Various drugs produce different effects on the brain, but their major impact is revealed in violating the way neurons pass signals with the help of neurotransmitters.
Certain drugs including marijuana and such heavy substances as heroin can activate the neurons because their structure resembles the structure of neurotransmitters.
This allows stimulating the neurons.
Even though drugs resemble the brain’s natural chemicals, they do not work similarly.
Such stimulants as amphetamine or cocaine may provoke the release of abnormally large quantities of natural chemicals and prevent the brain from functioning normally.
This violates the usual functioning of the neurons.
Drugs also damage certain vital areas of the brain and can provoke addiction.
Some drugs such as opioids also influence other brain parts including the brain stem, which regulates our elementary functions such as heartbeat and sleeping.
In this respect, an overdose may provoke changes in breathing patterns and even cause lethal outcomes.
Another effect of drugs is the feeling of pleasure also known as euphoria.
It is not quite clear how it works but it is assumed that it also changes the way neurotransmitters operate.
The less perceptible feeling of pleasure can be equally achieved by eating favorite foods or listening to music, or in other words, stimulating our reward system.
Drugs, however, produce many times more perceptible effect on our feeling of happiness and the ability to experience euphoria.