National Amphetamine-Type Stimulant Strategy Background Paper: Monograph Series No. 69
3.5 Negative behavioural and social effects
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Several adverse effects can arise from behaviours associated with ATS use. Sexual risk taking, driving while impaired and polydrug use have been associated with both meth/amphetamine and ecstasy use, while aggressive and violent behaviours are more often associated with methamphetamine use. Riley and colleagues (2001) identified the main risks for young people who use ecstasy as polydrug use (85%), driving while intoxicated (35%) and unprotected sex (30%).
Polydrug use
Meth/amphetamine and ecstasy users are frequently described as ‘polydrug users’, referring to frequent use of other drugs. Sometimes other drugs are used separately to ATS, sometimes simultaneously (e.g., alcohol) and sometimes to manage some of the adverse effects of ATS use (e.g., drugs used to manage the ‘crash’). The 2004 NDSHS found that across all reported drugs, recent ATS users had substantially higher rates of polydrug use than non-ATS users, including three times the rate of smoking and almost ten times the use of cannabis (Australian Institute of Health and Welfare, 2005a). It was reported that 87% had consumed alcohol, 68% had used cannabis and 49% had used MDMA with methamphetamine on at least one occasion. Thirty eight percent reported alcohol use as a substitute when methamphetamine was not available, while 24% nominated MDMA as the next most common substitute. With regards to MDMA users, the 2004 survey noted that 83% had consumed alcohol with MDMA on at least one occasion, 57% had used cannabis with MDMA and 39% had used methamphetamine with MDMA. Alcohol was nominated by 42% as the preferred substitute when MDMA was not available, followed by 24% nominating methamphetamine as their next most common substitute.The most recent EDRS survey found that among REU, 99% reported lifetime use of alcohol and 96% reported use of alcohol in the previous six months (Dunn et al., 2007). Similarly, 98% reported lifetime cannabis use and 83% reported cannabis use in the previous six months. More than three-fifths of the sample reported lifetime ‘speed’, crystal methamphetamine, cocaine and LSD use; more than one-third reported recent use of crystal methamphetamine, base and cocaine. Of the total sample, 93% reported usually using other drugs with ecstasy and 80% to ‘come down’ from ecstasy. Alcohol was the most common drug reportedly used with ecstasy (75%), followed by tobacco (64%) and cannabis (45%). Cannabis was the most commonly reported drug used during ‘come down’ (70%), followed by tobacco (64%) and alcohol (41%). Rates of methamphetamine use with ecstasy were low, with speed the most common (27%), and less than 10% reported using a form of methamphetamine during ‘come down’.
Focus group discussions among ecstasy users have also found that combining ecstasy use with alcohol was the most commonly reported risk behaviour (Shewan et al., 2000). In addition, other drugs, most notably cannabis, LSD and amphetamine, were also reportedly used over the course of a typical evening. As already noted, combined alcohol and amphetamine use is relatively common, with up to 60% of those meeting diagnostic criteria for an amphetamine use disorder also meeting criteria for an alcohol use disorder (Burns & Teesson, 2002). Furr and colleagues (2000) found an association between alcohol intoxication and methamphetamine smoking, and suggested that heavy drinkers may use amphetamine to counteract the performance deficits caused by alcohol consumption. Reports of concurrent use of cannabis and benzodiazepines have also been commonly found among amphetamine users (Baker et al., 2004).
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Methamphetamine and ecstasy are increasingly used in combination, yet little is known of the effects of this combination. Clemens and colleagues (2004) recently conducted research with rats to investigate the behavioural, thermal and neurotoxic effects of MDMA and methamphetamine when given alone or in combined low doses. The researchers concluded that these drugs used in combination may have greater adverse acute effects, including acute head-weaving (moving head from side to side) and hyperthermia, and long-term effects, including decreased social interaction, increased emergence anxiety and dopamine depletion, than equivalent doses of either drug alone. In a subsequent article summarising the research to date, Clemens and colleagues (2007) reported that animal models suggest: a tendency for more compulsive use of methamphetamine over MDMA; unique pro-social effects of MDMA; modulation by high temperatures in the rewarding effects of both drugs; functional and emotional impairments associated with both drugs; and likely synergistic adverse effects when used in combination.
