A test regarding a supportive environment for different rats that are given addiction. I have used this observation in a very applicable form. This writing highlights possible reasons this may not have worked before in actuality and why it should likely work effectively now (ie getting our loved ones home and using drugs and kratom as a therapy to sobriety, in connection with treatment and rehabilitation).
Scientists adhering to the disease model believe that behavior is “the business of the brain,” according to Avram Goldstein, Professor Emeritus of Pharmacology at Stanford University, and a leading researcher into drug addiction. Goldstein writes that the site of action of heroin and all other addictive drugs is a bundle of neurons deep in the brain called the mesolimbic dopaminergic pathway, a reward pathway that mediates feelings of wanting and motivation. Within this pathway, heroin causes dopamineneurons to release dopamine, a neurotransmitter that determines incentive salience and causes the user to want more. Dopamine neurons are normally held in check by inhibitory neurons, but heroin shuts these down, allowing the dopamine neurons to become overstimulated. The brain responds with feelings of euphoria, but the stimulation is excessive, and in order to protect itself against this, the brain adapts by becoming less sensitive to the heroin.
This has two consequences, according to the disease model. First, more heroin is required to produce the high, and at the same time, the reward pathway becomes less sensitive to the effects of endorphins, which regulate the release of dopamine, so that without heroin, there is a persistent feeling of sickness. After repeated intake, the user becomes tolerant and dependent, and undergoes withdrawal symptoms if the heroin supply is terminated. As the feelings of withdrawal worsen, the user loses control, writes Goldstein, and becomes an addict.
According to Alexander, the disease model makes either of two claims:
Claim A: All or most people who use heroin or cocaine beyond a certain minimum amount become addicted.
Claim B: No matter what proportion of the users of heroin and cocaine become addicted, their addiction is caused by exposure to the drug.
The caged rats (Groups CC and PC) took to the morphine instantly, even with relatively little sweetener, with the caged males drinking 19 times more morphine than the Rat Park males in one of the experimental conditions. But no matter how sweet the morphine became, the rats in Rat Park resisted it. They would try it occasionally — with the females trying it more often than the males — but invariably they showed a preference for the plain water. It was, writes Alexander, “a statistically significant finding.” He writes that the most interesting group was Group CP, the rats who were brought up in cages but moved to Rat Park before the experiment began. These animals rejected the morphine solution when it was stronger, but as it became sweeter and more dilute, they began to drink almost as much as the rats that had lived in cages throughout the experiment. They wanted the sweet water, he concluded, so long as it did not disrupt their normal social behavior. Even more significant, he writes, was that when he added a drug called Naloxone, which negates the effects of opioids, to the morphine-laced water, the Rat Park rats began to drink it.
Some further studies failed to reproduce the original experiment’s results, but in at least one of these studies both caged and “park” rats showed a decreased preference for morphine, suggesting a genetic difference. In any case, the publications did draw attention to the idea that the environment that laboratory animals live in might influence the outcome in experiments related to addiction.