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A team at The Scripps Research Institute has found significant evidence regarding the neurobiology of addiction that a specific neurotransmitter system, the endocannabinoid system that includes the most common CB1 receptors, is active in the brain region that plays an important role in appetite, memory, mood/ emotion, and addiction. The study, which was recently published in Neuropsychopharmacology, also found that endocannabinoid system can inhibit the effects of alcohol, thus offering promise for future prevention and rehabilitation strategies.

According to a professor of the neurobiology of addiction at Scripps Research, this is the first study to show a “direct cellular interaction between endocannabinoids and alcohol in the brain.” (Science Daily)

The study abates a paper published in 2001 in the Journal of Neuroscience, in which a European group asserted that endocannabinoid receptors (CB1 receptors) did not exist in the brain region known as the central amygdala (which is part of the limbic / reward system of the brain). This paper’s conclusions were widely accepted by the the field. However, the scientists at The Scripps Research began to suspect that the presence of CB1 receptors in the central amygdala had somehow been missed. Especially since, as many of the scientists at Scripps, said that they began studying the endocannabinoid system in the central amygdala because of addiction. And they found that CB1 receptors are very abundant throughout the brain.

One of the scientists reiterated that there has been numerous behavioral studies on substance abuse, but a very limited amount on the physiology of addiction. And aside from the 2001 study, even less on the physiology in the central amygdala (a region of the brain that is key in understanding the drug and alcohol abuse).

Using electrophysiological techniques in brain slices to test the response of brain cells from the central amygdala in rats, the scientists found compelling evidence that CB1 receptors were active there. They also determined that alcohol and CB1 agonists have opposing effects on GABA (which is a main inhibitory neurotransmitter in the brain that fine-tunes signaling throughout the nervous system. GABA plays a key role in alcohol dependence and other addictions.) The scientists concluded that because there is such a wide presence of CB1 receptors, there is a greater possibility of inhibiting the effects of alcohol.

In an effort to build positive awareness about women’s health, it’s important to address the gender-specific issues surrounding drug and alcohol addiction and recovery. May 9-15, 2010 is the 11th Annual National Women’s Health Week, initiated by the U.S. Department of Health and Human Services’ Office. The week-long, nationwide celebration/ health observance encourages communities and organizations to combine efforts in educating and rally women to take steps towards improving their physical and mental health. The theme of the week is “It’s Your Time,” which is a reminder to women that although “they are often the caregivers for children, spouses, and parents, they need to make sure they take the time to focus on their own health.” (SAMHSA)

While the rate of retention for women in substance abuse treatment programs is similar to men, it’s necessary to discuss the gender-specific variables that may significantly influence the long-term success of rehabilitation and recovery.

In this respect, women’s treatment issues and needs often vary a great deal from men’s (let alone on an individual basis). With this in mind, such issues in need of addressing may include: the role of relationships (including family and partners); parenting issues and treatment needs (including pregnancy and children); and possible co-occurring disorders (anxiety, mood, or eating disorders) that are prevalent among women and may need attention during substance abuse treatment. Trauma and trauma-related symptoms may also need significant consideration when designing the treatment protocol. Here is a link to the SAMHSA/ CSAT Treatment Improvement Protocols: Chapter 7: Substance Abuse Treatment for Women.

As we’ve discussed before, alcohol affects women differently than men because of the difference in body make-up and chemistry. Such factors as women’s bodies having more fat and less water than men’s and women processing less alcohol in the stomach than men, contribute not only to women becoming more intoxicated faster than men, but to higher risk factors for women’s overall health. “Effects of Alcohol on Women” (Women and Alcohol – SMAHSA) is a great, quick breakdown of the situation.

A recent study by the University of Texas reports one of the most exciting neuroscience discoveries to date regarding prevention, as reported by the Scientific American, that addresses why some people are more prone to drug and alcohol addiction than others. What they found: there are new neurons born in the adult brain. This study, which was published in the Journal of Neuroscience, could hold key insight to prevention mechanisms and future models of studying addiction.

To show that a lack of neurogenesis, or birth of new neurons, can actually cause drug or alcohol addiction, the researchers blocked neurogenesis, the production of new neurons, in the hippocampus region of the brain of rats. They found the rats with fewer newborn neurons were more likely to become addicted and more likely to relapse after withdrawal or detox periods. The researches speculated that this may be the reason some people are more at risk when it comes to substance abuse. Based on the study’s results and evidence from other studies on addiction and the hippocampus, the research suggests that newborn neurons may inhibit the release of dopamine (a major chemical messenger of rewards signals in the brain). Also, people with fewer newborn neurons may get a bigger dopamine rush with the use of drugs or alcohol than others.

This is the strongest evidence to date in support of there being real biological reasons as to why some people might be more vulnerable to addiction than others. And it gives a better idea of the role of newborn neurons in the brain. Neuroscience research on addiction has mainly focused on the role of the reward centers in the brain, more increasingly, the hippocampus. In light of now knowing that new neurons are born in the hippocampus, recent research has sought to understand how adult neurogenesis is involved in addiction. The researchers concluded that there is a direct correlation between neurogenesis and addiction.

Ultimately this theory could lead to testing individuals for the presence of newborn neurons and may predict their predisposition or increased risk of addiction. This could prove to be an invaluable prevention and rehabilitation tool.