A New Way of Looking at Addiction Treatment
For example, a once-a-month alcoholism shot (called naltrexone) could help keep high-risk heroin addicts from relapsing; a drug to help narcolepsy could help treat cocaine addiction; and an old antidepressant might help meth addicts.
Dr. Volkow explained that today’s goal is to change the underlying brain circuitry that leads some substance abusers to relapse, not just temporarily blocking an addict’s high.
It's "a different way of looking at mental illnesses, including substance abuse disorders," she said.
Scientists believe that instead of being a problem in a single brain region, psychiatric diseases like addiction and depression are spread over multiple brain regions, making it harder for the regions to communicate and work together. This dysfunction plays an important role in addiction.
This overlapping helps explain why addictions often go hand-in-hand with other disorders, such as depression, anxiety, schizophrenia, post-traumatic stress disorder, and other conditions. This is called co-occurring disorders, or dual diagnosis.
Dr. Volkow explained that the orchestration of brain circuits is disrupted in psychiatric illnesses. "There's not a psychiatric disease that owns one particular circuit,” she said.
As a result, NIDA is calling for more research into treatments that could target the brain circuits involved with cognitive control, better decision-making, and resistance to impulses.
So far, the manufacturer of naltrexone, Alkermes Inc., asked the Food and Drug Administration to help approve the drug as a treatment for heroin and other opioid addiction. Naltrexone is already sold as a monthly shot to help treat alcoholism. It has already been shown that naltrexone pills can help block the effects of heroin, but the pills only last one day, so skipping a dose makes it possible for addicts to get high again. The monthly version, called Vivitrol, can help block the effects of heroin in the long-term. Dr. Volkow also explained that a study in Russia found that naltrexone shots also reduced cravings for heroin and opioids, which could help prevent relapse.
Modafinil, currently used to help narcoleptic people stay awake, has also been found to help cocaine addicts as it reduces their cravings for the drug. Some research suggests that modafinil also improves decision-making, which could help prevent relapse.
Bupropoin, an old antidepressant currently used for smoking cessation, is being tested for methamphetamine addiction based on early research suggesting that it reduces the high. Because addiction makes the brain more sensitive to stressors that in turn trigger negative mood circuitry, Dr. Volkow said she wants antidepressants also to be tested in combination with other addiction medications.
Aside from medication, biofeedback has been used to teach people with high blood pressure how to control their hear rate, so researchers are looking into whether biofeedback can teach addicts how to control their drug cravings.
Source: The Associated Press, Lauran Neergaard, Targeting Brain Circuits for Addiction, Relapse, May 24, 2010.