The Scientific Director of NIDA’s Intramural Research Program talks about switching off animals’ compulsive cocaine seeking by optogenetically activating the prefrontal cortex, and the implications of this work for people. In an accompanying podcast, Dr. Bonci walks viewers through experiments that showed that prefrontal cortex activity levels may constitute a simple switch controlling whether or not animals compulsively seek cocaine.
Two recent studies suggest that genotyping may enable clinicians to base therapies on individual patients’ potential responsiveness to opioid drugs’ therapeutic effects and vulnerability to their harmful effects.
A brain response occurs in the nucleus accumbens when rats encounter a cue that they associate with previous cocaine self-administration, but not a cue associated with a pleasurable non-drug experience. Moreover, the response correlates in time and intensity with the animals’ cue-induced relapse to cocaine-seeking.
Driving under the influence of marijuana is a dangerous public health concern. NIDA researchers have discovered that breath expelled into a Breathalyzer-style collection device contained measurable amounts of THC for up to 2 hours after participants in a recent clinical trial smoked the drug.
One of NIDA’s goals is to try to understand the individual differences that contribute to whether or not someone who takes a drug will become addicted to it. Dr. Rutter’s research focuses on three types of differences: Environmental, developmental, and genetic and epigenetic.
Exposing rats to THC increases the likelihood that the animals will later self-administer nicotine. THC-exposed rats are also willing to work harder to obtain nicotine. When extrapolated to people, the findings suggest that THC’s pharmacological impact on the brain may make a person who uses marijuana more vulnerable to developing nicotine addiction, an underappreciated health consequence of marijuana use.
Almost one-third (32 percent) of the roughly 42,000 Monitoring the Future survey respondents reported having used marijuana during their lifetime. However, abuse of many other drugs—methamphetamine, heroin, cocaine, and some prescription medications—declined.
Intensified screening for HIV among injection drug users receiving opioid agonist therapy could prevent more than twice as many new infections as current screening practice. A recent study based on mathematical modeling found that screening every 6 months instead of annually, and adding viral RNA testing to the currently used HIV antibody testing, could improve both effectiveness and cost-effectiveness.
Active drug use before incarceration was associated with decreased engagement in HIV treatment among HIV-infected jail detainees. The severity of drug dependence correlated with worsening measures of engagement in HIV treatment. The study concludes that evidence-based treatment for drug abuse in jails may result in improved HIV treatment outcomes, which in turn could help slow HIV-transmission rates in the United States.