Drug addiction symptoms or behaviors include, among others:

• Feeling that you have to use the drug regularly — daily or even several times a day
• Having intense urges for the drug that block out any other thoughts
• Over time, needing more of the drug to get the same effect
• Taking larger amounts of the drug over a longer period of time than you intended
• Making certain that you maintain a supply of the drug
• Spending money on the drug, even though you can't afford it
• Not meeting obligations and work responsibilities, or cutting back on social or recreational activities because of drug use
• Continuing to use the drug, even though you know it's causing problems in your life or causing you physical or psychological harm
• Doing things to get the drug that you normally wouldn't do, such as stealing
• Driving or doing other risky activities when you're under the influence of the drug
• Spending a good deal of time getting the drug, using the drug or recovering from the effects of the drug
• Failing in your attempts to stop using the drug
• Experiencing withdrawal symptoms when you attempt to stop taking the drug

Recognizing unhealthy drug use in family members

Sometimes it's difficult to distinguish normal teenage moodiness or angst from signs of drug use. Possible indications that your teenager or other family member is using drugs include:

• Problems at school or work  - frequently missing school or work, a sudden disinterest in school activities or work, or a drop in grades or work performance
• Physical health issues  - lack of energy and motivation, weight loss or gain, or red eyes
• Neglected appearance  - lack of interest in clothing, grooming or looks
• Changes in behavior  - exaggerated efforts to bar family members from entering his or her room or being secretive about where he or she goes with friends; or drastic changes in behavior and in relationships with family and friends
• Money issues  - sudden requests for money without a reasonable explanation; or your discovery that money is missing or has been stolen or that items have disappeared from your home, indicating maybe they're being sold to support drug use

Recognizing signs of drug use or intoxication

Signs and symptoms of drug use or intoxication may vary, depending on the type of drug. Below you'll find several examples.

Marijuana, hashish and other cannabis-containing substances

People use cannabis by smoking, eating or inhaling a vaporized form of the drug. Cannabis often precedes or is used along with other substances, such as alcohol or illegal drugs, and is often the first drug tried.

Signs and symptoms of recent use can include:

• A sense of euphoria or feeling "high"
• A heightened sense of visual, auditory and taste perception
• Increased blood pressure and heart rate
• Red eyes
• Dry mouth
• Decreased coordination
• Difficulty concentrating or remembering
• Slowed reaction time
• Anxiety or paranoid thinking
• Cannabis odor on clothes or yellow fingertips
• Exaggerated cravings for certain foods at unusual times

Long-term (chronic) use is often associated with:

• Decreased mental sharpness
• Poor performance at school or at work
• Reduced number of friends and interests

K2, Spice and bath salts

Two groups of synthetic drugs — synthetic cannabinoids and substituted or synthetic cathinones — are illegal in most states. The effects of these drugs can be dangerous and unpredictable, as there is no quality control and some ingredients may not be known.

Synthetic cannabinoids, also called K2 or Spice, are sprayed on dried herbs and then smoked, but can be prepared as an herbal tea. Despite manufacturer claims, these are chemical compounds rather than "natural" or harmless products. These drugs can produce a "high" similar to marijuana and have become a popular but dangerous alternative.

Signs and symptoms of recent use can include:

• A sense of euphoria or feeling "high"
• Elevated mood
• An altered sense of visual, auditory and taste perception
• Extreme anxiety or agitation
• Paranoia
• Hallucinations
• Increased heart rate and blood pressure or heart attack
• Vomiting
• Confusion

Substituted cathinones, also called "bath salts," are mind-altering (psychoactive) substances similar to amphetamines such as ecstasy (MDMA) and cocaine. Packages are often labeled as other products to avoid detection.

Despite the name, these are not bath products such as Epsom salts. Substituted cathinones can be eaten, snorted, inhaled or injected and are highly addictive. These drugs can cause severe intoxication, which results in dangerous health effects or even death.

Signs and symptoms of recent use can include:

• Euphoria
• Increased sociability
• Increased energy and agitation
• Increased sex drive
• Increased heart rate and blood pressure
• Problems thinking clearly
• Loss of muscle control
• Paranoia
• Panic attacks
• Hallucinations
• Delirium
• Psychotic and violent behavior

Barbiturates, benzodiazepines and hypnotics

Barbiturates, benzodiazepines and hypnotics are prescription central nervous system depressants. They're often used and misused in search for a sense of relaxation or a desire to "switch off" or forget stress-related thoughts or feelings.

• Barbiturates :  Examples include phenobarbital and secobarbital (Seconal).
• Benzodiazepines :  Examples include sedatives, such as diazepam (Valium), alprazolam (Xanax), lorazepam (Ativan), clonazepam (Klonopin) and chlordiazepoxide (Librium).
• Hypnotics :  Examples include prescription sleeping medications such as zolpidem (Ambien, Intermezzo, others) and zaleplon (Sonata).

