Exactly how the brain is tricked into addiction through substance abuse has been found by researchers at Brigham Young University and at the University of Toronto in Canada.

The breakthrough findings to be published online Friday in the prestigious journal Science show that the protein in the brain that controls the release of pleasure biochemicals induced by opiates in painkillers such as alcohol, heroin and prescription drugs like OxyContin switches the brain into an addictive state.

By injecting doses of the naturally occurring protein that controls the release of the dopamine neurotransmitter in the brain, laboratory rats became "hooked," even without drugs, the researchers found.

In describing the process to the newspaper, BYU neuroscientist Scott Steffensen said that while earlier research showing the protein that controls the tap to the pleasure chemicals was involved in the release of dopamine, this study showed for the first time how a brain-derived neurotrophic factor can be switched on without drugs.

"This study shows pretty clearly that if we can understand how the brain's circuitry changes in association with drug abuse, we can find ways to medically counteract the effects of dependency," Steffensen said.

The pleasure response in the brain's reward circuitry is induced by normal activity ranging from breathing in fresh spring morning air to doing well on a test to eating a good meal to falling in love to sexual release and the euphoria that occurs with the birth of a child.

When the response is constantly put into overdrive with depressants such as alcohol and painkillers or stimulants such as methamphetamine, the protein tap is turned wide open and the pleasure response spikes.

"The value of the research is it reveals the mechanism behind drug addiction," said lead author Hector Vargas-Perez, a neurobiologist at the University of Toronto whom Steffensen credits with doing "the hard work" in the study.

Pat Fleming, executive director of the Salt Lake County Division of Substance Abuse, said Thursday that the finding couldn't be more welcome or come at a better time.

"We are more overwhelmed by requests for help than I've ever seen," he said, noting that demand is part and parcel of a tanking economy and the paring off of substance abuse treatment from insurance plans. "Any research that provides a hope for insight or a new tool to help people is huge."