cocaine
© Global Look Press
Folks who snort lines of cocaine "only recreationally," to socialize and have fun with friends, are actually much closer to becoming hooked than they think, say researchers, who found that just watching someone using cocaine can bring on cravings.

Even among non-dependent cocaine users, cues associated with cocaine consumption trigger the release of dopamine, the so called "pleasure chemical," in an area of the brain believed to promote compulsive use, scientists at McGill University in Canada say.

This means that people that refer to themselves as modest, recreational users, who think they can give up at any time, could be much closer to being addicted than they think.

The study provides evidence that some of the characteristic brain signals in people who have developed addictions are also present much earlier than most of us would have imagined," Marco Leyton, an expert on neurobiology drug use and addiction and professor in McGill's Department of Psychiatry, said in a statement.

Just standing in the corner while quietly watching someone else using cocaine is enough to trigger a dopamine release and lead to cravings, the findings published in Scientific Reports say.

As the addiction gets worse, the cue-induced release of dopamine spreads towards the dorsal striatum, a structure deep inside the brain whose role in determining how we respond to pleasure brain has been intensively studied.

"This area of the brain is thought to be particularly important for when people start to lose control of their reward-seeking behaviors," Professor Leyton said.

"The dorsal part of the striatum is involved in habits - the difference, for example, between getting an ice cream because it will feel good versus being an automatic response that occurs even when it is not enjoyable or leads to consequences that you would rather avoid, such as weight gain or serious health hazards," he explained.

Scientists used positron emission tomography (PET) scans to see what happens in the dorsal striatum of recreational cocaine users. They filmed participants ingesting cocaine in the laboratory with a friend with whom they had used the drug before. The participants later underwent a PET scan while watching the video of their friend taking cocaine. Exposure to cocaine-related cues proved to increase both craving and dopamine release in the dorsal striatum.

"An accumulation of these brain triggers might bring people closer to the edge than they had realized," Professor Leyton said, highlighting the "importance of providing help early" to avoid the grave effects of dependency.