While for most of us all knowledge of crystal meth comes from binge watching Breaking Bad, for about 12 million users in America this drug is part of their daily lives. A recent Canadian study has unearthed important data on regular meth addicts, after finding that young adults who've suffered a traumatic brain injury (TBI) are more than four times more likely to take the drug than those without a history of the injury.

The study, funded by the Canadian Institute of Health Research Team Grant in Traumatic Brain Injury and Violence and the Ontario Neurotrama Foundation, was published in The Journal of Head Trauma Rehabilitation.

The team of researchers interviewed 6,383 Ontario students between grades 9 and 12, and found that those who had sustained a traumatic brain injury were two to four times more likely to use the drug than their peers who never experienced TBI, according to the press release.

"Overall, a teen with a history of TBI is at least twice as likely as a classmate who hasn't suffered a brain injury to drink alcohol, use cannabis, or abuse other drugs," said Dr. Michael Cusimano, co-principal investigator of the study and a neurosurgeon at St. Michael's Hospital. "But when you look at specific drugs, those rates are often higher."

TBI is described as any hit or blow to the head that results in the individual being knocked unconscious for at least five minutes, or spending at least one night in the hospital due to symptoms associated with the injury. The researchers explained that some of these more milder cases of TBI may be referred to as concussions, but it’s important not to simplify this term.

"Some people think of concussions as a less alarming injury than a mild TBI, but this is wrong," Cusimano said. "Every concussion is a TBI. People should take every brain injury seriously because, as this research shows, the immediate and long-term effects can alter lives."

The researchers also warned that this dangerous link between drug use and head injury could have serious effects on young adult development. At the moment, however, the study was not able to determine which factor led to the other.

Crystal meth, short for crystal methamphetamine, is a colorless, odorless, highly addictive man-made stimulant. It is typically smoked in a glass pipe, similar to those used to smoke crack cocaine. Users may also inject the drug directly into their blood stream, as this increases the length of the high. According to PBS, meth users describe feeling a sudden rush of pleasure that may last for several minutes. This is then followed by a euphoric high that can last between six and 12 hours.

"All drugs of abuse cause the release of dopamine, even alcohol and nicotine," explained Dr. Richard Rawson, associate director of UCLA’s Integrated Substance Abuse Program to PBS. "[But] methamphetamine produces the mother of all dopamine releases."

Unfortunately, this ultimate high is also followed by an equally strong low, and users need to keep taking the drug to avoid depression.