Substance use disorder

What is Substance Use Disorder?

A treatable health condition where an individual compulsively uses substances or engages in behaviors despite harmful consequences. It involves brain changes (psychological and physical) and has genetic, neural, environmental, and social causes.

How is addiction severity measured in DSM-5?

The lower the total criteria number, the less severe the addiction. DSM-5 is more commonly used in the US than in other countries.

How does the route of drug administration affect euphoria?

The quicker and stronger the drug gets to the system, the larger the euphoric effect. Injecting, snorting, or rubbing on the gums can cause high euphoric effects.

What happens during the addiction cycle regarding withdrawal?

• Over time, repeated use reinforces the addiction cycle.

• Withdrawal symptoms (physical and psychological) drive individuals to continue taking the drug to avoid these symptoms.

• Physical symptoms worsen over time, leading to anticipation and continued use

How does tolerance develop in addiction?

Dopamine receptors become less sensitive with repeated use, so more drug is needed to achieve the same pleasurable effect.

This is due to a greater rate of endocytosis, leading to fewer receptors on the plasma membrane.

What are the genetic and social aspects of addiction?

Addiction has both genetic and social components. Environmental cues (e.g., specific places or people) can trigger cravings, making it hard to overcome addiction without removing these cues.

How does alcohol affect GABA_A receptors?

Alcohol changes the subunit composition of GABA_A receptors, causing them to function less effectively. This leads to a decrease in inhibitory signaling and contributes to the development of tolerance and dependence.

What are functional alcoholics?

Individuals who consume enough alcohol to keep withdrawal symptoms at bay but are still able to maintain a job and daily responsibilities.

How does disulfiram work in treating AUD?

Disulfiram prevents the breakdown of alcohol, leading to a build-up of acetaldehyde, which causes nausea. Adherence is poor because patients are aware of the negative effects.

What is the mechanism of acamprosate in treating AUD?

Acamprosate partially mimics the effects of alcohol but in a mild way, limiting glutamatergic activity. Adherence is poor due to the need for 2 tablets 3 times a day.

How does naltrexone reduce alcohol consumption?

Naltrexone is a mu opioid receptor antagonist that blocks the effect of ethanol-induced beta-endorphin release, reducing the positive feeling associated with alcohol consumption.

Why are benzodiazepines used for alcohol withdrawal?

Benzodiazepines work through GABA_A receptors, similar to alcohol, and are effective in managing acute withdrawal symptoms, preventing agitation, seizures, and delirium tremens.

What are the roles of the mesolimbic and nigrostriatal pathways in addiction?

• Mesolimbic Pathway: Motivational pull towards cues and rewards.

• Nigrostriatal Pathway: Push towards invigorating or arousing behaviors.

What are cue-induced cravings in addiction?

Cravings triggered by environmental cues (e.g., specific places, people, or situations) associated with drug use. Overcoming these cravings often requires removing oneself from these cues.

How does alcohol affect beta-endorphin release?

Alcohol increases beta-endorphin release, which is an endogenous opioid. This leads to opioid-like effects, contributing to the pleasurable feelings associated with alcohol consumption.