Re-thinking Addiction

At TAU's Dr. Miriam and Sheldon G. Adelson Center for the Biology of Addictive Diseases, scientists are researching new medications and therapies for the treatment of addiction
27 November 2012

The war on drugs makes headlines, but it’s the victims of addiction who are caught in the crossfire, facing a grueling road to recovery for which there are few effective treatments. And in cases of prescription drugs such as Oxycodone  or Ritalin, even patients in a clinical setting can fall prey to addiction. At TAU’s Dr. Miriam and Sheldon G. Adelson Center for the Biology of Addictive Diseases, scientists are analyzing – practically molecule by molecule  – the biological processes of addiction. They are advancing new and unexpected solutions and finding hidden properties to addictive drugs that may offer treatments for various degenerative diseases. Comprising researchers from a variety of disciplines, including neurobiology and psychology, the center is part of the Sackler Faculty of Medicine and is the first of its kind in Israel.

 

Taking the pain out of morphine withdrawal

The capacity of morphine to treat debilitating pain comes with a serious downside: it is a highly addictive drug. Withdrawal produces intense pain, diarrhea and other symptoms, all of which make recovery from addiction extremely traumatic for patients. Until now there has been no treatment that could completely and permanently alleviate the withdrawal symptoms from morphine addiction.

 

Prof. Yosef Sarne, a researcher at the Adelson Center who is investigating the properties of morphine, discovered that a miniscule dose of morphine – less than one thousandth of a normal dose – causes the same severe pain and diarrhea that occur during withdrawal from morphine. Prof. Sarne determined that the blood of patients undergoing withdrawal contains these same miniscule doses of morphine. Because the drug takes time to leave the body entirely, it may be these tiny quantities of the drug that cause the debilitating withdrawal symptoms.

 

Armed with this knowledge, Prof. Sarne is now exploring the possibility of treating morphine withdrawal by using naloxone, which prevents the binding of morphine to opiate receptors in the brain and thereby neutralizes the effects of the drug. In patients undergoing withdrawal, high doses of naloxone may prevent the painful side effects caused by small quantities of residual morphine in the bloodstream, and ease the road from withdrawal to recovery.

 

Developing a non-addictive pain killer

Researchers around the world are constantly in search of analgesic drugs that will treat pain as effectively as morphine, but without the addiction and side effects that make morphine so problematic. Currently it is known that a small dose of morphine combined with antidepressant drugs can amplify the efficacy of the morphine. Based on this principle, Prof. Chaim Pick is testing the effects of anti-depressant drugs in combination with methadone, a synthetic narcotic that behaves in a manner similar to morphine and heroin. Pick has discovered that the methadone-based formula may potentially work as well as morphine for the treatment of chronic pain—and possibly even better.

 

Treating neurodegenerative diseases and injury with marijuana

Marijuana has long been known to relieve pain and nausea, but the medical benefits may in fact be much more significant. Researchers at the Adelson Center are finding major medical properties in marijuana that could affect the way neurodegenerative diseases and brain injuries are treated.

 

Prof. Zvi Vogel

Isolating the components of marijuana and studying each individually can lead to significant medical advances, explains Prof. Zvi Vogel, the Director of the center. One of these components is cannabidiol (CBD), which Prof. Vogel has been investigating for the past three years, and which may allow a treatment for reducing the symptoms of degenerative diseases such as multiple sclerosis and Parkinson’s.

 

When microglial cells – the immune cells of the nervous system – are activated, their function is to attack pathogens that have entered their area. But when the microglia are activated for too long, chronic inflammation can result, which accompanies various neurodegenerative diseases. In the course of his research, Prof. Vogel has proven that CBD can reduce this inflammation, thereby potentially alleviating some of the crippling symptoms of these diseases.

 

Meanwhile, Prof. Sarne has produced research indicating that administering a very low dose of tetrahydrocannabinol (the major psychoactive component of marijuana) – about one-thousandth of the amount of a single cigarette – to the victim of a brain trauma within the first 24 hours can help minimize the injury. The technique enlists the brain’s own self-protective mechanism to keep damage from spreading.

 

Connection between Ritalin and cocaine

Ritalin is routinely prescribed for children with attention deficit hyperactivity disorder (ADHD). Yet the mechanism by which Ritalin works to calm children with ADHD, and its long-term effects on the brain, are still unknown to researchers. What is known is that the drug elicits dependence and has the potential for abuse by long-term users.

 

Prof. Moshe Rehavi, incumbent of the Adelson Chair in the Biology of Addictive Diseases, is researching the novel cellular and molecular modes of action of Ritalin and the relevance of neurobiological mechanisms that have been identified to the prevention of addictive behavior. Since Ritalin and cocaine are in the same drug class – they are both psycho-stimulant drugs – treatment for Ritalin addiction and withdrawal may extend to cocaine addiction and withdrawal, notes Rehavi. Like cocaine, Ritalin increases the release of the neurotransmitter dopamine and inhibits its reuptake in the brain, thereby stimulating motivation and energy. “Students in every university are taking Ritalin, without being diagnosed with ADHD, just to be more focused and have more energy,” Rehavi explains. “This is a bad thing, because in the longterm, high doses of Ritalin may lead to addiction.”

 

Yet in children with ADHD, Ritalin has the opposite effect: instead of increasing their energy level, Ritalin calms them down. Rehavi describes this paradox as an “enigma” for which there is currently no known explanation. In studying the long-term effects of Ritalin on the brain, Rehavi aims to uncover the mystery and help patients cope with the challenges of withdrawal from the drug. “Rather than just treating the severe side effects of withdrawal as is currently done today, our goal is to treat the entire process.”

 

The Dr. Miriam and Sheldon G. Adelson Center for the Biology of Addictive Diseases was founded by addiction researcher and clinician Dr. Miriam Adelson and her husband, Sheldon G. Adelson, both TAU honorary doctors. Dr. Adelson earned her MD at TAU’s Sackler School of Medicine.

 

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