The Biology of The Biology of AddictionAddiction

By Dr. SpringerUniversity of Nebraska-Lincoln

What is Drug Addiction?What is Drug Addiction?

NIDA (National Institute on Drug Abuse) defines addiction as: a “chronic relapsing brain disease that is characterized by compulsive drug seeking and use, despite harmful consequences.

It is considered a brain disease because drugs change the brain… Its structure and how it works, forever!

Why do people take drugs?Why do people take drugs?

To feel goodTo feel betterTo do betterCuriosity (Everyone’s doing it)

Peers and SchoolPeers and School

Environmental factor◦Shy or aggressive classroom behavior◦Poor school performance◦Poor social coping skills◦Affiliation with deviant peers◦Perceptions of approval of drug-abusing

behaviors in environment (school, peers, home)

Addiction and the BrainAddiction and the Brain

Addiction is a developmental disease that typically begins in childhood.

Prefrontal cortex: affects regulation, emotional control, sound decision-making, higher level thinking.◦Develops rapidly during adolescence◦Substances interfere with normal development

of this area

Healthy Brain DevelopmentHealthy Brain Development

3 Areas affected 3 Areas affected by drug abuseby drug abuse1- Brain Stem: Controls functions critical to life.I.e. heart rate, breathing

2- Limbic System: The brain’s reward circuit.It is highly implicated by emotions

3- Cerebral Cortex: Controls specific functions. It enables us to see, feel, hear, and taste. The frontal cortex is the reasoning center of the brain.

Drugs decrease brain functionDrugs decrease brain function

How do drugs affect the brain?How do drugs affect the brain?

Drugs tap into the brain’s communication system and interfere with the way neurons normally send, receive and process info.

All drugs of abuse directly/indirectly target the brain’s reward system by flooding the circuit with Dopamine.

Dopamine is a neurotransmitter that indirectly regulates emotion, cognition, and pleasure.

Drugs and AddictionDrugs and Addiction

Our brains are “hard-wired” to appreciate and to pursue natural rewards because of their critical survival value.

Drugs activate the same circuits that motivate eating and sexual behavior.

Eventually cravings for the drugs can exceed those for food or sex.

Drugs vs. Natural RewardsDrugs vs. Natural Rewards

When drugs are taken, they release 2-10 times the amount of dopamine that natural rewards do!

This overwhelms the reward circuit in the brain as well as changes brain function.

This results in the brain trying to get back to its natural levels, and thus stops producing and/or receiving dopamine (the crash).

Other changes in the brainOther changes in the brain

Chronic exposure to drugs disrupts the way critical brain structures interact to control behavior.

In other words, drug addiction erodes a person’s self-control and ability to make sound decisions.

Diseased Brain & HeartDiseased Brain & Heart

Addiction is similar to other diseases such as heart disease.

Both disrupt the normal, healthy functioning of the underlying organ, have serious consequences, are preventable, treatable, and if left untreated, can last a lifetime.

The Three The Three CC’s of Addiction’s of Addiction

Compulsion: Obsession with alcohol and/or drugs

Control: Inability to stop usingConsequences: Continue to use despite

adverse consequences

Meth Abuser Brain ImagingMeth Abuser Brain Imaging

Proactive FactorsProactive Factors

Strong/positive family bondsParental monitoring of children’s activitiesClear rules; consistently enforcedSuccess in schoolBond with an institution (church)Understanding conventional norms about

abuse