The Psychology Behind Addiction

1. The Psychology Behind Addiction By: Chase Oesch

2. Tolerance: • A drug’s effects can also change as the person’s body develops a tolerance to the chemical • Tolerance refers to a progressive decrease in a person’s responsive to a drug as a result of continued use. • Tolerance usually leads people to consume larger and larger doses of a drug to attain the effects they desire.

3. Neurotransmitters • Most drugs have effects that reverberate throughout the body. However, psychoactive drugs work primarily by altering neurotransmitter reactivity in the brain. • Neurotransmitters are chemicals that transmit signals between neurons at junctions called synapse

4. “Reward Pathway” • The “reward pathway” in the brain. The neural circuits shown here in blue make up the mesolimbic dopamine pathway. • Axons in this pathway run from an area in the midbrain through the medial forebrain bundle to the nucleus accubens and on to the prefrontal cortex. • Recreational drugs affect a variety of neurotransmitter system, but theorists believe that heightened dopamine activity in this pathway- especially the portion running from the midbrain to the nucleus accumbens-is responsible for the reinforcing effects of most abused drugs.

5. Physical Dependence • Physical dependence exists when a person must continue to take a drug to avoid withdrawal illness. The symptoms of withdrawal illness depend on the specific drugs. • Withdrawal from heroin, barbiturates, and alcohol can produce fever, chills, tremors, convulsions, vomiting, cramps, diarrhea, and severe aches and pains. • Withdrawal from stimulants leads to more subtle syndrome, marked by fatigue, apathy, irritability, depression, and disorientation.

6. Psychological Dependence • Psychological dependence exists when a person must continue to take a drug to satisfy intense mental and emotional craving. • Psychological dependence is more subtle than physical dependence, but the need it creates can be powerful. • Cocaine, for instance, can produce an overwhelming psychological need for continue use. Psychological dependence is possible with all recreational drugs, although it seems rare for hallucinogens.

7. Drugs Vary • Drugs vary in their potential for creating either physical or psychological dependence.

8. A Few Drugs with Some Symptoms • Heroin causes a “rush” of pleasure in the user that is usually followed by several hours of drowsiness. It is very addictive and causes withdrawal constantly. • Alcohol causes drowsiness, misjudgment, loss of motor coordination, impairs reasoning, balance, speech, and reaction time.

9. What Part of the Brain causes Drowsiness? • Neurons in the brainstem, which connects the brain with the spinal cord, produce neurotransmitters such as serotonin and norepinephrine that keep some parts of the brain active while we are awake. • Other neurons at the base of the brain begin signaling when we fall asleep. These neurons appear to "switch off" the signals that keep us awake. • Research also suggests that a chemical called adenosine builds up in our blood while we are awake and causes drowsiness. This chemical gradually breaks down while we sleep.

10. How do drugs work in the brain to produce pleasure? • Most drugs of abuse directly or indirectly target the brain's reward system by flooding the circuit with dopamine. • Dopamine is a neurotransmitter present in regions of the brain that regulate movement, emotion, cognition, motivation, and feelings of pleasure. • The overstimulation of this system, which rewards our natural behaviors, produces the euphoric effects sought by people who abuse drugs and teaches them to repeat the behavior.

11. Why are drugs more addictive than natural rewards? • When some drugs of abuse are taken, they can release 2 to 10 times the amount of dopamine that natural rewards do. • In some cases, this occurs almost immediately (as when drugs are smoked or injected), and the effects can last much longer than those produced by natural rewards. • The resulting effects on the brain's pleasure circuit dwarfs those produced by naturally rewarding behaviors such as eating and sex. • The effect of such a powerful reward strongly motivates people to take drugs again and again. This is why scientists sometimes say that drug abuse is something we learn to do very, very well.

12. Example of a “Reward Pathway” • Let’s take a closer look at how the reward pathway works. Imagine you haven’t eaten all day and someone gives you a nice big sandwich. Your five senses gather information from your surroundings and send signals to the brain letting it know that there is a yummy looking sandwich in front of you. • Stored in another part of your brain is the memory that when you eat a sandwich, you will no longer be hungry and you will feel good. Based on this information, the brain tells the body to pick up the sandwich and eat it. • When the five senses let the brain know that the body is eating some good tasting food and the stomach is filling up, special neurons in the reward pathway release the chemical dopamine. The release of dopamine gives you a little jolt of pleasure. That’s your reward for eating the sandwich.

13. Behavior and Memory • In addition to making you feel good when you engage in beneficial behavior, the reward pathway is responsible for trying to make sure  you repeat the behavior whenever possible. It does this by connecting to regions of the brain that control  memory and behavior. • When the reward pathway signals brain regions involved in memory, it enables the brain to create the memory that eating food makes you feel good. This increases the likelihood that you will eat the food again.

14. The End!! Thanks for Listening