Ice has been called the most dangerous and destructive drug of our time. But what exactly does it do to your body?

Ice, along with speed and base, is a form of the potent stimulant drug methamphetamine.

Also referred to as shabu, crystal, crystal meth or d-meth, ice is the purest and most potent form of methamphetamine. It comes as a powder or crystals that are usually snorted, injected or smoked.

The latest figures from the National Drug Survey suggest 2 per cent of Australians use methamphetamine – a figure that hasn’t really changed much over the last decade, says Nicole Lee an Associate Professor at the National Centre for Education and Training on Addiction at Flinders University.

But about half of those who use methamphetamines say they prefer to take ice, and the number of people using ice has doubled since the last survey, says Lee.

The initial high

How quickly you feel the effect of methamphetamine depends on the form, the route of administration and how much of it you use, explains Lee.

“Mostly people will smoke, inject or swallow a pill,” she says. Sometimes people dissolve it into alcohol or water and drink it.

“If you smoke it, it has an immediate high, just in a couple of minutes you’ll get quite a big hit. Whereas if you ingest it through your stomach it’s about 20 minutes before you start to feel the effects.”

The immediate effects from ice are intense pleasure and clarity. Users say they have lots of energy and can think clearly, feel like they can make good decisions, and plan effectively.

This is because methamphetamine dramatically increases the levels of the hormone dopamine – by up to 1,000 times the normal level – much more than any other pleasure seeking activity or drug.

Physical effects can include dilated pupils, an increased heart and breathing rate, a reduced appetite and an increased sex drive.

The effects usually last for between four and 12 hours, although methamphetamine can be detected in blood and urine for up to 72 hours.

Coming down

It might sound obvious, but if you’re coming down from methamphetamine you’re likely to feel the opposite of what you feel when you’re the high. So you’ll have trouble making decisions, poor concentration and difficulty planning.

You may also have headaches, blurred vision and start to feel hungry.

It’s pretty common to feel flat, depressed, jittery and anxious. As well you may feel exhausted and want to sleep for a day or two, although you may have difficulty sleeping, explains Lee.

Some people may also feel very irritable or have mild psychotic symptoms like paranoia and hallucinations.

“The ‘come down’ period is like a hangover, a recovery period after which people may move into withdrawal if they are dependent,” she says.

Double-whammy harm

Once users start to take ice at higher doses or to use it more frequently, the pleasurable effects tend to give way to less pleasurable ones, says Lee.

Physically this might involve a racing heart and increased breathing rate, a rise in body temperature, a dry mouth and sometimes nausea and vomiting.

At ‘critical toxicity’ or overdose levels, people can also have stroke or heart failure, and occasionally seizures.

Once you start taking higher doses you may also start to feel jumpy or anxious, hostile and aggressive. This can escalate to feelings of intense paranoia or psychotic episodes.

This is caused by methamphetamine’s release of another neurotransmitter (brain chemical) called noradrenaline, which induces a ‘fight or flight’ response.

It’s these users that typically turn up in emergency departments and pose a challenge to medical staff, says David Caldicott an Emergency Consultant at the Calvary Hospital in Canberra.

This is because they are often dealing with methamphetamine’s “double-whammy” of physical as well as psychological effects, he says.

For instance a user could present to emergency with stroke like symptoms but be severely agitated and aggressive.

“It’s kind of a Benjamin Button type drug so… [you could] see a stroke or aortic dissection in someone using ice in their 20s or 30s,” he says.

Regular lows

It takes between 10 to 14 days to physically detox from methamphetamine, almost twice as long as many other drugs. After an acute withdrawal period, there’s a more chronic withdrawal period that may take 12 to 18 months.

“It makes it very difficult for people to get off because having cravings, feeling really flat, jumpy and anxious for over a year and a half is a long time,” says Lee.

One of the reasons it’s so difficult to come off ice and other methamphetamines is that the drugs target the dopamine system. Regular and huge bursts of dopamine can effectively wear the relevant brain regions out, so the brain is no longer able to produce enough dopamine.

“The feeling that you get when you have lots of dopamine in your system is a feeling of incredible pleasure so when the dopamine system wears out, people really feel very flat, and depressed,” says Lee.

In order to feel ‘normal’, users need more methamphetamine on board, which is one of the reasons relapse rates are so high.

But Lee says research shows that changes to the dopamine system are recoverable over time.

Overstating the dangers of  may impede treatment of drug abusers, asserts a review by Columbia University researchers.

The 1936 film Reefer Madness developed a cult following because of its over-the-top depiction of the evils of marijuana. Getting stoned and going to a midnight showing became a ritual for many college students.

