According to a 2009 study of Ontario students by the Centre for Addiction and Mental Health, the most commonly used drug is alcohol (58.2 per cent of students reported drinking in the past year), the second is weed (25.6 per cent had used it in the past year) and the non-medical use of prescription opoid pain relievers such as Oxycodone ranked third (with 17.8 per cent reporting use in the past year). Just over one-fifth of students reported using at least one prescription drug non-medically over the past year. Past year use of hallucinogens like magic mushrooms was reported by 5 to 7 per cent of students.

We're not here to tell you whether you should take drugs or not; you can make that choice on your own. But it is important that you know the short- and long-term effects of what you're putting in your body.

Alcohol

What it is
Alcohol is a depressant that is consumed as a beverage. Approximately 80 per cent of the alcohol in a beverage is absorbed in the small intestines and the remaining 20 per cent that is absorbed in the stomach. The speed at which the alcohol is absorbed depends on the amount of alcohol consumed, whether the consumer's stomach is empty or full, and the type of drink.

Short-term effects
- Slows breathing and heart rate
- Lowered inhibitions, which may lead to risky behaviour
- Poor coordination, slurred speech
- Blackouts and memory loss
- Nausea or vomiting, caused by distortion of the person's sense of balance or by the body's attempt to rid itself of the alcohol
- Stupor at a blood alcohol concentration of 0.40, which may include disorientation, confusion, severely impaired brain and muscular function
- Coma when the BAC reaches a level of 0.50, with a high risk of respiratory failure and death
- Hangovers and headaches

Long-term effects
- Irritation of the stomach lining, which can be painful and is potentially fatal
- Tissue damage to the liver and pancreas
- Alcohol abuse can lead to "fatty liver" — fatty degeneration in the liver, which can cause nausea and vomiting, lack of appetite, weight loss and fever
- Brain damage, which can lead to dementia, difficulties with coordination and motor control, and loss of feeling or painful burning in the feet
- Diabetes
- Obesity
- Increased risk of liver, throat, breast and other cancers
- Alcohol dependence can result in clinical depression
- Mothers who drink alcohol during pregnancy may give birth to infants with fetal alcohol syndrome, which can include mental retardation and irreversible physical deformities

Marijuana

What it is
Marijuana is an herb that can be smoked or baked into food. It contains chemicals called cannabinoids; the best known is called tetrahydrocannabinol (THC). The high caused by smoking marijuana is mainly due to THC.

Short-term effects
- Stimulates appetite and suppresses nausea
- Lowers pressure in the eye and is sometimes used to treat glaucoma
- Reduces muscle spasms in people with nerve problems
- Sometimes used as a treatment to reduce pain
- Can disrupt balance, physical coordination and visual perception, making it dangerous to drive while high

Long-term effects
- Linked to some of the same health issues as smoking tobacco, such as bronchitis, but has not clearly been linked to lung cancer
- Memory loss after prolonged periods of smoking marijuana, and the more a user smokes, the longer it takes to get his or her memory back to normal
- Psychological dependence gains strength over time, users smoke increasingly large quantities of marijuana in order to get the same feelings they did when they first started
- Impaired coordination, balance, reflexes and physical performance — will improve after quitting smoking
- Hallucinations, psychosis
- Impaired ability to learn, functioning at a lower intellectual level
- Depression
- People who are prone to mental illness increase their risk of developing full-blown mental illness with heavy use
- Anxiety, panic attacks, feelings of discomfort

Oxycodone

What it is
Often sold under the brand name OxyContin, it is an opiate prescribed for moderate to severe pain. It is given in pill form, and is a slow-acting pain reliever. Some users crush and snort the pills, leading to a high that is reported to be more intense than that of heroin.

Short-term effects
- Reduced physical pain and muscle weakness
- Severe itching
- Nausea and constipation
- Depresses the central nervous system, which can lead to strange behaviour, lightheadedness, mental clouding, confusion, sleepiness or mood swings
- Dramatically slows breathing; if a person breathes fewer than 10 times per minute, he or she is at risk for permanent brain damage

Long-term effects
- Malnutrition and weight loss
- Arthritis and other rheumatologic problems
- Collapsed veins from intravenous use
- Liver and/or kidney disease
- Decreased levels of testosterone, which may result in impotence or enlargement of the prostate
- Changes brain chemistry and makes the brain think it needs the drug function normally
- Users can build up a tolerance to oxycodone, leading them to ingest more to produce the same high as when they first started using

Ritalin and Adderall

What it is
These are two of the most popular drugs prescribed by doctors as a stimulant treatment for ADHD. They are both used illicitly for their energy-inducing effects, and both have a high propensity for misuse, abuse and dependence. Snorting either of these drugs in powder form increases the intensity of the high because the drugs enter the bloodstream directly.

Short-term effects
- Increased attentiveness and focus
- Increased energy, a sense of well-being and comfort
- Can enhance the effects of other drugs, such as ecstasy
- Because these drugs are similar in chemical makeup to methamphetamine, they may have similar effects, including sleep disturbance, irregular heartbeat or increased heart rate and circulation problems
- Sweating, nausea and headache
- Agitation and anxiety, as well as irritability, depression or restlessness
- Bouts of aggression or hostility
- Psychotic episodes
- In cases of overdose, users may experience tremors and hallucinations

Long-term effects
- Weight loss due to aversion to food while high
- May cause developmental problems in the brain and changes in brain wave activity
- Destruction of the nasal and sinus cavities and lung tissue from snorting
- Chronic anxiety
- Symptoms similar to paranoia

Magic Mushrooms

What it is
Psilocybin mushrooms, also called 'shrooms' or 'magic mushrooms,' are a hallucinogen that are either eaten in their dried mushroom form, consumed as a white powder or brewed into a tea. They cause users to experience a distorted version of reality, also called 'tripping.' Shrooms are generally not considered addictive, but users may develop a tolerance for their effects, leading to using increased dosages.

Short-term effects
- Nausea and jitteriness
- Slightly elevated blood pressure, heart rate, and breathing
- Increased body temperature
- Dehydration
- Heightened emotions and distorted senses of touch, sight, sound and taste
- Some feelings of being out of control of thoughts
- Effects largely depend on the user's mood, so if a user feels anxiety or fear, it could lead to a bad trip
- Pre-existing mental health issues, such as depression, schizophrenia or paranoia, may cause unpredictable reactions

Long-term effects
- According to Health Canada, the effects of long-term psilocybin use have not been studied
- Some users have experienced prolonged psychosis — loss of touch with reality — that resembles paranoid schizophrenia
- Some users experience memory impairment and flashbacks

For more information, visit goaskalice.columbia.edu. Another excellent resource is Buzzed: The Straight Facts about the Most Used and Abused Drugs from Alcohol to Ecstasy, by Cynthia Kuhn, Scott Swartzwelder, and Wilkie Wilson.