Editor’s note: The following report is the second half of an article on the science of meth addiction. It is part of an ongoing series about the damage done by meth addiction.

According to most informational outlets available currently, the general consensus states that there are up to seven stages of a meth high, depending on a user’s length and severity of habit.

Each stage is sometimes referred to by different names depending on the source, but they are described in relatively the same way. For the purposes of this article, they are: The rush, the high, the binge, tweaking, the crash, the hangover and the withdrawal.

During the rush, a user experiences an increased heart rate and blood pressure, and can last for up to 30 minutes. This time frame is longer than drugs such as crack or cocaine, which typically lasts only minutes.

The rush is followed by the high. At this stage, it is common for a user to experience feelings of intellectual superiority. The high is also commonly signified by intense focus on something specific, and can last anywhere from four to 16 hours.

“The way it’s been explained to me, the initial high, the first time to ever use it, is so intense that you’re always chasing that first high,” said Turning Point Board Member Joe Siskar. “And meth is one of those strange drugs. It starts to change the chemical makeup of a person’s brain.”

The binge refers to the stage in which a user will continue using meth in order to maintain his or her initial high, and it can last for days or even weeks. This stage continues until the user is no longer able to experience a rush from new doses.

The tweaking stage occurs at the end of the binge. This is the stage in which a user can no longer navigate a functional sense of reality. It is often marked by intense hallucinations that can lead to a user becoming dangerous to him or herself or others. This is most often when a user becomes convinced that bugs are crawling under the skin, for example, and days of sleeplessness often accompany it.

“Meth actually starts to destroy the neurons in the brain that transmit the endorphins and the dopamine and all that,” Siskar said. “And that’s why there’s such a big personality change. The pseudo-reality becomes so strong with meth addicts that they forget what a normal reality is.”

Read the full version in this weekend's Graham Leader.