Signs and symptoms of recent use can include:

• Drowsiness
• Slurred speech
• Lack of coordination
• Irritability or changes in mood
• Problems concentrating or thinking clearly
• Memory problems
• Involuntary eye movements
• Lack of inhibition
• Slowed breathing and reduced blood pressure
• Falls or accidents
• Dizziness

Meth, cocaine and other stimulants

Stimulants include amphetamines, meth (methamphetamine), cocaine, methylphenidate (Ritalin, Concerta, others) and amphetamine-dextroamphetamine (Adderall, Adderall XR, others). They are often used and misused in search of a "high," or to boost energy, to improve performance at work or school, or to lose weight or control appetite.

Signs and symptoms of recent use can include:

• Feeling of exhilaration and excess confidence
• Increased alertness
• Increased energy and restlessness
• Behavior changes or aggression
• Rapid or rambling speech
• Dilated pupils
• Confusion, delusions and hallucinations
• Irritability, anxiety or paranoia
• Changes in heart rate, blood pressure and body temperature
• Nausea or vomiting with weight loss
• Impaired judgment
• Nasal congestion and damage to the mucous membrane of the nose (if snorting drugs)
• Mouth sores, gum disease and tooth decay from smoking drugs ("meth mouth")
• Insomnia
• Depression as the drug wears off

Club drugs

Club drugs are commonly used at clubs, concerts and parties. Examples include ecstasy or molly (MDMA), gamma-hydroxybutyric acid (GHB), flunitrazepam (Rohypnol ― a brand used outside the U.S. ― also called roofie) and ketamine. These drugs are not all in the same category, but they share some similar effects and dangers, including long-term harmful effects.

Because GHB and flunitrazepam can cause sedation, muscle relaxation, confusion and memory loss, the potential for sexual misconduct or sexual assault is associated with the use of these drugs.

Signs and symptoms of use of club drugs can include:

• Hallucinations
• Paranoia
• Dilated pupils
• Chills and sweating
• Involuntary shaking (tremors)
• Behavior changes
• Muscle cramping and teeth clenching
• Muscle relaxation, poor coordination or problems moving
• Reduced inhibitions
• Heightened or altered sense of sight, sound and taste
• Poor judgment
• Memory problems or loss of memory
• Reduced consciousness
• Increased or decreased heart rate and blood pressure

Hallucinogens

Use of hallucinogens can produce different signs and symptoms, depending on the drug. The most common hallucinogens are lysergic acid diethylamide (LSD) and phencyclidine (PCP).

LSD use may cause:

• Hallucinations
• Greatly reduced perception of reality, for example, interpreting input from one of your senses as another, such as hearing colors
• Impulsive behavior
• Rapid shifts in emotions
• Permanent mental changes in perception
• Rapid heart rate and high blood pressure
• Tremors
• Flashbacks, a re-experience of the hallucinations — even years later

PCP use may cause:

• A feeling of being separated from your body and surroundings
• Hallucinations
• Problems with coordination and movement
• Aggressive, possibly violent behavior
• Involuntary eye movements
• Lack of pain sensation
• Increase in blood pressure and heart rate
• Problems with thinking and memory
• Problems speaking
• Impaired judgment
• Intolerance to loud noise
• Sometimes seizures or coma

Inhalants

Signs and symptoms of inhalant use vary, depending on the substance. Some commonly inhaled substances include glue, paint thinners, correction fluid, felt tip marker fluid, gasoline, cleaning fluids and household aerosol products. Due to the toxic nature of these substances, users may develop brain damage or sudden death.

Signs and symptoms of use can include:

• Possessing an inhalant substance without a reasonable explanation
• Brief euphoria or intoxication
• Decreased inhibition
• Combativeness or belligerence
• Dizziness
• Nausea or vomiting
• Involuntary eye movements
• Appearing intoxicated with slurred speech, slow movements and poor coordination
• Irregular heartbeats
• Tremors
• Lingering odor of inhalant material
• Rash around the nose and mouth

Opioid painkillers

Opioids are narcotic, painkilling drugs produced from opium or made synthetically. This class of drugs includes, among others, heroin, morphine, codeine, methadone and oxycodone.

Sometimes called the "opioid epidemic," addiction to opioid prescription pain medications has reached an alarming rate across the United States. Some people who've been using opioids over a long period of time may need physician-prescribed temporary or long-term drug substitution during treatment.

