Chemistry of Addiction

Neurons transmit messages in the brain. They are responsible for passing chemical and electrical signals throughout the brain. They come in many shapes and sizes so that they have specialized functions in the body. Reward pathways sit in the center of the brain. They are responsible for driving our feelings and motivation. The main job of the reward system is to make us feel good while we partake in activities crucial to our survival, such as eating, drinking, and sex. Outside factors can influence your reward system. The brains can also store memories relating positive things to these crucial activities. The reward pathways are also responsible for ensuring that you repeat the behaivor. Neurons communicate through the synapse. The information flows across the small gap, and the electrical signals are translated to chemical signals to cross the gap. There are also other cells in the brain that influence complex brain function, such as glia.


Drugs alter the brain's reward pathway. Drugs create dramatic changes to the synapses in the brain. By bypassing the 5 senses, drugs can cause a jolt of intense pleasure. Drugs of abuse influence the brain in such a drastic way that the brain has to try to cope with it.


Alcohol: Taken by drinking. It is a depressant, which causes a relaxed or drowsy effect. It causes loss of motor coordination, impairs reasoning, balance, speech, reaction, time, and judgment. In large amounts, it can cause nausea, vomiting, lack of physical control, loss of consciousness, and death.


Steroids: Taken by mouth or injection. They are man-made chemicals similar to male sex hormones. They are sometimes used to treat medical conditions. It also promotes muscle growth, so they are used by athletes and bodybuilders. Steroids can cause heart and liver problems, as well as undesirable physical effects.


Cocaine: Taken by snorting, injecting, or smoking. It's a powerful stimulant which speeds up activity in the brain and nervous system. Cocaine causes increased energy, decreased appetite, and mental alertness. It is also very addictive. Causes nausea, disturbances in heart rhythm, respiratory failure, and seizures. It has very severe withdrawal symptoms.


Dissociative Drugs: Taken by snorting, smoking, or by mouth. PCP is most often smoked, and gives the user a sense of detachment from reality. It can cause convulsions, comas, high fever, or death. Ketamine is similar to PCP, but is less potent. Some users experience a terrifying feeling. Dextromethorphan is a cough suppressant that can have effects similar to PCP and Ketamine in high doses.


GHB and Rohypnal: Taken by mouth. GHB is a depressant which causes relaxation. In high doses, it causes seizures, loss of consciousness, comas, or death. Rohypnol is a benzodiazepine which is used to treat anxiety disorders. In abusive doses, it can be deadly.


Hallucinogens: Taken by mouth, snorting, or smoking. They cause hallucinations. Physical effects are dialated pupils, higher body temperatures, increased heart rate and blood pressure, sweating, loss of appetite, sleeplessness, dry mouth, and tremors.

Heroin: Take by inject, snorting, or smoking. It is the most widely abused opiate. Heroin causes a rush of pleasure, which is followed by drowsiness. Its side effects are nausea, vomiting, and severe itching. Heroin is extremely addictive.  The withdrawal symptoms include restlessness, muscle and bone pain, insomnia, diarrhea, cold flashes, and vomiting.


Inhalants: Taken in various ways through the nose and mouth. They are chemicals that can he inhaled to get an instant high. The chemicals are found in many household products. They affect the brain with great force, and can cause brain damage or death. 


Marijuana: Taken by smoking. It is the most commonly used drug in the US. It causes a peaceful and euphoric sensation, and after wearing off the person may feel drowsy or depressed. It impairs memory, reaction time, balance, and coordination. 


MDMA: Taken by mouth. It acts as a stimulant and a hallucinogen, and produces energizing effects and distortions of reality. It causes chills, muscle cramping, teeth clenching, and reduction oif mental abilities. Overdosing can cause panic attacks, loss of conciousness, and seizures. It also puts you at risk of dehydration, hyperthermia, and heart or kidney failure.


Meth: Taken by mouth, snorting, injecting, and smoking. It is a strong stimulant drug. It causes mental alertness and increses energy, but has toxic effects on the brain. It can elevate body temperature and cause convulsions. Long term users may develop violent behaivor, anxeity, insomia, paranoia, delusiouns, and dependancy to the drug. 


Nicotine: Taken by smoking, chewing, and dipping. It is the addictive substance in tobacco. It acts as a stimulant or sedative. It can be very addictive. Quitting can cause cravings, irritability, and sleep disturbances. It is also a major cause of cancer, being responsible for at least 30% of all cancer deaths.




There are many ways that the drug can reach the brain. Studies have shown that the quicker the drug reaches the brain, the more addictive it may become. Different methods of delivery-smoking, injecting, or snorting. The fastest way to get a drug to the brain is by smoking it. The delivery method can affect what part of the brain is most affected by the drug. 


Once someone gets addicted to drugs, the brain is practically hardwired to needing the drug. The behaivor becomes driven by habit, and becomes almost like a reflex. 

Drugs can kill. Some combinations of drugs are lethal, such as heroin and alcohol. Heroin is the largest killer of the drugs, usually leading to respiratory failure. Alcohol can slow breathing to be non-existent, and can also cause vomiting. It is possible to overdose on nicotine by using several methods of delivery at once. Cocaine increases your risk of having a heart attack, even after one time.
Amphetamine, Methamphetamine, and MDMA can also kill, resulting in heart attacks, overheating, and brain damage.