The active ingredient in the attention deficit-hyperactivity disorder (ADHD) medication Ritalin may help cocaine-dependent adults better manage their impulse control. According to a new study released on Monday in the Proceedings of the National Academy of Sciences journal, the medication methylphenidate, which helps decrease hyperactivity and impulsive behavior in ADHD patients, may also help those suffering from substance abuse addictions by boosting the brain’s impulse-control mechanism.

Yale University professor Chiang-shan Ray Li and colleagues conducted a pharmacological study in which volunteers with cocaine addiction were tested on their impulse control after being administered either the psychostimulant methylphenidate or a placebo. Like people with ADHD, individuals with drug addictions have difficulty controlling their impulses as their dependency grows. These individuals gradually succumb to habitual drug-seeking behavior and drug consumption despite severe consequences. As a result of this addictive behavior, the brain’s inhibitory control becomes impaired.

Psychostimulants like Ritalin have proven to be effective in helping ADHD patients cope with impulse control issues and better manage their symptoms, as it is believe to activate the brain’s stem arousal system and cortex by producing a stimulant effect. In this study, researchers sought to discover if the same medication was also effective in treating those with impulse disorders such as cocaine addiction.

Participants were assessed based on their responses to a computer test in which they were asked to quickly press a button when given a “go” cue, but to resist pressing the button when given a “stop” cue. These cues randomly appeared on a computer screen, sometimes with the “stop” cue immediately following a “go” cue. During the assessment, participants were monitored with magnetic resonance imaging (MRI) scans of their brain activity to show researchers their brains’ ability to initiate a ‘stop signal.’

As a result of the assessment, participants who were given methylphenidate were significantly more capable of igniting the brain’s stop signal reaction than those who were administered a placebo. Not only did these participants better resist pushing the test button, but their MRI scans also showed higher activation in the brain region where inhibitory control takes place. This brain region, known as the ventromedial prefrontal cortex, is crucial to managing behavioral control especially during emotional or stressful situations. When the same participants were tested again two days later but were given a placebo instead of methylphenidate, the results reflected a dramatic decrease in their ability to control their impulses. Methylphenidate thereby increased central nervous system activity and prefrontal activation in individuals with cocaine addictions—helping them to suppress their impulses.

The Yale University study, however small and preliminary to methylphenidate’s use in addiction therapy, did show that the ADHD medication has much potential in combating cocaine addiction. Given the evidence from their study, the researchers advise that methylphenidate may offer more options to addiction medicine once further research into its ability to control addictive behavior is established. Incorporated with individualized treatment, methylphenidate could help cocaine-dependent patients overcome their addictions in the future.

Sources: The Los Angeles Times, Shari Roan, Can Ritalin Help People Overcome Drug Addiction?, July 26, 2010

AFP, Attention Deficit Medication Helps Drug Addicts: Study, July 27, 2010