Say No to drugs

A puff of this, and the world transforms into a colourful kaleidoscope of dancing patterns and waves of sound; a sip of that, and the muscles in your body relax like jelly.

We know different drugs make us experience the world around us in very different ways - and their after-effects are often nowhere near as pleasant as the immediate results they produce. So what exactly are these drugs doing to the brain to prompt these feelings?

When marijuana's active ingredient, THC, hits the brain , it causes brain cells to release the feel-good chemical dopamine. Dopamine is a part of the brain's reward system - it's the same chemical that makes us feel good when we do enjoyable things such as eating and having sex.
When overexcited by drugs, the reward system creates feelings of euphoria. This is also why, in some rare cases, excessive use can be a problem: The more often you trigger that euphoria, the less you may feel for other rewarding experiences.

Like other drugs, booze affects brain chemistry by altering the levels of neurotransmitters , the chemical messengers that pass along the signals that control our thinking and behavior.
Alcohol slows down our thinking , breathing, and heart rate by halting our 'excitatory' messengers, the ones that typically increase our energy levels. But it amplifies our 'inhibitory' messengers, those that usually work to calm things down. It also boosts our brain's feel-good dopamine levels.

The brain converts heroin into morphine , which binds to molecules on cells in the brain and body called opioid receptors that affect how we perceive pain and rewards. This explains the surging sense of euphoria that many people feel when they inject the drug.
Because we also have opioid receptors in our brain stem, the body's main control centre, overdosing on heroin can slow and even stop breathing, leading to brain damage, coma, or death.

Recent research has shed light on a troubling potential link between heroin and opiate painkillers such as Vicodin and OxyContin. A CDC report released in July found that people who abused opiates were 40 times as likely to abuse heroin. One of the reasons abusing opiates may make people more susceptible to future heroin abuse, the report says, is that the drugs act similarly in the brain.

Caffeine is the most commonly used psychoactive drug in the world . A stimulant of the central nervous system , caffeine can give us a temporary mood boost. But this can also pump up our adrenaline levels, which primes us for exercise but can leave us more irritable and anxious .
Caffeine also keeps us alert by mimicking a molecule called adenosine in the brain and
hijacking one aspect of a complex process our brains use to put us to bed at night.

Whether it's snorted, smoked, or injected, cocaine enters the bloodstream and penetrates the brain in a matter of seconds. Once there, it causes an intense feeling of euphoria - its characteristic 'high' - by overwhelming the mind with the feel-good chemical dopamine. The sensation of pleasure is so powerful that some lab animals, when given a choice, will choose cocaine over food until they starve to death.
One part of the brain most acutely affected by cocaine includes key memory centres , which may partially explain some of its addictive properties. In mice that have been dosed repeatedly with cocaine, a host of changes occur in the brain cells in a region that helps with decision-making and inhibition. The more often they get the drug, the more likely they are to access it again when given the chance.

Say NO to drugs