When it comes to the way drugs make us feel, they were separated in a few categories:
- Depressants( or CNS - Central nervous system) : alcohol, barbiturates, anti-anxiety tranquillizers and many others
- CNS Stimulants - they have a rapid effect on the body - heart rate going up, adrenaline, sweats, etc. : cocaine, "crack" cocaine, amphetamines, and methamphetamine.
- Hallucinogens- these alter perception: LSD, ecstasy, etc
- Anaesthetics;
- Narcotic Analgesics: pain relief - opium, codeine, heroin, Demerol, Darvon, morphine, methadone, Vicodin, and Oxycontin.

Inhalants: a variety of commonly used products like- plastic cement, paint, gasoline, paint thinners, hair sprays, and various anaesthetic gases.
Depending on the types of drugs someone is trying to use, the brain is being affected differently, in most cases negatively in the long term.
 From something just as simple as alcohol or cigarettes that we can find in normal shops to stronger ones like cocaine, heroin, etc.
In the long run, the body and the brain are becoming addicted to the substances and get feelings of uneasiness and anger when in withdrawal of any type.
Studies show that a multitude of people end up using different types of drugs as depressants, to help with their mental health, without realising.
The body is storing trauma from the brain, even when we maybe forget traumatic events, which results in having maybe certain days of the year when we are sad for no apparent reason and we tend to rely on.
''Regions of the brain are disrupted by drug abuse, as the National Institute on Drug Abuse (NIDA) reports that the brain stem, limbic system, and cerebral cortex are all affected. The brain stem controls life-sustaining functions, including sleeping, breathing, and heart rate, while the limbic system holds the brain’s reward circuitry and helps to control emotions and the ability to feel happiness. The cerebral cortex is considered the “thinking center” of the brain, managing problem-solving, planning, and decision-making abilities as well as helping people to process information provided by their senses. The more often drugs are used, the more they will impact brain chemicals and circuitry, which can lead to drug dependence and withdrawal symptoms when the drugs process out of the body. Drug cravings, dependence, and withdrawal symptoms, coupled with a loss of control over use, are signs of addiction.'' says the American Society of Addiction Medicine.
As part of my personal research, I started to ask people whether or not they use depressants as a form of coping mechanism. 
My biggest surprise is that the most used depressant people I interacted with is not weed, alcohol or tobacco. It's Caffeine. 
Caffeine increases activity in your nervous system and in small quantities, it can help you feel energised. 
It is a depressant drug. 
My opinion is that caffeine is so over-consumed because of a few internal and external factors. 
One would be marketing since coffee is pretty much everywhere. It is very accessible, it has a great taste, it comes in different packages and in a way it represents a feeling, maybe a different one for each of us. 
Another one would be accessibility and price as well as the fact that, unlike other drugs, caffeine isn't followed by the same stigma or social issues.