Hallucinogens attach to serotonin ____ __ receptors and provide stimulation at inappropriate times or for longer than usual durations.
The drug ___________ (MDMA, or "ecstasy"), is a stimulant at low doses, increasing the release of dopamine and producing effects similar to amphetamine or cocaine.
At higher doses, MDMA also releases serotonin, altering ____ and ____ like hallucinogenic drugs.
perception and cognition
Many people use MDMA at dance parties to increase their energy levels and pleasure. However, after the effects wear off, users experience ____ and ____.
lethargy and depression
In moderate amounts ____ relaxes people and decreases anxiety.
In larger amounts, alcohol causes ____ ____, ____ ____, and ruins lives.
health problems, impairs judgement
____ or alcohol dependence is the habitual use of alcohol despite medical or social harm.
Alcohol facilitates response at the GABA receptor, the brains main inhibitory site. It also blocks activity at the glutamate receptors, the brain's main excitatory site. Both the GABA effect and glutamate effect lead to a decrease in ____ ____.
Studies of twins and adoptees confirm a strong influence of ____ on vulnerability to alcoholism.
People with ______ alcoholism develop alcohol problems gradually, usually after age 25, and may or may not have relatives with alcohol abuse.
Type 1 (or Type A)
Those with ______ alcoholism have more rapid onset, usually before age 25. Most are men, and most have close relatives with alcohol problems.
Type 2 (or Type B)
One identified gene in alcoholism controls variations of the _____ ____ receptor, one of the five known types of dopamine receptor.
dopamine type 4
The dopamine type 4 receptor has two common forms, short and long. The ____ ____ is less sensitive, and people with the long form report stronger than average cravings for additional alcohol after having one drink.
Another key gene in alcoholism controls COMT, an ____ that breaks down dopamine after its release. Some people have a less active form of this ____ and others have a more active form.
The more active form of the COMT enzyme breaks down more dopamine and therefore ____ ____ People with that gene tend to be more impulsive – to choose immediate reward instead of bigger rewards later.
____ ____ also contributes to the risk for alcoholism.
Nearly everyone was an addiction recognises that the habit does more harm than good. As the addiction progresses, the pleasure becomes ____ while the costs and risks ____. And yet the person remains preoccupied, unable to quit.
weaker : increase
As an addiction develops, many of its effects, especially the enjoyable effects, decrease. That decrease is called ____.
The effects of drug cessation are called ____. As the body comes to expect the drug, it reacts strongly when the drug is absent.
Explanations of addiction 1. One explanation that theorists have advanced to explain addiction is that it is an attempt to avoid ____ ____.
Explanations of addiction 2. A modified explanation is that someone with an addiction learns to use the substance to ____ ____ ____.
cope with stress
Explanations of addiction 3. Another hypothesis is that a drug user learns to associate cues with a drug. Later, even after a long period of abstinence, exposure to those cues triggers a ____ ____.
Although escape from withdrawal symptoms and conditioned responses to cues are important, they seem insufficient to explain the way in addiction completely ____ someone's life.
Somehow, the addiction hijacks the persons motivations. It changes the ____ so that other kinds of reinforcing experiences become less powerful, less able to compete with the drug.
After some drinks ethyl alcohol, enzymes in the liver metabolise it to ____, a poisonous substance. An enzyme, ____ dehydrogenase, then converts ____ to acetic acid, a chemical that the body uses for energy.
People with a weaker gene for acetaldehyde dehydrogenase metabolise acetaldehyde more ____.
If one drinks too much alcohol, they accumulate acetaldehyde, which produces ____ of the face, increased ____ rate, ____, ____, ____ pain, impaired ____, and ____ damage.
flushing, heart, nausea, headache, abdominal, breathing, tissue
The drug disulfiram, which goes by the trade name ____, antagonises the effects of acetaldehyde dehydrogenase by binding to its copper ion. The effect is becoming sick when drinking alcohol.
____ is an artificial substance invented in the 1800s as a supposedly safer alternative for people who were trying to quit morphine.
____ is similar to heroine and morphine but has the advantage that can be taken orally.
Methadone taken orally gradually enters the blood and then the brain, so its effects rise slowly, avoiding the rush experience. Because it is ____ slowly, the withdrawal symptoms are also gradual.