September 2016 A brain imaging study strongly suggests that regular users of marijuana have smaller orbitofrontal cortex (OFC) volumes. Such a deficit could make it more difficult to change counterproductive behaviors, including drug use.
March 2008 Describes a new chemical tracer that binds specifically to cannabinoid receptors making it potentially useful in future research to clarify the relationship between the receptors and drug abuse.
November 2011 Individuals with weak signaling in a nicotine-sensitive brain circuit were more vulnerable to nicotine dependence than those with stronger signaling, according to a study conducted while the subjects’ brains were in a resting state. A second resting-state study finds that the same circuit appears to mediate dependence associated with a genetic risk factor for smoking.
June 2015 A stressed rat will seek a dose of cocaine that is too weak to motivate an unstressed rat. Researchers traced the physiological pathway that links stress and the stress hormone corticosterone to increased dopamine activity and heightened responsiveness to cocaine.
November 2012 NIDA-supported research suggests that glucocorticoid receptor levels during early brain development affect the hard wiring of neural circuits that shape an individual’s basic emotional makeup. In mice, overexpression of the glucocorticoid gene in the first weeks after birth increased anxiety and response to cocaine in adulthood. These findings may help researchers understand the genetic background and the developmental trajectory of addiction.
January 2014 Ketoprofen, an anti-inflammatory agent commonly prescribed to treat arthritis, reduces neuronal damage in rats that have been exposed to chronic stress and methamphetamine. If this finding of a recent NIDA-supported study extrapolates to humans, anti-inflammatory medications may gain a place in the treatment of methamphetamine addiction.
November 2014 Methamphetamine use and HIV infection raise the risk for functional dependence, or the need for assistance with everyday tasks. People who use methamphetamine and are HIV positive showed the highest levels of functional dependence in most domains of daily life.
November 2013 A meta-analysis of 13 genome-wide association studies of African Americans’ smoking patterns confirms the significance of genetic variation in region 15q25.1. The analysis also tentatively implicates several genome locations that have not previously been associated with smoking behaviors.
August 2013 New research demonstrated that, in rhesus monkeys, ongoing cocaine exposure weakens two brain functions that people require for successful behavioral change: cognitive flexibility and memory. But the study determined that these changes may not be permanent.