Polydrug use was one of the themes that emerged from the consultations. The impact of polydrug use, particularly alcohol use in conjunction with ATS, was raised as a potential contributor to ATS related aggression and violence. At one of the consultations it was noted that polydrug use was prevalent in rural and remote communities, in particular the use of illicit drugs with alcohol. There was consensus and considerable concern that polydrug use had a significant impact on treatment outcomes. Polydrug use could also contribute to shifts in patterns of drug use. For example, a number of participants expressed concern that attempts to manage ATS problems might ‘shift the problem to use of other drugs’. A written submission from the Australian Drug Foundation (ADF) highlighted the development of new forms of drugs in response to effective law enforcement measures that would require:
a quick response, early warning information system to circulate information to those who need it most; the users and frontline health and emergency staff.
Driving risk
Drug driving is generally accepted as:- driving under the influence of alcohol or any other drug to the extent that one is unable to demonstrate appropriate control over a motor vehicle (Davey et al., 2005, p.62).
As reviewed by Sheridan and colleagues (2006), injury associated with methamphetamine use is most commonly related to driving and violence. A number of Australian studies were reviewed including a 10-year multi-centre study conducted by Drummer and colleagues (2003). This research, of drugs in drivers killed in Australia, found that 4.1% of the 3398 cases had stimulants in their blood. Furthermore, while only 3.4% of car drivers tested positive, 23% of truck drivers tested positive to stimulants.
The National Drug Law Enforcement Research Fund (NDLERF) recently funded a largescale prospective study of the incidence and severity of drug- and alcohol-related trauma in South Australia, including driving-related trauma (Griggs et al., 2007). Samples were taken from trauma patients presenting to the Royal Adelaide Hospital Trauma Service or Emergency Department. Across the two hospital groups, motor vehicle crashes were the leading cause of presentation to the hospital following trauma, accounting for 70.2% of presentations. Among these, 38.4% were positive for alcohol or other drugs. Meth/ amphetamine was found in 6.9% of injured car drivers.
Of police detainees who self reported driving during the 12 months prior to detention, 55% stated they had driven following the use of illicit drugs, with 30% reporting driving after the use of meth/amphetamine (Mouzos et al., 2006). Of these, 58% had used cannabis and 50% had used amphetamine and driven at least once a week after using the drug. An increase in the incidence of drug driving was associated with a decrease in the incidence of drink driving. Many reported uncertainty about the legality of drug driving (52% were unlicensed), were generally unconcerned about driving, and were not deterred from driving through fear of detection. Just under a quarter (22%) believed amphetamine had a positive effect on driving compared to 15% for cannabis and 7% for heroin (see Table 3.1). Nicholas (2003) suggests that meth/amphetamine users may be attracted to police pursuits for the same reasons they use the drugs - a desire for excitement and risk-taking behaviour and raised levels of aggression.
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Table 3.1: Perceptions of adult police detainees of the effects of drug use on their driving
Source: AIC, DUMA collection 2006
The 2004 NDSHS found that of Australians aged 14 years and over who had used illicit drugs in the past 12 months, one in four (23%) had driven a motor vehicle after they had used illicit drugs (Australian Institute of Health and Welfare, 2005a). This was more common for males than females. In contrast, one in six persons (16.1%) had driven a motor vehicle after they had consumed alcohol (translating to 2.2 million people, consisting of approximately 1.5 million males and 0.7 million females).
The 2006 EDRS reported that of those who had driven a car in the previous six months, 77% had driven within one hour of taking an illicit drug on at least one occasion (Dunn et al., 2007). Of these, 78% reported driving after taking ecstasy, 34% after amphetamine (‘speed’), 26% after crystal methamphetamine, and 15% after base methamphetamine. Participants who had driven a car in the preceding six months were asked to indicate how impaired a person’s driving ability would be under the influence of various drugs. For ecstasy, the majority indicated that driving under the influence of ecstasy would carry a ‘moderate risk’ (42%) or ‘high risk’ (31%). For methamphetamine, the majority indicated that driving under the influence of methamphetamine would carry a ‘low risk’ (36%) or ‘moderate risk’ (26%).
