There are three basic characteristics that indicate that the user is dependent on a drug. First, the user continues to use the drug for an extended period of time. Second, the user finds it difficult to stop using the drug. They may drop out of school, steal, go to jail, lose their jobs, or leave their families in order to keep using. Finally, the user has withdrawal symptoms when drug use is stopped. They may undergo physical pain or mental distress. The drug mimics a natural process in the brain called neurotransmission. This is when a brain cell releases a signal to another brain cell. The signal then returns to the first brain cell. The signal is called a neurotransmitter. One major neurotransmitter is called dopamine, which is involved in feelings of pleasure. When the drug is released into the brain, it blocks the dopamine from return

One of the most powerfully addictive and deadly drugs is cocaine. It can be injected, snorted, or smoked. It carries the risk of HIV if it is injected. Cocaine significantly speeds up the neurotransmissions in the nervous system. It accelerates the heart rate while simultaneously constricting the blood vessels, which are trying to adjust to the heightened blood flow. Temperature and blood pressure rise. Pupils dilate. These physical changes may be accompanied by stroke, respiratory arrest, cardiac arrest, or seizures.

PCP is a hallucinogen. It alters consciousness, mood, and sensation and distorts visual sensation, taste, smell, touch, or hearing. The user experiences a profound departure from reality. He/she is capable of severe disorientation and bizarre behavior. These PCP-induced effects may lead to injuries or death while under the influence.

Some topics in this essay:
Alcohol Syndrome, Effects Drugs, Drug Dependence/Addiction, HIV Contamination, Drug Treatment, PCP PCP, Classification Drugs, Withdrawal Withdrawal, Heroin Heroin, Drug Abuse, withdrawal symptoms, brain cell, stage user, blood pressure, nervous system, dependent drug, drug abuse, nervous system produce, treatment therapy, drug addiction, runny nose, user dependent drug, signals nervous system, brain cell signal,