Signs and symptoms of narcotic use and dependence can include:

• Reduced sense of pain
• Agitation, drowsiness or sedation
• Slurred speech
• Problems with attention and memory
• Constricted pupils
• Lack of awareness or inattention to surrounding people and things
• Problems with coordination
• Depression
• Confusion
• Constipation
• Runny nose or nose sores (if snorting drugs)
• Needle marks (if injecting drugs)

Staging an intervention

People struggling with addiction usually deny that their drug use is problematic and are reluctant to seek treatment. An intervention presents a loved one with a structured opportunity to make changes before things get even worse and can motivate someone to seek or accept help.

An intervention should be carefully planned and may be done by family and friends in consultation with a doctor or professional such as a licensed alcohol and drug counselor, or directed by an intervention professional. It involves family and friends and sometimes co-workers, clergy or others who care about the person struggling with addiction.

During the intervention, these people gather together to have a direct, heart-to-heart conversation with the person about the consequences of addiction and ask him or her to accept treatment.

Like many mental health disorders, several factors may contribute to development of drug addiction. The main factors are:

• Environment. Environmental factors, including your family's beliefs and attitudes and exposure to a peer group that encourages drug use, seem to play a role in initial drug use.
• Genetics. Once you've started using a drug, the development into addiction may be influenced by inherited (genetic) traits, which may delay or speed up the disease progression.

Changes in the brain

Physical addiction appears to occur when repeated use of a drug changes the way your brain feels pleasure. The addicting drug causes physical changes to some nerve cells (neurons) in your brain. Neurons use chemicals called neurotransmitters to communicate. These changes can remain long after you stop using the drug.

People of any age, sex or economic status can become addicted to a drug. Certain factors can affect the likelihood and speed of developing an addiction:

• Family history of addiction :  Drug addiction is more common in some families and likely involves genetic predisposition. If you have a blood relative, such as a parent or sibling, with alcohol or drug addiction, you're at greater risk of developing a drug addiction.
• Mental health disorder :  If you have a mental health disorder such as depression, attention-deficit/hyperactivity disorder (ADHD) or post-traumatic stress disorder, you're more likely to become addicted to drugs. Using drugs can become a way of coping with painful feelings, such as anxiety, depression and loneliness, and can make these problems even worse.
• Peer pressure :  Peer pressure is a strong factor in starting to use and misuse drugs, particularly for young people.
• Lack of family involvement :  Difficult family situations or lack of a bond with your parents or siblings may increase the risk of addiction, as can a lack of parental supervision.
• Early use :  Using drugs at an early age can cause changes in the developing brain and increase the likelihood of progressing to drug addiction.
• Taking a highly addictive drug :  Some drugs, such as stimulants, cocaine or opioid painkillers, may result in faster development of addiction than other drugs. Smoking or injecting drugs can increase the potential for addiction. Taking drugs considered less addicting — so-called "light drugs" — can start you on a pathway of drug use and addiction.

Drug use can have significant and damaging short-term and long-term effects. Taking some drugs can be particularly risky, especially if you take high doses or combine them with other drugs or alcohol. Here are some examples.

• Methamphetamine, opiates and cocaine are highly addictive and cause multiple short-term and long-term health consequences, including psychotic behavior, seizures or death due to overdose.
• GHB and flunitrazepam may cause sedation, confusion and memory loss. These so-called "date rape drugs" are known to impair the ability to resist unwanted contact and recollection of the event. At high doses, they can cause seizures, coma and death. The danger increases when these drugs are taken with alcohol.
• Ecstasy or molly (MDMA) can cause dehydration, electrolyte imbalance and complications that can include seizures. Long-term, MDMA can damage the brain.
• One particular danger of club drugs is that the liquid, pill or powder forms of these drugs available on the street often contain unknown substances that can be harmful, including other illegally manufactured or pharmaceutical drugs.
• Due to the toxic nature of inhalants, users may develop brain damage of different levels of severity.

Other life-changing complications

Dependence on drugs can create a number of dangerous and damaging complications, including:

• Getting a communicable disease. People who are addicted to a drug are more likely to get an infectious disease, such as HIV, either through unsafe sex or by sharing needles.
• Other health problems. Drug addiction can lead to a range of both short-term and long-term mental and physical health problems. These depend on what drug is taken.
• Accidents. People who are addicted to drugs are more likely to drive or do other dangerous activities while under the influence.
• Suicide. People who are addicted to drugs die by suicide more often than people who aren't addicted.
• Family problems. Behavioral changes may cause marital or family conflict and custody issues.
• Work issues. Drug use can cause declining performance at work, absenteeism and eventual loss of employment.
• Problems at school. Drug use can negatively affect academic performance and motivation to excel in school.
• Legal issues. Legal problems are common for drug users and can stem from buying or possessing illegal drugs, stealing to support the drug addiction, driving while under the influence of drugs or alcohol, or disputes over child custody.
• Financial problems. Spending money to support drug use takes away money from other needs, could lead to debt, and can lead to illegal or unethical behaviors.