Illegal Drug Abuse

Medically reviewed by:
John Nguyen, B.S.

Table of Contents

What is Illegal Drug Abuse?

Illegal drug use in the United States is increasing. In 2013, 24.6 million Americans 12 or older (9.4% of the population) had used an illicit drug in the past month.

People use illicit substances for several reasons:

  • To feel good. Drugs produce an intense feeling of pleasure and euphoria.
  • To feel better. People use drugs to cope with anxiety and depression. Stress often causes people to continue using and relapse.
  • To do better. Some people feel the need to increase their ability to focus or perform.
  • Curiosity and social pressures.

A Substance Use Disorder (SUD) is a medical condition diagnosed when the usage of one or more substances results in mental, physical, and behavioral symptoms that cause clinically significant impairment such as loss of self-control, strain to one’s social life, dangerous use, tolerance, and withdrawal syndromes.

Types of Illegal Drugs Abused

Here are the most commonly used illegal substances in the United States:


Cocaine is a stimulant that is derived from the leaves of the coca plant. Recreationally, cocaine appears as a white powder and causes euphoria and psychosis. Cocaine is commonly snorted, smoked, or injected, sometimes in combination with heroin (Speedball). It is often laced with other such drugs such as opioids like fentanyl, amphetamines like meth and even local anesthetics. Other names for cocaine include blow, coke, and snow. Cocaine increases levels of dopamine in brain circuits related to the control of movement and reward. Adverse effects include cocaine dependence, addiction, stroke, heart attack, lung problems, blood infections, decreased pleasure, and tiredness. Medication treatment for cocaine addiction is limited, but behavioral approaches have proven to be effective.

In addition to cocaine, crack is a more solid form of the drug that is smoked. It causes a shorter, more intense high than when ingested in powder form. Crack is the most addictive form of cocaine.

Ecstasy (MDMA)

Ecstasy, or MDMA, is a synthetic drug that alters one’s sensations and perception. It is commonly called Ecstasy (“E”) or Molly. Those who use MDMA usually consume it as a capsule or tablet often in combination with other drugs. The effects include increased energy, altered sensations such as increased pleasure, and distorted perception such as increased empathy. MDMA works by increasing the activity of dopamine, norepinephrine, and serotonin within the brain. Adverse effects include addiction, memory issues, paranoia, sleep problems, teeth clenching, blurry vision, sweating, rapid heart rate, hyperthermia, dehydration, depression, and tiredness. There are no specific medical treatments for ecstasy addiction, but people have found behavioral therapy to be most effective.


Heroin is an opioid that is created from morphine. Recreationally, heroin is also known as black tar and causes significant euphoria. People use heroin either by snorting, smoking, inhaling, or typically dissolving the white/brown powder in water and injecting it. As heroin enters the central nervous system, it binds to opioid receptors, which are involved in pleasure and pain. Side effects include decreased respiratory rate, dry mouth, drowsiness, decreased cognitive function, constipation, and addiction. Long-term consequences of users who inject heroin can be infective endocarditis (infection of the heart valves), abscesses at the injection site, blood infections, and pneumonia. Withdrawal symptoms consist of agitation and anxiety, muscle and bone pain, sleep problems, diarrhea and vomiting, increased heart rate and blood pressure, abdominal cramps, and severe cravings. Naloxone is an opioid antagonist that can treat a heroin overdose. Heroin addiction is treated is through a combination of medication and behavioral approaches.


Methamphetamine (Meth) is a stimulant that is similar to amphetamine that is used in the treatment of ADHD, narcolepsy, and obesity. On the streets, it typically takes the form of a white powder, or also a pill. Further, crystal meth usually appears like clear, see-through glass or shiny, bluish-white rocks. People use meth either by smoking, swallowing, snorting, or injecting. Meth acts by increasing mainly dopamine in areas of the brain involved in movement, motivation, and reinforcement of rewarding behavior. The short-term health effects include elevated mood, increased wakefulness and physical activity, decreased appetite, hypertension, and hyperthermia. Adverse effects at high doses consist of psychosis, mood swings, violent behavior, skeletal muscle breakdown, seizures, and brain bleeding. Long-term complications can be risk of addiction, risk of contracting HIV and hepatitis, dental problems (“meth mouth”), and intense itching that leading to skin sores from scratching. When people stop taking it, withdrawal symptoms include psychosis, dysphoria, depression, anxiety, fatigue, drug cravings, increased appetite, movement issues, lack of motivation, and sleep problems. Because overdose often leads to a stroke or heart attack, initial treatment involves preventing these two conditions. The most effective treatment for meth addiction is behavioral therapy.

