How Do Drugs Affect the Brain?

Most people take medicine during their lives, but how many of us understand how these substances actually work? In this topic, learn how drugs affect your brain.

Some drugs alter the communication between cells in the brain, and this affects our behavior in different ways. Different drugs have different effects – sometimes they even have different effects in different people!

The Biology of Drug Absorption

Before a drug can start taking effect, it has to go through the bloodstream. Depending on the drug in question and the method of administration, this journey through the bloodstream could last anywhere from a few seconds to a few hours. The slowest method of absorption is oral – typically by swallowing a pill. Injecting a drug into your bloodstream is much faster.

The “blood-brain barrier” keeps substances out of the brain that don’t belong there, and for a drug to reach the brain and begin working, it must contain a specific set of chemical compounds that will grant the drug access, like a key in a door, to the brain. At this point, the drug enters the brain and begins affecting its normal functionality by targeting nerves and synapses.

Neurons are brain cells. Synapses allow the exchange of electrochemical signals between neurons. These “signals” are called neurotransmitters. Generally, neurotransmitters work in one of two ways. They either inhibit receiving neurons – decreasing their activity, or they excite them – increasing activity. A drug’s effectiveness is determined by how much or how little it inhibits or accelerates these synaptic transmissions at different phases in the process of the drug releasing into your brain.

Common antidepressants stop the re-absorbing of serotonin, a neurotransmitter that modulates our moods. Energy, arousal, alertness, and pleasure can all be affected by how much or how little a drug inhibits or accelerates the absorption of serotonin.

Repeated Drug Use Can Be Dangerous

Repeated use of drugs can permanently rewire the brain’s internal “network” of cells. In the long term, this can damage a drug user’s ability to learn, remember things, and make decisions.

Even drugs for medicinal use can become dangerously addictive substances with unfortunate long-term consequences if they are abused. It’s important to carefully walk the fine line between legitimate medical use and drug abuse. Only take drugs when a doctor prescribes them, and don’t lie to your doctor to get drugs you don’t actually need!

Article for this topic by Daniel Martin.