A psychoactive drug is a chemical substance which, when consumed, can affect the brain and nervous system, resulting in an altered mental state. The potent effects of psychoactive drugs have led some to be used as prescription medicines, while others have become some of the most widely prohibited illicit substances in the world. So what are the effects of drugs on the brain? What are the different types of psychoactive drug, and how do these various chemicals affect behaviour, consciousness, mood, perception, and the functioning of the brain?
Depressants slow brain and nervous system functionShow moreShow less
Depressant drugs inhibit signals in the brain and nervous system, reducing neuronal messages and slowing the brain's activity down.
The category of opioids includes both opiates, which are psychoactive drugs derived from opium, and a range of synthetic and non-synthetic drugs with pain-relieving effects. Many pharmaceutical opioids were developed as alternatives to morphine, a highly addictive pain medication with many potential adverse effects. Opioids including morphine are effective as painkillers because they can activate mu and delta opioid receptors, which when activated can block pain signals sent through the nervous system to the brain.
Opioid receptors are abundant in areas of the brain where responses to psychoactive substances occur, including the dopamine reward pathway. Consequently, opioid use is both psychologically and biochemically addictive and can have a wide range of long-term effects on mental function, such changes to learning, reward, and stress responses.
[P1] Opioids work to block pain signals sent to the brain.