The recognition that pot is not a direct route to an asylum for the criminally insane, as it was for one character in the film, fueled the hilarity for late-night moviegoers. The divergence between perception and reality has become an issue in recent years for other recreational drugs.

Last month four scientists from Columbia University published an analysis of previous studies on methamphetamine use that called into question some of the purported damaging effects of the drug on brain functioning. The review in Neuropsychopharmacology found that short-term effects of the drug actually improve attention, as well as visual and spatial perception, among other things.

Moreover, chronic users—the ones who would be expected to suffer most—remain largely unimpaired. The researchers found that they experience brain and cognitive changes “on a minority of measures” in brain imaging and psychological tests. “Cognitive functioning overwhelmingly falls within the normal range,” the report states, while adding that researchers’ pre-existing assumptions about meth’s detrimental effects “should be reevaluated to document the actual pattern of cognitive effects caused by the drug.”

While recognizing the potential for abuse, the researchers emphasize that misinterpretations of the scientific evidence can wrongly stigmatize drug abusers and lead to misguided policymaking. One study, for instance, asserted that meth abusers might be too cognitively damaged to benefit from rehabilitative treatments, such as cognitive behavioral therapies. “Findings from this review argue that such concerns are unwarranted,” the researchers state.

In Thailand, efforts to stem meth use have gone as far as banning all amphetamines, a class of drug that is used medically for treatment of ADHD and other conditions. “My main goal really was to make sure that we are rigorous in the science before we are political,” says Carl Hart, a substance abuse researcher at Columbia who was the lead author on the Neuropsychopharmacology paper. “I think, with meth, we have been political.” (Neuropsychopharmacology is part of Nature Publishing Group, which also includes Scientific American.)

The article asserts that some of the misconceptions surrounding meth go beyond findings on mental functioning. Drug education campaigns often publish photographs of “meth mouth,” severe tooth decay among users because of the lack of saliva. But dry mouth is a condition common to other drugs, such as the prescription antidepressant Cymbalta and the ADHD medication Adderall.

Hart says he was impelled to do the research because of distortions of the evidence for harm from crack cocaine. During the crack cocaine epidemic in the 1980s and 1990s, pronouncements about lasting prenatal harm to children whose mothers used the drug turned out to be overblown: long-term effects on brain development and behavior were fairly small, and children were sometimes ostracized or received medical diagnoses that were mistakenly attributed to effects from the drug.

The review by Hart and colleagues elicited a firm counterpoint from National Institute on Drug Abuse director Nora Volkow, some of whose research is critiqued in the Neuropsychopharmacology paper. “Because of the far-reaching public health implications of this issue, it is essential not to forget what we do know about meth-induced neuropathology, which is plenty troubling,” she says. Volkow points out that the vascular effects of meth can lead to strokes and hemorrhages. The drug, she notes, has also been shown to produce inflammation, atrophy and structural changes in brain tissue. “Similarly worrisome is a recent report of increased incidence of Parkinson’s diseases among individuals with a past history of methamphetamine abuse [compared with] the general population,” she says, adding that meth abuse can be “neurotoxic to the human brain.”

Hart responds that he and his colleagues were careful to consider the full body of scientific literature, including animal studies. He points out that many animal studies used to extrapolate possible deleterious cognitive effects in humans had administered large amounts of methamphetamine from the outset, a regimen unlike the gradual escalation in dosing undertaken by illicit drug users, which avoids these consequences. The article emphasizes that serious medical consequences, such as paranoia and hypertension leading to stroke, are rare and only result from sustained ingestion of very large doses.

Meth’s persistent bad boy reputation means that medical marijuana dispensaries will not be expanding their offerings to include speed any time soon. Still, the idea is not as totally outlandish as it might seem.

A much cited commentary that appeared in Nature in December 2008—an article co-authored by neuroscientists and ethicists—raised the prospect of routine use of “cognitive enhancement” drugs by the general public if they could be proved safe.

The few drugs already on the market that come closest to meeting the definition of cognitive enhancers include Adderall (dextroamphetamine and amphetamine) and Ritalin (methylphenidate), close chemical cousins of methamphetamine. Ritalin and Adderall, in fact, have developed a reputation as executive’s little helpers in the business world and were cited in the Nature commentary.

Hart and his colleagues never suggested that methamphetamine could serve as a pick-me-up for meeting pending work deadlines. Their review, though, looked at more than 10 studies that found that short-term use of meth actually improves several cognitive measures, precisely the kind of evidence the authors of the Nature article were calling for when considering the merits of enhancement.

The debate over methamphetamine, used widely by soldiers during World War II, reveals the ambivalent societal relationship toward potentially addictive compounds that can also serve as performance boosters. The hate-love relationship will likely continue into the indefinite future.

Source:Scientific American.