The 2006 IDRS also enquired about driving risk behaviour and of those who had driven recently, 78% reported driving after taking an illicit drug (O’Brien et al., 2007). Among this group, 30% reported driving after taking speed, 23% after crystal methamphetamine and 14% after base.
Several jurisdictions have now introduced random roadside drug testing and comments were made in reference to this during consultations. Specifically, this was noted as providing an opportunity to deter drug impaired driving and for ATS early interventions. ATS are among the most common drugs identified in road-side drug testing and it is likely that many people thus identified (e.g., youth out late at night, transport industry staff) might not otherwise come into contact with health and community services.
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Sexual behaviour
ATS, and particularly methamphetamine, have been linked with increased libido and decreased disinhibition. Among those in the 2006 EDRS who reported engaging in penetrative sex, the majority (85%) reported using drugs during sex in the previous six months (Dunn et al., 2007). Among this sample, 83% reported using ecstasy, 18% reported speed use and 16% reported use of crystal methamphetamine on these occasions. Use of protective barriers during sex when combined with drug use was similar to protective use in general, and more common with casual (50%) than regular (19%) partners.Molitor and colleagues (1999) compared the sexual risk behaviour among a sample of injecting methamphetamine users to injecting drug users never using methamphetamine. Results indicated that male methamphetamine injectors had more sex partners and participated in more acts of anal intercourse with casual partners and vaginal intercourse with regular and casual partners than their counterparts. Female methamphetamine injectors engaged in more acts of vaginal intercourse with regular partners than their counterparts. Furthermore, male methamphetamine injectors reported trading sex for money or drugs, and were less likely to use condoms than their counterparts. Lastly, methamphetamine use also correlated with using shared needles or syringes and not always disinfecting needles or syringes.
Heterosexual ATS users have been reported to engage in more risky sexual behaviours including multiple sexual partners, anonymous partners and unprotected sex (Lineberry & Bostwick, 2006). In a study exploring sexual risk behaviours among a sample of 139 HIVnegative, heterosexual methamphetamine users, participants reported using condoms for vaginal sex about one third of the time (Semple et al., 2004). In contrast, condoms were used for anal sex about one quarter of the time, and 7% of the time for oral sex. A United States study examining the sexual behaviours of 1011 males found 15.6% reported recent or past methamphetamine use (Krawczyk et al., 2006). Recent methamphetamine users were more likely to have casual or anonymous female sex partners, multiple partners, partners who injected drugs, and received drugs or money for sex with a male or female partner. However, while there is evidence for a link between methamphetamine dependence and unprotected sex, McKetin and colleagues (2005) argued that this may be due to the associated lifestyle of these persons rather than due directly to the pharmacological effects of methamphetamine.
There is proportionally more research into sexual risk behaviour and methamphetamine use among homosexual populations. Research in the United States suggests that methamphetamine use is endemic to urban gay and bisexual men (Halkitis et al., 2001). Research also consistently shows an association between methamphetamine use and HIV infection, likely to be a result of the high-risk sexual behaviours in conjunction with the drug use (Reback, 1997; Worth & Rawstorne, 2005). In Australia, figures from the Sydney Gay Community Periodic Survey 1996-2005 reported that 20% of gay men in Sydney had used crystal methamphetamine in the previous six months (Hull, Rawstorne et al., 2006a). In Queensland, Melbourne and Perth, the rate among gay men is reportedly lower, at between 12-16% (Hull, Brown et al., 2005; Hull, Prestage et al., 2006; Hull, Rawstorne et al., 2006b).
Shoptaw and Reback (2007) reviewed the available literature on the epidemiology of methamphetamine use in men who have sex with men (MSM), methamphetamine use and risk behaviours for sexually transmitted infections and potential interventions to prevent and respond to these risks. It was found that methamphetamine use was highly prevalent in MSM and there were strong associations observed between methamphetamine use and HIV-related sexual transmission behaviours. Behavioural treatments, from brief interventions to intensive out-patient treatments, produced sustained reductions in methamphetamine use and concomitant sexual risk behaviours among methamphetamine-dependent MSM.
