this is Susan Susan loves to bike while out for a ride she falls and breaks her arms special cells called neurons send a signal through the spinal cord to the brain which interprets the signal as pain Susan understands the pain means she needs to go to the hospital and her body is equipped for survival helping her not to panic so she can seek help many of her neurons are covered in proteins called opioid receptors these receptors act like a brake to slow down the neurons ability to send pain signals when injured her body releases natural
painkillers called endorphins like a key in a lock endorphins activate opioid receptors slowing down the pain signal and preventing a panic Susan gets treated for the broken bone but three months later her arm still hurts and now that pain is making her feel depressed and anxious so her doctor prescribes an opioid painkiller there are many different opioids but they all share a chemical similarity to our own endorphins this allows them to bind to the same opioid receptors and stop pain signals but that's not all they do deep inside Susan's brain is a region called the
ventral tegmental area or VTA for short the VTA is full of neurons that produce a chemical called dopamine when something good happens dopamine is released giving Susan a feeling of pleasure this helps teach her brain to keep seeking out good things to keep dopamine neurons in check inhibitory thoughts keep the brakes on until something good comes along just like the payment days neurons are covered in opioid receptors when Susan takes the painkiller prescribed by her doctor the opioid receptors turn off the rush of dopamine temporarily eliminates Susan's depression and anxiety and she feels relief calmness
and even euphoria as Susan continues to take the painkillers her brain responds by trying to regain its balance her inhibitory neurons work extra hard even when the receptors are activated and it becomes harder and harder for her dopamine neurons to release dopamine Susan finds that she needs to increase her dose of painkillers in order to feel comfortable this is called tolerance eventually Susan's pills run out inhibitory neurons over her let loose clamping down on the dopamine neurons and shutting them out almost completely now not only is Susan in pain but the depression and anxiety come
back on top of that Susan feels ravaged by an inescapable physical sickness far worse than any flu Susan's body is going through withdrawal most people who take opioids for a long time tend to experience some withdrawal but they can still stop taking the pills and return to normal but for people like Susan it's not so easy for genetics in the environment she grew up in put her at a higher risk for addiction her withdrawal symptoms aren't just unpleasant they're unbearable Susan thinks the only way to feel normal is to find more opioids and this is
how the cycle of opioid addiction emerges driven by a brain trying to regain its balance but there is hope for Susan though the road to recovery can be challenging and there may be setbacks treatments can retrain Susan's brain with the help of medication and therapy Susan finds pleasure in her life once again [Music] you you [Music]
