Mental Health Issues: Drug Addiction

Vocabulary practice flashcards covering DSM-5-TR criteria, history, mesolimbic dopamine circuitry, neuroadaptations, conditioning models, and pharmacological/behavioral treatments for substance use disorders based on Lecture 4 and assigned readings.

Tolerance

A criterion of substance use disorder in DSM-5-TR defined by needing markedly increased amounts of the drug to achieve the desired effect or intoxication, or experiencing a diminished effect when using the same amount.

Withdrawal

A cluster of 'drug-opposite' physiological and psychological symptoms experienced when substance use is abruptly discontinued or reduced after heavy, prolonged administration (such as 'cold turkey' from opioids).

Theriac

An ancient compound medication based on 'mithridatum' (originally developed by Mithridates VI of Pontus) taken daily by Roman Emperor Marcus Aurelius; it contained opium and was prescribed by Galen to relieve anxiety and chest and stomach complaints.

Belinski (2016) Scythian Goldware

Rare 4th-century BC goldware unearthed from West Eurasian Steppe nomadic burial mounds, in which criminological analysis of interior black residues tested positive for both opium and cannabis.

Mesoaccumbens Dopamine Projection

The specific component of the mesolimbic dopamine system that originates in the ventral tegmental area (VTA) and projects forward to the nucleus accumbens, forming the critical neural pathway for reward and addiction.

Mesocortical Dopamine Projection

The dopaminergic pathway originating in the ventral tegmental area (VTA) and projecting directly to the medial prefrontal cortex.

Medial Forebrain Bundle (mfb)

A major tract of ascending and descending axonal fibers traversing the lateral hypothalamus that includes the mesoaccumbens dopamine projection from the VTA to the nucleus accumbens.

Intra-Cranial Self-Stimulation (ICSS)

An operant procedure discovered by Olds and Milner (1954) in which subjects press a lever to deliver reinforcing electrical sine-wave current directly to specific brain regions, such as the medial forebrain bundle.

Olds (1958) Cumulative ICSS Tracing

A cumulative chart recorder tracing demonstrating that rats permitted to self-stimulate the medial forebrain bundle pressed the lever at relentless, near-vertical rates for $24\,\text{hours}$ continuously with virtually no pauses until physical exhaustion intervened.

Bishop et al. (1963)

A clinical study demonstrating the power of intracranial self-stimulation in humans, where a participant continued self-stimulating brain reward centers without interruption, ignoring an attractive food tray despite having been food-deprived for $7\,\text{hours}$.

Striatal D2 Receptor Downregulation

A homeostatic neuroadaptation characterized by a significant reduction in available dopamine D2 receptors in the striatum and nucleus accumbens following chronic exposure to drugs such as cocaine, amphetamines, or nicotine.

Franklin et al. (2002)

A neuroimaging study demonstrating significant reductions in frontal grey matter volume (neuronal cell bodies) in crack cocaine addicts who had used the drug for an average duration of $13\,\text{years}$.

Thompson et al. (2004) Methamphetamine Brain Map

A neuroimaging reconstruction showing widespread grey matter volume reduction in chronic methamphetamine users across the cingulate gyrus, subgenual cortex, paralimbic belts around the corpus callosum, and hippocampus.

Incentive-Sensitization Theory

A model formulated by Robinson and Berridge positing that addictive drugs sensitize the mesoaccumbens dopamine projection, causing drug-associated conditioned stimuli (CS) to acquire potent motivational salience and trigger persistent craving and relapse.

Pavlovian Drug Conditioning

The learning process wherein initially neutral cues (CS, such as drug paraphernalia or environments) are repeatedly paired with drug delivery (US), causing the CS alone to elicit dopamine release, subjective craving, and conditioned responses.

Antabuse (Disulfiram)

A pharmacological deterrent for alcohol use disorder that remains inert until alcohol is ingested, upon which it inhibits acetaldehyde breakdown and causes severe physiological illness, including nausea, flushing, and vomiting.

Methadone

A long-acting, mild synthetic opioid agonist prescribed in opioid use disorder to occupy opioid receptors, suppress withdrawal symptoms and craving, and prevent the euphoric high of heroin.

TA-CD (Cocaine Vaccine)

An experimental immunological treatment evaluated by Martell et al. (2005) that stimulates the immune system to produce cocaine-specific antibodies, sequestering the drug in the bloodstream to prevent it from crossing the blood-brain barrier.

Extinction Therapy

A psychological intervention in which addicts are repeatedly exposed to drug-associated cues without drug administration to extinguish conditioned craving; its clinical utility is constrained by marked context specificity.

Delta-9-Tetrahydrocannabinol (Delta-9-THC)

The primary psychoactive cannabinoid found in Cannabis sativa that binds to CB1 receptors and is responsible for producing the intoxicating 'high.'

CB1 Receptor

The cannabinoid receptor expressed widely across the central nervous system, with especially high density in the hippocampus, linking cannabis consumption to memory and cognitive impairments.

Three Waves of the Opioid Crisis

The epidemiological progression of American opioid overdose mortality: Wave 1 (beginning in the 1990s) driven by prescription pain pills, Wave 2 (beginning in 2010) driven by heroin, and Wave 3 (beginning in 2013) driven by illicit synthetic opioids such as fentanyl.

Tweaking

The crash phase of methamphetamine intoxication following the high and shoulder phases, during which the user experiences intense agitation, irritability, and severe dysphoria.

Hallucinogen Persisting Perception Disorder (HPPD)

A DSM-5-TR diagnostic category defined by spontaneous, disturbing recurrences of perceptual distortions or flashbacks originally experienced during hallucinogen intoxication, occurring long after drug cessation.

MDMA (Ecstasy)

A synthetic substance containing chemical properties of both amphetamines and hallucinogens that primarily causes the release and reuptake blockade of serotonin, enhancing empathy, interpersonal insight, and emotional intimacy.