Drugs are chemically or naturally derived substances that affect our physical and mental states. While many drugs are used to treat many medical conditions, some drugs are sought out for recreational, non-medical use due to their psychoactive effects and may also be illegal. Both categories use the same term, which is why the term “drugstore” is widely used as an innocuous destination, while the term “drug dealer” tends to be vilified.

The drugs most often used for recreational purposes fall into four main classifications. These substances feature a wide range of effects, which can be either short-lived or of long duration. However, the characteristic they all share is a risk of developing drug dependence or substance use disorder (SUD) with continued use.

What substances are considered “drugs”?

Recreational drugs are substances or compounds that interact with brain chemistry, resulting in certain effects. Recreational drug use is driven by a desire to experience a “high.” These effects may include a sense of euphoria, deep relaxation, a burst of energy, a boost in confidence, or a temporary break from reality. The brain’s reward system tends to register these effects as something desirable that should be experienced again.

Depending on the class of drug, the active chemicals can also have a powerful effect on the central nervous system, resulting in physical changes to the body’s operation. Some examples include:

• Changes to respiratory rate
• Changes to heart rate
• Blocking of pain signals
• Changes to body temperature
• Loss of coordination
• Hallucinatory effects, causing one to see or hear things that aren’t there
• Changes to the body’s rate of movement
• Changes to appetite
• Significant alterations in sleep patterns

The brain’s pathways can become altered once a pattern of continued use is established. In such cases, the brain becomes dependent on the chemical effects of the drug for dopamine production. This eventually causes the individual to become trapped in chemical dependency or an SUD.

What are the different types of drug classes?

There are four basic classes of recreational drugs of abuse. Some of them are legal medications and some are illicit substances with no medicinal value at all.

The four types of drugs include:

• Depressants: These are drugs that slow or depress the functions of the central nervous system and brain. Depressants attach to the brain’s neurotransmitters and increase levels of gamma-aminobutyric acid (GABA). When GABA levels increase, nerve cell signals are suppressed, leading to a sense of deep relaxation. Examples of depressants include alcohol, benzodiazepines, barbiturates and hypnotics.
• Stimulants: Drugs that accelerate the central nervous system are called stimulants. These short-acting drugs cause the brain to produce dopamine, which leads to a powerful surge of energy and confidence, as well as a reduced need for sleep or food. Examples of stimulants include cocaine, methamphetamine and prescription stimulants like Adderall and Vyvanse.
• Opioids: Drugs that are used to suppress physical pain are called analgesics or opioids. Some opioids are naturally derived, such as the poppy plant, while others are lab-created. Opioids work by attaching to the opioid receptors in the brain, which then block pain signals from the nervous system. Examples of opioids include heroin, morphine, fentanyl, oxycodone, hydrocodone, hydromorphone, meperidine and methadone.
• Hallucinogens: Drugs that alter consciousness or the perception of reality are called hallucinogens. These substances, sometimes called psychedelics, can be naturally-derived, such as certain plants or mushrooms or lab-created. The psychoactive effects can include detachment from reality, hallucinations, paranoia, violent behaviors, distorted perceptions, euphoria, agitation, and fear. Examples of hallucinogens include lysergic acid diethylamide (LSD), phencyclidine (PCP), ketamine, mescaline, psilocybin and high-potency cannabis.

What are the withdrawal symptoms for different types of drugs?

While withdrawal symptoms are a key indicator for an SUD, each drug class (and drug) can exhibit different ones.

Here are the withdrawal symptoms broken down by drug class:

• Depressants such as alcohol and Xanax:
  • seizures
  • agitation
  • shakiness
  • anxiety
  • increased heart rate
  • overactive reflexes
  • high blood pressure
  • fever and sweats
  • hallucinations
  • severe cravings
  • insomnia

• Stimulants such as cocaine and amphetamine
  • severe cravings
  • insomnia
  • impaired cognitive function
  • mood swings
  • chills
  • body aches
  • tremors and shakiness
  • fatigue
  • exhaustion
  • difficulty concentrating
  • depression
  • anxiety

• Opioids such as heroin and Suboxone
  • agitation
  • anxiety
  • muscle aches
  • insomnia
  • runny nose
  • sweating
  • yawning
  • increased tearing
  • abdominal cramps
  • diarrhea
  • dilated pupils
  • goosebumps
  • nausea and vomiting

• Hallucinogens such as high-potency marijuana
  • flashbacks
  • muscle spasms
  • loss of coordination
  • aggressive, hostile or violent behavior
  • zombie-like state
  • high blood pressure
  • increased heart rate
  • fear of going insane
  • depression
  • psychosis
  • hyperthermia
  • diarrhea
  • permanent post-hallucinogenic perceptual disturbance
  • long-term psychosis

While these four types of drugs are unique in the way they interact with our body, they do share a common feature. All of these drugs are potentially addicting and even deadly if misused.