Illicit drugs are those that are illegal to make, sell, or use. They include:

  • cocaine
  • amphetamines
  • heroin
  • hallucinogens

Many illicit drugs are highly addictive and pose serious risks. Using these drugs usually begins as an experiment or because of curiosity. Other times, it may start from using prescription pain medication prescribed to treat an illness or injury.

Over time, a user may become hooked on the mental or physical effects of the drug. This leads to the user needing more of the substance to get the same effects. Without help, a person with an illicit drug addiction will often put their health and safety in danger.

It’s important to remember that addiction isn’t a weakness or choice. According to the American Society of Addiction Medicine (ASAM), addiction is a chronic disease that causes people to seek reward or relief through substances or other behaviors.

The effects of illicit drugs depend on the type of drug. Drugs are grouped into categories based on their effects:


Stimulants include cocaine or methamphetamines. They cause hyperactivity and increase heart rate and brain activity.


Opioids are painkillers that also affect chemicals in the brain that regulate mood. They can also depress or slow down the central nervous system and affect breathing.


Marijuana, psilocybin mushrooms, and LSD are all considered hallucinogens. They alter the user’s perception of space, time, and reality.

Depressants or sedatives

These drugs aren’t always illicit. But people may get addicted to prescription medications of all kinds. If drugs are used in ways they weren’t prescribed by someone addicted to illicit drugs, they may end up stealing to maintain their supply.

Some people addicted to illicit drugs might mix several different substances together. They may also alternate between taking different drugs. But no matter how the drugs are taken, there are certain behaviors that may indicate an addiction:

  • significant, unusual, or sudden changes in energy level
  • aggressive behavior or violent mood swings
  • preoccupation with getting and using drugs
  • withdrawal from friends and family
  • new friendships with other users
  • attending social events where the drug will be present
  • chronic health problems or continued use of the drug despite physical risks
  • behavior which violates one’s personal morals or values in order to obtain the drug
  • legal or professional consequences from illicit drug use, such as an arrest or loss of a job

There are also specific symptoms associated with certain categories of illicit drugs.


Signs of stimulant drug abuse include:

  • increased blood pressure or body temperature
  • weight loss
  • diseases related to vitamin deficiencies and malnutrition
  • skin disorders or ulcers
  • insomnia
  • depression
  • consistently dilated pupils


Opioid addiction can cause:

  • immune system weakness through malnutrition
  • infections passed through blood
  • gastrointestinal issues
  • difficulty breathing

Drugs like heroin make you drowsy, so abusers will seem like they are extremely tired. Also, when a user doesn’t get enough of a drug, they can experience:

  • chills
  • muscle aches
  • vomiting


Hallucinogen abuse is more common than hallucinogen addiction. Signs of abuse can include:

  • dilated pupils
  • uncoordinated movements
  • high blood pressure
  • dizziness
  • vomiting

In some cases, there may also be suicidal or violent moods.

Treatment for illicit drug addiction could involve inpatient or outpatient treatment and then maintenance treatment. Often it can be difficult for someone addicted to drugs to stop using them and stay sober without professional help.

The withdrawal process can be dangerous and damaging to the health of the user. Many people need to be under a doctor’s supervision for the first few weeks of sobriety so they can detox safely. A combination of the following treatment options may be necessary:

Inpatient rehabilitation program

An inpatient program is often the best start for a person with an addiction to illicit drugs. Doctors, nurses, and therapists monitor the person to make sure they’re safe.

In the beginning, the person may have several negative physical symptoms as their body adjusts to not having the drug.

After the physical withdrawal, they can focus on staying clean in a safe environment. The length of inpatient programs can vary. It depends on the facility, situation, and insurance coverage.

Outpatient rehabilitation program

In an outpatient program people attend classes and counseling at a facility. But they continue to live at home and attend daily activities like work.

12-step programs

Programs like Narcotics Anonymous (NA) and Drug Addicts Anonymous (DAA) follow the same recovery method as Alcoholics Anonymous (AA).

These programs are centered on principles known as the 12 steps. A person is confronted by their addiction and will learn to develop new coping behaviors. These programs also act as support groups by involving other people with addictions.

Psychotherapy or cognitive behavioral therapy

A person with addiction may benefit from individual therapy. Drug addiction often involves emotional issues that need to be dealt with in order to change self-destructive patterns.

Also, a therapist can help someone with a drug addiction cope with the emotions involved in recovery. A person with addiction may have to deal with depression, guilt, and shame.


In some cases, medication is necessary to help overcome cravings or urges. Methadone is a drug that can be used to help heroin addicts beat addiction. Also, buprenorphine-naloxone is available to help people with opiate addictions manage cravings.

Sometimes people self-medicate. They turn to drugs to deal with mental health issues. In this case, antidepressants can help the recovery process.

Illicit drugs can often alter brain chemicals. This could complicate or uncover preexisting mental health conditions. Once the regular substance abuse has stopped, these mental health conditions can often be managed with the right medication.

There are some organizations that help with illicit drug addiction and treatment. These include:

People close to the person with the addiction often deal with stress of their own during a loved one’s addiction or recovery. Programs like Al-Anon can help the families and friends of someone with an addiction find support.

Illicit drug addiction can be treated. But it can be a difficult process, physically and emotionally. People with addiction often say they are never “cured.” They learn to cope with their disease.

Relapses can occur but it’s important that the person seeking treatment gets back on track and continues treatment.

It’s also important to develop a strong support system that includes sober people to help with long-term recovery.