Substance Abuse & Addiction Causes, Signs, Symptoms & Side Effects

No one experiences addiction the same way as someone else. Understanding the signs, symptoms and side effects of addiction is a key component toward starting the recovery journey.

Understanding Substance Abuse & Addiction

Learn about substance abuse & addiction

People abuse substances for a variety of complex personal reasons. However, the cost of drug abuse to the addict and to society is high. We can see the toll that substance abuse takes on our hospitals, emergency rooms, jails, and prisons. While the usage of some formerly popular drugs, such as cocaine, has declined over the years, usage of drugs like heroin and other club drugs has markedly increased.

While many effects of drugs of abuse are related closely to the particular drug that is being used, all substances of abuse have one thing in common: they provide the user with a level of mind-altering intoxication that changes judgment, perception, attention or physical control. Many substances of abuse, if the amount taken is reduced or stopped, produce withdrawal effects. Withdrawal from substances can be as mild as a minor anxiety or can be as severe as seizures or hallucinations. Overdose from drug abuse can cause death.

Nearly all drugs of abuse produce tolerance – the need for larger amounts of the drug to produce the same level of intoxication. Common drugs of abuse include the following:

Inhalants (also called “huffing”) is a process in which solvents that create intoxicating vapors are used. People who abuse inhalants huff these vapors intentionally in several ways: directly from the container, from the bag a substance is in, or from placing a rag soaked in the substance over the mouth or nose. The high from inhalants is short-lived but the damage caused by inhalants can damage the brain, heart, liver, and kidneys.

Marijuana (also known as “pot,” or “weed”) comes from the plant Cannabis sativa and is the most commonly used illegal drug in the United States. While normally smoked, marijuana can be eaten. Smoking marijuana irritates the lungs as the smoke contains more cancer-causing chemicals than tobacco smoke. Marijuana is often the first illegal drug used and usage runs the risk for progressing to more dangerous drugs like heroin and cocaine.

Cocaine (also known as “crack,” “coke,” and “blow”) is derived from the cocoa plant of South America and can be smoked, snorted, swallowed or injected. The effects and intensity of the high depend on upon the manner in which it is taken. Short and long-term usage of cocaine is associated with damage to the brain, heart, lungs, and kidneys.

Heroin (also known as “smack”) is a powerful drug that can cause pleasure, sleepiness, and slowed breathing. Withdrawal from heroin is intense and can cause gastrointestinal problems, confusion, and sweating. As heroin is usually injected – often with unclean needles – heroin can cause health conditions such as damage to the heart valves, HIV/AIDS infections, botulism, and tetanus.

Methamphetamines (also known as “meth,” “speed, “crystal meth”) is a powerful stimulant that is becoming increasingly common on the streets. Methamphetamines can be injected, snorted, smoked or eaten. The toxic effects of methamphetamine usage include heart attack, dangerously high blood pressure, paranoia, heart damage, loss of teeth, and strokes.

Effective treatment for and prevention of substance abuse has been difficult in previous years but through much research, today we have a far clearer picture of substance abuse treatment and prevention.


Substance abuse & addiction statistics

Worldwide, it’s estimated that five percent of the adult population, 230 million people – or one in twenty adults – used an illegal drug at least once in 2010. It’s estimated that 27 million people – or 0.6% of the world’s adult population – are considered to be problem drug users. Heroin, cocaine, and other drugs kill about 0.2 million people every year.

Co-Occurring Disorders

Substance abuse & addiction and co-occurring disorders

  • Depression
  • ADHD
  • Bipolar disorder
  • Post-traumatic stress disorder
  • Schizophrenia
  • Other substance use and abuse
  • Conduct disorder
  • Antisocial personality disorder
  • Eating disorders
  • Anxiety disorders
  • Other compulsive behaviors

Causes and Risk Factors

Causes and risk factors for substance abuse & addiction

People experiment with drugs for a variety of reasons. Curiosity, to have a good time, because friends are doing it, to increase intellectual or athletic abilities, or to ease other problems, like stress or anxiety. Drug abuse doesn’t always lead to addiction, but it’s important to note that drug abuse is less about the amount or frequency of abuse and more to do with the negative consequences of abuse, such as losing a job or your home.

