ADHD drug may treat cocaine addiction

A single dose of a commonly-prescribed attention deficit hyperactivity disorder (ADHD) drug helps improve brain function in cocaine addiction, scientists have found.
Researchers from the Icahn School of Medicine at Mount Sinai in New York found Methylphenidate (brand name Ritalin) modified connectivity in certain brain circuits that underlie self-control and craving among cocaine-addicted individuals.
Previous research has shown that oral methylphenidate improved brain function in cocaine users performing specific cognitive tasks such as ignoring emotionally distracting words and resolving a cognitive conflict.
Similar to cocaine, methylphenidate increases dopamine (and norepinephrine) activity in the brain, but, administered orally, takes longer to reach peak effect, consistent with a lower potential for abuse.

By extending dopamine's action, the drug enhances signalling to improve several cognitive functions, including information processing and attention.
"Orally administered methylphenidate increases dopamine in the brain, similar to cocaine, but without the strong addictive properties," said Rita Goldstein, Professor of Psychiatry at Mount Sinai, who led the research while at Brookhaven National Laboratory (BNL) in New York.

"We wanted to determine whether such substitutive properties, which are helpful in other replacement therapies such as using nicotine gum instead of smoking cigarettes or methadone instead of heroin, would play a role in enhancing brain connectivity between regions of potential importance for intervention in cocaine addiction," Goldstein said.

"Using fMRI, we found that methylphenidate did indeed have a beneficial impact on the connectivity between several brain centers associated with addiction," said Anna Konova, a doctoral candidate at Stony Brook University and first author of the study.
Goldstein and her team recruited 18 cocaine addicted individuals, who were randomised to receive an oral dose of methylphenidate or placebo.
The researchers used functional magnetic resonance imaging (fMRI) to measure the strength of connectivity in particular brain circuits known to play a role in addiction before and during peak drug effects.
They also assessed each subject's severity of addiction to see if this had any bearing on the results.

Methylphenidate decreased connectivity between areas of the brain that have been strongly implicated in the formation of habits, including compulsive drug seeking and craving.
"The benefits of methylphenidate were present after only one dose, indicating that this drug has significant potential as a treatment add-on for addiction to cocaine and possibly other stimulants," said Goldstein.
The study was published in the journal JAMA Psychiatry, a JAMA network publication.