What are the Side Effects of Illegal Drug Abuse?

While each individual substance has their own associated side effects as mentioned above, the common one that is of most concern is addiction. Addiction is a chronic, relapsing disorder characterized by compulsive drug-seeking behavior. It involves functional changes to brain neurocircuits involved in reward, stress, and self-control.

Beyond the harmful consequences of addiction, illicit drug use also causes severe effects for others:

  • Negative effects of drug use while pregnant or breastfeeding
  • Negative effects of second-hand smoke
  • Increased spread of infectious disease
  • Increased risk of MVA’s (motor vehicle accidents)

What are the Signs of an Overdose on Illegal Drugs?

Signs of an illicit drug overdose depend on the specific drug used. Common ones include changes to blood pressure, heart rate, breathing rate, body temperature, pupil size, bowel sounds, and sweating. Others include blue lips and nails due to low oxygen levels, muscle spasms, seizures, and decreased consciousness, which are all often specifically seen in opiate overdoses.

Treatment Options for Illegal Drug Abuse

While there isn’t a general cure for drug addiction, like other chronic diseases it can be managed successfully. Different types of medications, depending on the drug addicted to, are useful at different phases of treatment in order to help users stop abusing drugs, remain in treatment, and prevent relapse.

Behavioral therapies assist users in drug addiction treatment by modifying their attitudes and behavior towards drug use. These include:

  • Cognitive-behavioral therapy
  • Contingency management
  • Motivational enhancement therapy
  • Family/couples therapy
  • Group therapy, such as twelve-step facilitation
  • Recovery support services

Cognitive Behavioral Therapy

Cognitive and behavioral therapy (CBT) is a goal-oriented psycho-social intervention that is commonly used in psychiatric disorders and medical conditions such as addiction. CBT works by identifying and correcting specific behavioral patterns that are seen with drug abuse. Patients who undergo CBT learn to develop coping strategies, self-control, and learn to identify drug cravings. When used with other behavioral therapies and in combination with certain medications, CBT has been shown to effectively prevent relapse through for example adjunct completion of a 12-step program.

Contingency Management

Contingency management (CM) is a widely used therapeutic method that involves operant conditioning. This involves reward and punishment for adherence or failure, respectively, to rules and regulations of a patient’s treatment program. CM has been proven to be very effective in treating substance addiction.

Motivational Enhancement Therapy

Motivational interviewing is a methodology that helps patients invoke inward/internal sources for overcoming addiction and has demonstrated positive outcomes such as decreasing SUD, and improving treatment engagement in a wide range of populations. In conjunction with other behavioral interventions, motivational interviewing has been shown effective for SUD specifically involving heroin, cocaine, and nicotine.

Family Therapy

Family Behavior Therapy (FBT) involves behavioral contracting with a parent or one’s partner. During FBT, strategies are provided in order to improve their home environment in order to prevent drug abuse. Parents are instructed to set goals, and provide incentives when these are reached.

Twelve-Step Facilitation

Twelve-Step Facilitation (TSF) is delivered over 12 to 15 sessions that provide a structured approach for the recovery from alcoholism and drug abuse. The goal of a 12-step program is acceptance and surrender. When one accepts their issue, they acknowledge their need for abstinence from the substance and are actively willing to participate in a program to maintain sobriety. This treatment method is generally provided in an outpatient community setting, where one’s active participation in self-help groups is the cornerstone of successful outcomes. Common self-help groups include Alcoholics Anonymous (AA) and Narcotics Anonymous (NA). TSF programs are frequently used with other behavioral therapies and in combination with certain medications.

Recovery Support Services

Recovery support services (RSS) can also be used where patients try to improve their health and wellness to reach their fullest potential through continuous growth and improvement. There are 4 main components of RSS, which include health, home, purpose, and community. Relationships and social networks are used to actively engage the individual in these various support services.