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While more research has been conducted into methamphetamine use among homosexual populations, few studies have directly compared methamphetamine users according to sexual orientation. A study conducted in Sydney compared homosexual/bisexual male and female regular ecstasy users with their heterosexual counterparts to determine whether patterns of drug use or risk differed across these groups (Degenhardt, 2005). It was found that self-reported risk behaviours such as unprotected sex and needle sharing (among injectors) did not differ according to sexuality. However, homosexual/bisexual men and women were significantly more likely than heterosexual men and women to report a greater number of sexual partners and higher rates of injecting drug use.
Increased risk-taking behaviours related to ATS use were raised as an issue during consultations. Particular mention was made of sexual health and concerns raised over the transmission of sexually transmitted infections (STIs).
Aggression and violence
Most research linking ATS drugs with aggressive and violent behaviour has focused on its association with methamphetamine. The impact of methamphetamine use on neurochemical brain systems is thought to underlie the relationship with aggression. A recent study by Sekine and colleagues (2006) found that chronic methamphetamine users had higher levels of aggression that non-drug using controls and decreased levels of serotonin in areas of the brain involved in the regulation of aggression. However, serotonin depletion is more often documented in relation to ecstasy use than methamphetamine and little evidence has been found for a relationship between ecstasy use and aggression. Methamphetamine is more often implicated in regulation of dopamine and in this regard, may relate to aggressive behaviour via the ‘fight-or flight’ response of the sympathetic nervous system (Haller,Makara & Kruk, 1998).
Several studies have found high levels of aggressive behaviour among regular meth/amphetamine users (Hall et al., 1996; Sommers & Baskin, 2006; Wright & Klee, 2001; Zweben et al., 2004). The 2006 IDRS (O’Brien et al., 2007) asked participants about drugrelated aggression. Verbal aggression following the use of alcohol/other drugs was reported by 33% of the sample and physical aggression by 13%. For both of these behaviours, various formulations of methamphetamine were by far the most common drugs reported as being consumed prior to aggression. For those who had been verbally aggressive, 46% reported taking a form of methamphetamine and for those who had been physically aggressive, 49% reported taking a form of methamphetamine.
Police detainees charged with violent offences were not more likely to test positive to methamphetamine than those charged with other forms of offending (Smith, forthcoming). However, heavy or dependent ATS users were more likely to have a history of violent offending. The number of times ATS dependent users were charged with a violent offence in the past 12 months was higher than those detainees not dependent on ATS. Furthermore, it was found that violent detainees dependent on ATS had greater contact with the criminal justice system through arrest or imprisonment than other violent detainees. More specifically, of all violent offenders, aggravated robbery offenders were most likely to report ATS dependence, were more likely to indicate that all of their offending was drug related, and were most likely to have spent time in prison in the past 12 months.
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A significant difficulty in disentangling the links between meth/amphetamine and violent crime is polydrug use. In attempting to disentangle polydrug use and violent crime, analysis of the drug using histories of incarcerated male offenders found that those who were regular users of both heroin and amphetamine had the highest likelihood of involvement in violent crime, followed by those who were regular amphetamine users, and then regular heron users (Makkai & Payne, 2003, see Table 3.2). Those who were not regular users of either drug had much lower probabilities of involvement in violent crime and lower frequency of offending.
Table 3.2: Violent offending histories for regular amphetamine and heroin users, adult male prisoners (%)
Source: Australian Institute of Criminology, DUCO Male Survey, 2001
It has also been speculated that the relationship between violent behaviour and methamphetamine use is related to psychosis. Recent studies in Sydney found that methamphetamine users reported experiencing overt hostility during psychosis (McKetin, McLaren & Kelly, 2005), and in another study, half those who experienced psychotic symptoms in the past year reported feeling hostile or aggressive at the time, and one quarter exhibited overt hostile behaviour (McKetin et al., 2006a).
McKetin and colleagues (2006b) reviewed the existing literature and concluded that it is not clear whether violent behaviour among chronic methamphetamine users can be attributed directly to methamphetamine use or to co-occurring factors, such as concomitant alcohol use, psychiatric status and lifestyle factors. The authors found that research was limited by a failure to distinguish between economically motivated violent crime and assaults, and lack of controls for personality and lifestyle factors. However, the authors stated that while there is currently insufficient evidence to indicate a direct causal relationship between methamphetamine use and violence, the evidence for this relationship appears strongest in the context of methamphetamine-induced psychosis.
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