Why does the sap of the poppy plant, opium, effect the human brain!?
The human brain has natural pain killers, called endogenous opioids, or natural endorphins already in it. They are in the reward center of the brain. Opium fits on the same receptor as endogenous opioids because they have a similar chemical structure. The reward center of the brain is activated by pain and stress or when we complete a necessary activity for our survival. When we are hurt, stressed, exercise, eat a good meal, have sexual experiences, feel love, etcetera our body produces natural endorphins. When released, endorphins fill the space between nerve cells, preventing them from communicating a pain signal. This gives relief from pain.
Man-made or synthetic opiates are so addictive because they produce a result stronger than natural opiates. When a person experiences this artificial rush nothing else compares to it. The brain recognizes their drug of choice as the most important thing in their life and necessary for their survival. Therefore, people with severe addiction find themselves homeless, with lost relationships, having neglected their health and nutrition and have little interest in sex. All the hierarchy of needs necessary for survival are hijacked and redirected towards drug use.
The poppy plant is medicinal. Nature often provides medicines of benefit to humans. The purpose of the poppy plant is to provide pain management for end of life care, cancer and other instances of extreme pain. The problem is when people misuse the plant and develop artificial substitutes for it like Fentanyl. Oftentimes, people who begin taking opioids for pain realize that it also helps with their anxiety and depression. For this reason, people particularly vulnerable to opioid addiction, are people with emotional pain or trauma. When they first begin using opioids, they feel relief from their symptoms and continue to seek it out to self-medicate. Once they have progressed to physical addiction, they notice all the damaging effects their use is having in their life but cannot stop. They frequently report feeling controlled and trapped.
When the body is addicted to opioids it has developed a tolerance to the drug and needs a larger amount to feel the same effect. If a person tries to stop using, they will feel their problematic symptoms resurge with a vengeance. They will experience not only uncomfortable physical withdrawals but psychological symptoms of anxiety, depression, and desperation. This generally does not happen with natural endorphins because they do not have as strong an effect on the brain. However, people can become addicted to the natural rush produced by sex, gambling, food, etcetera. Basically, any substance or activity which produces pleasurable feelings is sought to be repeated and can become a problematic behavior.