Drug Tolerance and Classical Conditioning

Prescription and illegal drugs have addictive properties to them, but our bodies’ natural response to these drugs cause us to become resistant to them, causing us to need higher doses. As drugs enter our bodies, our body responds by trying to bring itself back to homeostasis, the state in which our body is most natural or most balanced. Part of the reason as to why the effect of drugs starts to weaken can be explained by classical conditioning and the environment in which drugs are taken. Controlled drugs such as morphine, an opiate that is usually administered by a doctor, can be just as deadly as a ‘street’ drug such as heroin, another opiate derived from morphine.

Our bodies have a natural balanced state it tries to keep itself in known as homeostasis. This includes body temperature, fluid balances, and chemical balances. When an unwanted chemical, like a drug for example, enters the human body – it tries to counteract the drug by bringing itself back to homeostasis. The first few times the drug is administered the effect may be just as strong, but as the drugs gets introduced more and more into the body, our minds begin to prepare itself when the drugs are going to be taken and will try to counteract it as the drugs enter our body. This tolerance is due to factors like dosage amount and the number of times the drug has been taken but there is also another reason as to why a tolerance begins to build starting with out minds.

This is where classical conditioning comes in. With the drug as an unconditioned stimulus, the effect of the drug as the conditioned response, and an environmental cue as the conditioned stimulus; classical conditioning can explain how and why a tolerance to a drug begins to appear. In one case, a man took morphine in his bedroom for a month. As time went by, he needed higher-level prescriptions because he started to become tolerant to the morphine. When he decided to take the morphine in his living room, he died. Here, his bedroom was the environmental cue and conditioned stimulus. When he took the morphine in a separate environment from where he had been taking it normally, his mind did not prepare his body for the morphine he was about to take. This means that his tolerance for the morphine was no longer there. Keep in mind, he was already taking the higher-level morphine doses, but it was not until he was in a different environment that he died from it. Similarly, dogs who were injected with adrenaline began to show signs of bradycardia (slowed heart action) to counteract the adrenaline when the dogs would see the injection stand where they were normally injected.

The unconditioned stimulus, the drug, and the conditioned stimulus, the environment, form a relationship in the brain. When the person taking the drug enters the environment in which they are accustomed to take the drug, the body responds by preparing itself to counteract the drug. Over time, the drug no longer produces the effect needed because of the tolerance that is built up, meaning that higher dosages of drugs are needed to produce the wanted/needed effect. Even when taking these higher dosages of the drugs, the body can still handle the effects and dosage because of the tolerance it has built up. BUT, when the person takes the drug in an unfamiliar environment, the brain no longer is receiving the conditioned stimulus that it would once receive with the unconditioned stimulus. Because of this, the mind no longer counteracts the effect of the drugs, leading to complications with the dosage. Now that the brain has little to no tolerance to the drug in the new environment, the body receives the full effect of the dosage that they are taking which can lead to serious and lethal consequences.

The evidence does not stop here. Looking back on cases of heroin ‘overdose’, there have been similar details about the deaths of the individuals. Firstly, most had already been taking the dosage in which they had taken when they died for quite some time. Secondly, most that died took the drug in an unfamiliar environment where they had previously not been accustomed to taking the drug. Though the dosage of the heroin did kill them, it was because their bodies did not prepare itself to counteract the drug because they were in an unfamiliar environment. Hence proving that a relationship with drug tolerance and classical conditioning exists.

With all this evidence, it is easy to see why it is now widely accepted to relate drug tolerance, drug overdoses, and classical conditioning together. Though our bodies become tolerant over time, it is because the association between the environment and the drug that cause us to have stronger tolerances and a need for stronger dosages.