Class Typical Effects Overdose Effects







  • Increases the activity of gamma-aminobutyric acid (GABA)
  • By increasing an inhibitory neurotransmitter, alcohol dampens down neural firing
  • Also decreases the activity of glutamate, a major excitatory neurotransmitter
  • Person literally becomes less inhibited and feels euphoric
  • An initial upper phase from the release of inhibitions, followed by a downer phases as brain centres become increasingly depressed
  • A BAL increases, reaction time, eye-hand co-ordination and decision making are impaired
  • Seizures
  • alcohol poisoning inhibits brain function
  • coma




Barbiturates/ Tranquilizers

  • Barbiturates (sleeping pills)
  • Tranquilizers (Valium
  • Act as sedatives and relaxants
  • Highly addictive
  • Barbiturates trigger initial excitation, followed by slurred speech, loss of co-ordination, depression, sever memory impairment
  • Many people mistakenly regard Valium as harmless, user don’t often recognize they have become dependent until they try to stop and experience serious withdrawal symptoms
  • Withdrawal Effects: anxiety, insomnia, possible seizures, sudden withdrawal after heavy use can cause death
  • Overdose: disorientation, unconsciousness, coma and death


  • Powerful stimulant
  • Prescribed to reduce appetite and fatigue, decrease need for sleep, reduce depression
  • Increases dopamine and norepinephrine activity
  • Causes an inevitable crash because neuron’s norepinephrine and dopamine supplies have become depleted
  • Heart failure, cerebral hemorrhage (stroke), brain damage, schizophrenia-like hallucinations, paranoid delusions (called amphetamine psychosis)





  • Produces excitation, a sense of increases muscular strength and euphoria
  • Increases the activity of norepinephrine and dopamine by blocking their reuptake
  • Novacaine, a synthetic form of cocaine is still used in dentistry as an anaesthetic
  • Crack is chemically converted form, effects are much faster and intense
  • Fever, vomiting, convulsions, hallucinations, paranoid delusions, death from cardio respiratory arrest




Ecstasy (MDMA)

  • Alters serotonin functioning by causing the release of serotonin and blocking the reuptake
  • Once considered a safe drug for enhancing awareness of emotions and sensations
  • Produces acute and reversible cognitive deficits and long-term cognitive impairment, especially on language tasks
  • Causes deficits in memory and attention, causes sleep disturbances, sexual dysfunction and impaired immune responses
  • MDMA is a neurotoxin, damages neurons as it acts like a poison


Crystal Meth

  • Increases heart rate and blood pressure
  • Causes irritability, insomnia, loss of REM sleep, hyperactivity, confusion, hallucinations, anxiety, paranoia, and increased aggression
  • Stroke, heart attack, hypothermia, convulsions, death
  • Long-term use leads to heart, liver, kidney and lung damage




  • Provide pain relief, cause mood changes, which may include intense euphoria
  • Bind to and stimulate receptors normally activated by endorphins, and increase dopamine activity
  • Reduce a person’s breathing rate, possible coma, death


  • Feel an intense pleasurable “rush” within several minutes of an injection
  • Users feel peaceful and non-aggressive


Sold under several names such os OxyContin and Percocet

Powerful pain killer and a widely abused drug for its mood-altering effects








Distort or intensify sensory experience and can blur the boundaries between realityand fantasy

May cause violent outbursts, experience paranoia and panic and have flashbacks after the trip has ended

Causes a flooding of excitation in the nervous system

A dose of pure LSD no longer than the tip of a pin can affect a user for up to 8-16 hours

Decreases serotonin

Mescaline Comes from the peyote cactus
Psilocybin Magic mushrooms



Product of hemp plant and in its own category

THC is active ingredient, bind to receptors on neurons throughout the brain

Brain produces THC-like substances, called cannabinoids

High doses can cause negative changes in mood, sensory distortions and feelings of pain and anxiety, impairs reaction time, thinking, memory and learning

Fatigue, anxiety, disorientation, sleep disruptions, irritiability, nausea and vomitting

author avatar
William Anderson (Schoolworkhelper Editorial Team)
William completed his Bachelor of Science and Master of Arts in 2013. He current serves as a lecturer, tutor and freelance writer. In his spare time, he enjoys reading, walking his dog and parasailing. Article last reviewed: 2022 | St. Rosemary Institution © 2010-2024 | Creative Commons 4.0

Leave a Reply

Your email address will not be published. Required fields are marked *

Post comment