Researchers from the University of Buffalo in New York may have discovered why relapse is so prevalent in heroin users despite honest attempts to abstain through the withdrawal process, according to the Daily Mail. With 40 to 60 percent of addicts relapsing after treatment or trying to maintain abstinence, the discovery that heroin users experience a reduction in levels of a certain protein in the brain that is responsible for forming synapses and maintaining their strength and function could mean approaching the treatment of heroin addiction in a whole new way.
The current standard in heroin treatment has been the use of medications such as buprenorphine and methadone, along with cognitive and group therapies. Although these medications have saved many lives, they have also contributed to cross-addiction to these milder opiates. To better understand the role of this protein—known as Drebrin—it's important to understand how synapses function, as well as how they are affected by addiction.
The brain is composed of neurons, or nerve cells, that when electrically stimulated, send, receive and process information using electrochemical signaling. Neurons are unique in nature, in that they never divide or die off for replacement by new nerve cells. There are around 100 billion neurons in the average human brain, all passing signals to one another through highly specialized connections known as synapses. When these vital neurological pathways aren't strong and healthy, brain function decreases. When damage is severe enough, the brain may stop working in vital ways and could result in paralysis, inability to speak, or brain death.
Synapses and Addiction
Addiction is one of the biggest threats to the health of synapses, with all addictive drugs affecting pathways that are involved in the reward circuit, in the form of a rush of intense pleasure. When addictive drugs stimulate the reward center in the brain, your synapses deliver a surge of dopamine as a reward. The effects are much more intense than with natural rewards, such as feeling loved, exercising, or eating good food. To compensate for this surge, the brain attempts to reduce the number of dopamine receptors at the synapse, which subsequently reduces the brain's response to natural rewards. As such, the early weeks of recovery from any addiction often involve intense cravings that may lead to relapse.
Study: Heroin Use, Drebrin, and Synapses
For the recent study published in Nature Communications, researchers exposed rodents to heroin and found that levels of Drebrin decreased with exposure. This occurred in the nucleus accumbens specifically, a region of the brain which plays a vital role in the brain's reward circuit. The drop in Drebrin affects how your brain communicates with itself significantly and drives the desire for more of the drug. Once Drebrin levels were restored to normal, relapse behaviors decreased. The motivation for the study was largely due to findings that reduced Drebrin levels have contributed to age-related diseases like Alzheimer's, and researchers were driven to compare the addicted and non-addicted brain in the hopes of similar findings.
Implications for Treatment
Although there has been limited research on the molecular mechanisms of heroin use and relapse, this discovery may be a turning point in the way heroin addiction is treated. The research team says the findings could eventually lead to medication-based therapies that target Drebrin levels to prevent relapse. "In the not too distant future, with all the findings, we can hopefully start to find real treatment to relieve the horrific conditions that people suffer from addiction and break the cycle of drug-taking, relapse, drug-taking, relapse," said senior author Dr. David Dietz, according to the Daily Mail.
Treating opiate addiction with milder opiates has helped many addicts reduce their use and eventually abstain, and has saved countless lives in the process. However, these opioid-based medications can prolong addiction to a milder form of their drug of abuse. These medications don't come without risks, but addressing the symptoms of heroin withdrawal from the standpoint of reversing brain chemistry may be a powerful new approach for preventing relapse without opioid-based medications.