Drugs and Its Effects on the Brain


Issues of drug abuse are always common in modern times. Most governments have set regulations to govern the sale and use of different drugs. Drug barons have always found themselves in trouble once they are caught up by the law. Whereas such barons make fortune out of such drugs, drug addicts always suffer from withdrawal symptoms and sometimes death.

It is important to understand the various drugs that exist. This knowledge is important not only for scientific reasons. Rather, psychiatrists use this knowledge to offer therapeutic counseling to the drug addicts. This paper gives an outline of how various drugs affect the functioning of the human brain.

Major Categories

Drugs can be categorized into four major groups namely: depressants, stimulants, opiates and hallucinogens. Depressants include alcohol, sedatives and volatile solvents. The effect of these drugs is to reduce the activity of the central nervous system (CNS). Stimulants include nicotine, amphetamines and ecstasy. Their effect is to activate the CNS. Opiates include heroin and morphine. They are associated with the dulling of senses and induction of sleep. Hallucinogens, as the name suggests, induce delusions. The effects of some of these drugs on the human brain are discussed next.


Alcohol is commonly abused. Alcohol is usually in form of wines, spirits or beer. Persons who abuse alcohol are characterized by impaired vision, distorted hearing, impaired judgment, dull senses, disturbed motor skills and reduced coordination. In addition, brain areas that control aggression, hunger, thirst, pleasure, pain and body temperature are affected.

The inhibition of blood to transport oxygen to blood cells is encountered. Alcohol deprives the brain cells of oxygen rendering them impaired or dead. The fact that brain maturation takes place gradually may be problematic to young people who abuse alcohol. Some irreversible effects of alcohol may be undesirable.


Amphetamines are associated with the release of neurotransmitters dopamine and norepinephine. The release of these neurotransmitters into the synapse causes feelings of pleasure and euphoria, brain swelling, brain hemorrhage, paranoia and hallucinations. In addition, changes in the dopamine-producing neurons may be observed. The ultimate effect of the changes is Parkinson’s disease. The drugs may also be characterized by high blood pressure, irregular heart rate and chest pain, shortness of breath, nausea, vomiting and diarrhea.


Hallucinogens are characterized by lack of sleep, trembling, raised heart rate and raised blood pressure. People who use LSD bear extreme emotional feelings. The crossing of senses may also be encountered. In addition, actions of other neurotransmitters are disrupted. The fact that the effects of these drugs are unpredictable makes them unique. The drugs are associated with two extreme scenarios. Whereas people hallucinate and become aggressive, others become drowsy and passive.


Opiates are associated with increased feelings of pleasure, relaxation and contentment. Their action on the brainstem stops coughing and slows breathing. Constricted pupils, watery eyes and itchy sensations are observed in people who use the drug. Drug abuse is associated with shallow breathing, clammy skin, convulsions, coma and ultimately, death.

The conversion of heroin into morphine causes opioid receptors to be impaired. Opioid receptors are majorly concerned with key processes such as respiration and blood pressure. Abuse of heroin suppresses respiration since morphine is attached to the opioid receptors. Intravenous injection of heroin causes euphoria, warm flushing of the skin and clouded mental functioning.

Regular use of heroin is associated with tolerance. Consequently, psychological and physiological response levels are reduced. This leads to more craving to achieve the desired effects. Statistics indicate that heroin users have a greater risk of becoming dependent on it. 23% of heroin users are potential heroin addicts.


Generally, drugs interfere with the communication mechanisms between brain cells. Some drugs imitate the effects of neurotransmitters, while others interfere with the brain’s functioning by blocking it. Others interfere with the storage, release and removal of neurotransmitters. Exposure to stimuli provokes cravings among drug-dependant people. Consequently specific locations within the forebrain are activated. Drug use and dependence also cause abnormal functioning of specific brain parts.


Drug addiction is a brain disorder that accrues from use of psychoactive drugs. Normal processes such as perception, emotion and motivation are affected. As a result, the thoughts and behavior of drug-dependant people are affected. Drug dependant persons show a strong desire for the drug, have difficulty in control of drug use and encounter withdrawal symptoms. In addition, increased doses of the drug and persistence in drug use are major causes of addiction.


It is important to ensure that drug use does not go beyond acceptable limits. It is vitally important for drug users to understand the risks posed by some psychoactive drugs. The desire to acquire stimulation may be the genesis of long term brain dysfunction. Drugs cause different effects to the brain.

However, all psychoactive drugs are common on grounds that the ultimate body organ affected is the brain. Drug users should be aware of the risks associated with each drug in order to avert serious brain disorders in future. A clear understanding of how the brain reacts to various drugs is also important.


‘Your Brain’s Response to Drugs.’ Web.

NIDA InfoFacts: Heroin. The Science of Drug Abuse & Addiction. Web.

‘Psychoactive Drugs.’ Web.

Find out your order's cost