How Substance Abuse Affects the Brain

Drug addiction is a chronic brain disease, one that an individual who abuses drugs can easily develop. Abusing drugs causes the brain's structure and function to change, resulting in harmful effects. These changes are the reason a drug abuser displays adverse psychological and behavioral symptoms.

How Drugs Operate

• Drugs enter the brain's communication system and interfere with how the nerve cells typically receive, send and process data. To accomplish this, drugs mimic the brain's authentic chemical messengers (neurotransmitters) or overstimulate the brain's pleasure center (reward circuit).

Marijuana and Opiates

• Marijuana and opiates such as heroin are designed with neurotransmitters that are similar to the chemical messengers that the brain naturally spawns. These drugs have the ability to trick the brain and send abnormal messages by activating the nerve cells.

Stimulants

• When an individual uses stimulants such as methamphetamine or cocaine, this can cause the nerve cells to release more natural neurotransmitters than usual. It can also stop the neurotransmitters from recycling, causing a disruption in the brain's regular communication system.

Commonality

• Dopamine is a natural chemical in the brain that controls emotion, movement, motivation and pleasurable feelings. Almost all drugs aim for the brain's reward system by releasing dopamine into its circuit.

Continued Abuse

• When an individual continues to use drugs, the brain adapts to the flood of dopamine and starts to produce less of it, or it may lower the amount of dopamine receptors (proteins) that are in the brain's reward system. This causes the dopamine to have less impact when released into the brain; tolerance develops and the individual uses more drugs, seeking the pleasure it once gave her.