How Opioids Change the Brain

The way you feel when you take opioids is entirely due to the effects they have on your brain and central nervous system. When someone takes opioids, whether it’s prescription painkillers or heroin, they initially get a tremendous rush of pleasure or elation from it.

Before looking at the specifics of how opioids change the brain, it’s valuable to cover the effect they have on the brain even when they’re taken for the first time.

How Opiates Change the Brain
How opioids change the brain has a lot to do with why you feel euphoric when you first take them.

Opioids are a type of medicine that is intended to relieve pain when they’re given in the prescription form. Along with prescription painkillers like Vicodin, opioids also include the illegal drug heroin. Other commonly used opioids include morphine and codeine.

The human brain makes its own small levels of opioids which bind to the opioid receptors found in the brain, the spine and throughout the central nervous system.

However, when someone takes opioids, the effect is hundreds of times stronger. When someone takes heroin or a prescription painkiller, they’re flooded with a rush of dopamine, which is a naturally-occurring chemical.

There’s an intense sense of euphoria that’s stronger than what any person could experience on their own without the introduction of opioids. Other effects of taking opioids include pain, creating a calming feeling and slowing the respiratory system. Often people may feel nausea or the need to vomit when they first take opioids because of the way they interact with the brain.

Your brain is wired to want to keep repeating activities that brought it pleasure. That’s why when you take opioids and experience a high or sense of pleasure from them, your brain remembers it and the reward circuits want you to continue doing that again and again. This occurrence is what leads to addiction to drugs.

Regarding long-term changes in the brain: when someone takes opioids, the brain’s reward circuit starts to, in a sense, rewire itself. This change makes it harder for someone who’s used opioids, particularly for a long period, to then feel pleasure or reward on their own without the use of the drug.

Opioids also change the brain because the brain stops reacting to the drugs. With opioids, this can happen quickly. It’s as if the presence of the opioids become the new normal to the brain. When that transformation happens, that is a sign that the person is building a tolerance to the drug. Tolerance is what leads to a physical dependence on opioids, and addiction in many cases.

There has also been research on how opioids change the brain that shows long-term abuse of these drugs can completely alter the parts of the brain that respond to stress and handle motivation. Some areas of the brain in long-term opioid abusers showed signs of shrinking or going dark, and others also demonstrated changes in the level of certain chemicals that then change how they respond to various stimuli.

When someone’s brain changes from opioids, they will often have strong cravings for drugs when they experience emotional or physical distress, see things they associate with drugs or when they’re near drugs or have access to them. That rewiring of the brain that comes with long-term opioid use is why it can be so difficult to stop using these drugs.

How opioids affect the brain can also be related to short-term use. For example, research has shown that in as little as a month of using morphine, the human brain underwent neuroplastic changes. There were changes in volume and a reduction in gray matter. There was also shifts in the amygdala, which relates to reward-based learning and associative learning, as well as reinforcement and dependence.

As a result of the increasing research on how opioids change the brain, doctors and scientists are seeing that using opioids, even for a very short period, has the potential to change long-term behavioral patterns, even after the pleasure that comes from using the drug has diminished. That’s what creates the potential to misuse and become addicted to opioids.