A study by the Centre for Health and Prevention Studies at New York University has found that the use of tik leads to dangerous sexual behaviour.
The street drug crystal methamhpetamine, known as tik in South Africa, increases the chance of men who have sex with men to contract HIV by 400%, according to a US study.
But according to Hetta Gouse, a neuropsychologist in the psychiatry and mental health department at the University of Cape Town (UCT), the impact of tik addiction on HIV infections in South Africa is likely to extend far beyond this group.
"While men who have sex with men are the main consumers of the substance in America, in South Africa it is also used in high numbers by heterosexual men and women. The figures are the highest in the Western Cape and KwaZulu-Natal."
Gouse is conducting a study on the rate of HIV infections among tik users in the Western Cape. "Research has shown that tik users take significantly higher sexual risks, which heightens the spread of HIV," she said.
Over the past decade there has been a drastic increase in tik abuse in the Western Cape: whereas only 0.3% of Cape Town patients admitted to rehabilitation centres reported tik as a substance of abuse in 2002, it increased to 49% in 2007, according to a Medical Research Council study.
Pleasure and pain
Tik - also referred to as speed, meth or globes - is a stimulant that affects the central nervous system. In South Africa it is typically sold as a white powder or slightly larger crystals packaged in a straw that sells for R20 to R30. American users tend to inject the drug, but South Africans mostly smoke it with the use of a heated light bulb.
The drug releases a chemical called dopamine in the brain that influences emotions and sensations of pleasure and pain. According to The Body, a US-based HIV website, tik and cocaine work in similar ways. But the effects of tik are significantly stronger and last much longer: whereas cocaine increases dopamine concentrations to about 400% of normal levels, tik boosts them by up to 1500%, giving users "intensely pleasurable" highs that can last for 12 hours.
"Tik not only increases libido, but it also allows you to have sex for much longer periods at a time," said Kevin Rebe of the Ivan Toms Centre for Men's Health in Cape Town. "And the longer you go the more friction and abrasion there is, thus the higher the risk of damage to barrier surfaces through which HIV can enter your bloodstream."
Studies have indicated that tik users have more sexual partners and fewer inhibitions than those who do not use it. A San Francisco University study found that tik consumers "could have sex without guilt or the mental distractions of shame or embarrassment", The Body reported. "Those using the internet to find partners said that the loss of inhibition allowed them to have sex with 'whoever showed up' at the door at 3am in the morning."
Users also were more willing to explore new behaviours and "ero-genous zones", leading to them taking on new sexual roles. Gay men who would generally be the "insertive partner" during anal sex might therefore became a receptive partner during a tik-taking session.
"The riskiest sexual behaviour for HIV transmission is unprotected, receptive anal sex. It doesn't matter whether you're a man or a woman," said Rebe. "Other than releasing HIV straight into a vein, that's the surest way of getting HIV because anal sex causes many abrasions that allow the virus to enter the body."
Tik also leads to impotency in some men, which could cause them to become receptive partners during male sexual encounters.
According to New York University, tik "highs" are followed by "crashes" during which the brain's dopamine levels plummet far below the usual amounts present, resulting in intense depression and excessive fatigue. "The fact that the body has been blind to hunger, exhaustion and nutrition also contributes to the crash since a user's system depletes stored energy supplies in the body, leaving little left for the recovery period," the university's Centre for Health and Prevention Studies said. A user becomes more susceptible to disease, including HIV infection, during this period because the body is completely run-down.
Tik has also been shown to speed up HIV replication in both test tube and animal studies. A 2009 published study in the academic journal Aids Research and Human Retroviruses found that HIV-infected mice consuming tik progressed to the level of Aids more quickly than those that were not given the stimulant.
According to Gouse, HIV-positive consumers of the substance experience more negative effects on the brain than non-users. "About half of people with HIV may experience some sort of neurocognitive disorder, including memory and attention difficulties. HIV and tik, however, affect similar areas of the brain. Tik users may therefore experience more severe cognitive damage," she said.
Tik use and rape figures
Taking HIV medication while on tik also heightens the risk of overdosing because of drug interaction. "HIV therapy, if started before the use of [tik], can elevate the level of drugs or alcohol in your blood as the liver processes the HIV meds while leaving the other drugs circulating in the blood. This can lead to an overdose," New York University reported.
Although no studies have formally linked the two, there is likely to be a correlation between tik use and South Africa's high rape figures, according to research.
"Tik has been linked to violent behaviour. It is logical to think that sexual acts will also be more aggressive. As the drug lowers inhibitions, women who use tik and are coerced into sexual acts will probably also be less resistant," said John Joska, a senior specialist in UCT's psychiatry and mental health department.
He is leading a study to examine how tik makes people more impulsive and open to risky sex and more vulnerable to HIV infection.