As is the case with many drugs of abuse, there is no single cause for the development of drug addiction. Addiction is generally considered to be the combination of genetic, environmental, biological, and psychological factors working together

Many people begin to use and abuse illegal drugs during late childhood to the early teen years. There are a number of risk factors that can work together to cause someone to abuse drugs. This include:

GeneticsPeople who have a close relative or parent who has a problem with addiction to any substance or drug are more likely to develop a substance abuse problem later in life.

Biological: As all drugs of abuse are designed to promote pleasure feelings in the brain by affecting the brain’s dopamine levels, it has been postulated that some individuals who abuse drugs are doing so in order to attempt to regulate an inborn lack of dopamine in the brain.

Environmental: Children who grow up in a chaotic home environment in which parenting was ineffective are at greater risk for developing substance abuse problems. Especially notable causes are a lack of nurturing or attachment to a parent. Other environmental factors may include poor coping skills, poor academic performance, associating with a peer group who abuses substances, or feeling as though doing drugs is okay.

Psychological: Many individuals who abuse drugs have an underlying mental illness such as bipolar disorder, anxiety disorder, or depression. In order to manage the symptoms of the disorders, some individuals abuse drugs or alcohol to feel “normal.”

Signs and Symptoms

Signs and symptoms of substance abuse & addiction

Certain signs and symptoms of drug abuse will depend on upon the substance of abuse. Common symptoms of drug abuse include:


  • Aggressive, irritable behaviors
  • Violent mood swings
  • Changes in mood
  • Hopelessness
  • Depression
  • Suicidal ideations


  • Declining work performance or declining grades
  • Changes in behaviors
  • Acting selfishly and not caring about others
  • Getting high on drugs regularly
  • Lying, especially about the amount of drugs being used
  • Not caring about other people
  • Stealing money
  • Abusing drugs while driving
  • Avoiding friends and family to get high
  • Trouble with the law
  • Engaging in risky behaviors


  • Frequent hangovers from drug binges
  • Appearing rundown
  • Physical problems related to drug of abuse
  • Physical problems without a clear cause
  • Needing to use more drugs to get the same high
  • Mild tremors
  • Yellow skin or eyes
  • Increasing abdominal girth
  • Leg swelling
  • Persistent nagging cough
  • Fever
  • Chest pain
  • Pain at an injection site
  • Dark colored urine
  • Seizures
  • Strokes
  • Heart attack
  • Coma
  • Death


  • Forgetfulness
  • Paranoia
  • Problems with memory
  • Confusion
  • Aggression
  • Violence
  • Hallucinations
  • Delusions
  • Thoughts of harming yourself or others
  • Cravings
  • Psychosis


Effects of substance abuse & addiction

The effects of drug abuse will vary somewhat on the drug of abuse. Some common effects of substance abuse include:

  • Frequent trouble with the law
  • Unemployment
  • Divorce
  • Domestic violence
  • Problems with relationships
  • Difficulties staying employed or in school
  • Interpersonal problems
  • Liver disease
  • Hepatitis
  • Trauma
  • Cancer
  • Stroke
  • Heart attack
  • Seizures
  • Coma
  • Death

Withdrawl Symptoms

Withdrawl symptoms of substance abuse & addiction

The effects of withdrawal from drug abuse are very closely tied to the particular drug of abuse and the length of time in which a person is addicted to the drug. Withdrawing from a drug should occur under the direct supervision of a medical personnel. Some of the most common effects of withdrawal include:

  • Craving the drug
  • Social isolation
  • Poor concentration
  • Insomnia
  • Headaches
  • Seizures
  • Restlessness
  • Agitation
  • Anxiety
  • Depression
  • Difficulty breathing
  • Tremors
  • Sweating
  • Racing heart
  • Heart palpitations
  • Tightness in chest
  • Delirium tremens
  • Coma
  • Death