumably through a process of negative reinforcement.
Natural and drug addictions
was invoked but never defined (see the help page).