Drugs such as narcotics and pharmaceutical or prescribed medications can be abused by people and result in severe effects on the brain. Abuse can cause short-term memory impairment, damage cognitive abilities of the brain and cause hallucinations. Drugs are abused when taken frequently or excessively without cause. This causes the effect of a mental addiction that can't be controlled without causing severe withdrawal symptoms. According to the Cleveland Clinic, an addiction or dependence causes the brain to crave the drug and feel physical symptoms without it, even though the drug is damaging the brain and body.
Short-Term Memory Impairment
Abuse of the drug marijuana often causes short-term memory loss. The main psychoactive component of marijuana binds to the cannabinoid receptors throughout the brain. Many of these receptors are located within the hippocampus, the area of the brain that's responsible for memory. According to the National Institute on Drug Abuse, when the marijuana components are bound to the cannabinoid receptors in the brain, this affects the capability of those neurons to transfer information efficiently. Though short-term memory loss is an acute side effect of marijuana use, it can lead to more serious memory problems for the drug abuser.
Hallucinations
Abuse of hallucinogens--namely LSD or d-lysergic acid diethylamid and PCP or phencyclidine--can cause unpredictable side effects on the brain. Hallucinations, which are distortions in perception of reality, occur when these drugs are abused. MayoClinic.com says LSD causes the brain to misinterpret the incoming sense. For example, the brain may confuse colors and sounds. PCP, on the other hand, was developed as an intravenous anesthetic but was discontinued after causing severe side effects. PCP has many affects on the limbic system, the part of the brain that controls emotions and behavior. An abuser of PCP drugs may become addicted to the sensation of empowerment and invincibility brought on by the hallucinogenic effects.
Mental Addiction
Heroin, one of the most abused drugs, is also listed as being the most addictive drug due to its opiate nature, according to the site DrugFree.org. Once heroin has reached the brain, it transforms into morphine and quickly binds to the opioid receptors throughout the brain. DrugFree.org says that a feeling of euphoria or a rush is a common effect. This drug depresses the central nervous system and all sensory pathways, causing the abuser to temporarily feel pain free and euphoric. These types of sensations become addictive and can only be regained by taking more heroin, which builds a tolerance and physical dependency of this drug. In the case of heroin, addiction may lead to death. The intake of high amounts of heroin can cause the medulla oblongata area of the brain stem to stop the process of breathing.
