The Centers for Disease Control and Prevention states that in 2007, 8 percent of people over the age of 12 in the United States used illicit drugs. Both drugs and alcohol affect the brain as soon as a person uses them, altering neurotransmitter levels in the brain, according to the National Institute of Drug Abuse. Neurotransmitters send signals throughout the brain, and affect how the brain functions. Over time, the substance abuse damages the brain and impacts normal neurological functions.
Neurotransmitter Levels
The immediate effect of substance abuse is euphoria, which drives a person to use the drug. The drug's impact on neurotransmitters causes this euphoric effect. Each drug causes different neurotransmitter reactions. For example, the Canadian Institutes of Health Research states that morphine mimics endorphin, causing the same effects on the brain as if endorphin was acting on its own receptors. Cocaine, on the other hand, increases dopamine, a neurotransmitter linked to pleasure. As a person continues to abuse these substances, they alter the brain's ability to produce the neurotransmitters on its own. As a result, substance abusers feel that they need to use more drugs to reach that level of euphoria.
Cognitive Changes
Drug and alcohol abuse can affect a person's cognitive functions, especially after regular use or with large doses of the drug. For example, the U.S. Department of Health and Human Services and the Substance Abuse and Mental Health Services Administration's National Clearinghouse for Alcohol & Drug Information note that large amounts of depressants, like barbiturates, can cause slurred speech and impaired judgment. Large doses of stimulants, like cocaine, may cause a loss of coordination, anxiety or delusions. An overdose of a stimulant may result in agitation and hallucinations.
Wernicke-Korsakoff Syndrome
A serious effect of long-term alcohol abuse is Wernicke-Korsakoff syndrome, which permanently damages memory. The National Institute of Alcohol Abuse and Alcoholism states that a thiamine deficiency causes Wernicke-Korsakoff syndrome, a deficiency that affects up to 80 percent of alcoholics. Wernicke-Korsakoff syndrome consists of two stages. The disorder starts with Wernicke's encephalopathy, which causes mental confusion. It then progresses to Korsakoff's psychosis, which affects memory and learning. Patients have retrograde amnesia, which impairs their ability to recall information, and anterograde amnesia, which causes problems when forming new memories. Because of the memory gaps, patients with Korsakoff's psychosis confabulate, or make up stories about events they do not remember. However, patients with Wernicke-Korsakoff syndrome do not realize that they are lying.
References
- Centers for Disease Control and Prevention: Illegal Drug Use
- Canadian Institutes of Health: The Brain from Top to Bottom: How Drugs Affect Neurotransmitters
- U.S. Department of Health and Human Services and SAMHSA's National Clearinghouse for Alcohol & Drug Information: Drugs of Abuse
- National Institute on Alcohol Abuse and Alcoholism: Alcohol's Damaging Effects on the Brain
- National Institute of Drug Abuse: Effects of Drugs of Abuse on the Brain
