Harmful or hazardous alcohol use is endemic among young people in the developed world [1–3]. In Australia, 60% of young people over a 12-month period reported drinking at levels placing them at risk of harm, with up to 30% drinking at levels placing them at weekly or greater risk of injury . Hazardous alcohol use is a major preventable cause of injury, disability and death in young people, as well as a range of adverse mental health, social, educational, vocational and legal outcomes . It is estimated to contribute to 27.5% of all deaths and 19.5% of substance-attributable disability-adjusted life years among 15–29-year-olds in the developed world . In 2009, the economic burden of alcohol was estimated to equate to 0.45-5.44% of Gross Domestic Product (GDP) across 12 countries . In Australia alcohol use represents 1.2% of GDP costing the economy $15 billion annually .
The rate of alcohol-related emergency department (ED) presentations in young people has increased dramatically in recent decades [7–9]. This presents a unique opportunity to engage traditionally non-treatment seeking youth into brief alcohol treatment. However, EDs are not ideal settings for the delivery of psychological treatments. Medical treatment for the injury or illness must take priority, and patients’ attention may be impaired by intoxication, distress or the administration of analgesics. An opportunistic intervention involving initial engagement in these settings, followed by delivery of a post discharge telephone-based intervention benefits both acute management and longer term treatment engagement. Global mobile devices and connections grew to 7 billion in 2013 . Ninety-nine percent of young Australians own mobile phones, and overwhelmingly prefer electronic sources of health information over traditional ones [11, 12]. Mobile phones provide an innovative, youth friendly and accessible way of delivering treatment.
Brief interventions (BIs) have a well established evidence-base for reducing alcohol use and related harm in adults [13, 14], including adults presenting to EDs with alcohol-related injuries . They typically comprise 1-2 sessions (from 10-15 minutes to 2 × 1 hour sessions) of personalised assessment feedback and information (AF/I). Many BIs include motivational interviewing, a person-centred therapeutic approach designed to assist individuals resolve ambivalence about problem drinking, set tangible goals for and strengthen commitment to change .
There is strong evidence for the impact of brief motivational interviewing interventions (MI) on young college students’ alcohol use and related problems at 3 [17–19], 6, 12, 24 and 48 months follow up, compared with no treatment [20, 21]. One study has reported positive effects for MI on alcohol use and related problems among adolescents presenting to an ED with alcohol-related injuries at 3 and 6 month follow up, compared to standard care brief advice; .
While MI produces demonstrable reductions in alcohol use and related harm, there is significant scope to increase their impact. Most studies comparing MI and no treatment control conditions report small to moderate differences in alcohol use outcomes [20, 21]. One reason for this is that treatment effects tend to reduce over time, as young people in control groups also begin to address their alcohol misuse [21, 23].
It is unclear which form of BI is most effective for treating youth alcohol misuse as many studies report small effect sizes when comparing MI with other types of BIs. For example, while Monti et al.
 reported ED-based MI was more effective for reducing alcohol use at 6 and 12 months follow up than assessment feedback alone, only small differences in effect size (f’s ranging -.24 to -.33) were found. We recently found two sessions of MI had more impact on alcohol use than an AF/I control at 1 (f = -.62) and 3 months (f = -.51) but not 6 month (f = -.47) follow up, in young people accessing a youth primary care service . However, two further studies comparing MI with AF/I in college students at 6 and 12 month follow up, did not find superiority for MI [26, 27].
Recent theoretical and empirical advances provide new insights into how to increase the impact of BIs for youth alcohol misuse. Most addiction theories focus on two major sources of reinforcement for substance misuse: (i) positive reinforcement linked to the pleasurable effects of substance use and (ii) negative reinforcement, linked to the relief of negative affect or withdrawal symptoms [28, 29]. Personality risk models of substance use provide one way of understanding individual differences in susceptibility to drug reinforcement. Different personality traits have been shown to be reinforcement-specific, and are related to different patterns of substance misuse , distinct motivations for substance use [28, 29, 31] and differential sensitivity to alcohol reinforcement [32, 33]. Four personality risk factors for youth substance misuse namely: (i) anxiety-sensitivity/proneness; (ii) depression-proneness; (iii) impulsivity-reward dependence; and (iv) sensation seeking, have been shown to differentially predict susceptibility to binge drinking, alcohol-related problems, illicit drug use and coping and enhancement motives for substance use in young people . Anxiety proneness is a fear of anxiety-related bodily symptoms and has been linked to alcohol misuse and related problems in young adulthood, via a negative reinforcement process where alcohol is used to reduce anxiety symptoms and negative affect [34–37]. Depression-proneness links with drinking to cope with depression-specific emotions and is associated with early onset alcohol and drug problems [30, 38]. Impulsivity or a tendency to act without thinking is associated with early onset and problematic alcohol and other drug use, as well as a range of other externalizing problems including antisocial and sexual risk-taking behaviors [38–44]. Sensation seeking or the need for intense pleasurable experiences, has the strongest links with alcohol misuse (especially binge drinking) and other drug use [45–47], and drinking for enhancement reasons via positive reinforcement processes [28, 29, 31].
Increasing evidence for a personality risk model of alcohol misuse has resulted in the development of brief personality-targeted interventions (PI), which differentially target the motivational pathways to alcohol misuse underlying these four personality dimensions. Conrod et al.  developed and evaluated the first brief PI incorporating psychoeducation and motivational and cognitive behavioral coping skills training among female adult substance users. This 90-minute BI was more effective for reducing alcohol misuse at 6 months, than a time-matched motivational film/supportive discussion or a mismatched intervention targeting another personality profile. Similarly, brief (3 x 1-hour sessions) group cognitive behaviour therapy targeting anxiety sensitivity in female students reduced hazardous alcohol use, conformity and emotional relief alcohol expectations at 10 weeks follow up, compared to control group seminar on psychology ethics .
Conrod et al.  developed a school-based group version (2 × 90 minute sessions) of PI, providing cognitive behavioral coping skills training targeting the motivational processes linking the adolescents’ dominant personality style to alcohol use. Three separate randomized controlled trials (RCTs) have demonstrated the efficacy of this approach for reducing the rates of alcohol use, binge drinking and alcohol-related problems, compared to no treatment at 4, 6[46, 50], 12 and 24 month follow up [38, 51]. This intervention also reduced growth in the quantity/frequency of alcohol use over time periods of up to 24 months, lessened the uptake of illicit drug use and reduced alcohol enhancement and coping motives at 24 months [38, 51]. However, research is yet to determine the efficacy of PIs in young people with alcohol and/or illicit drug misuse, or compare its efficacy to other active BIs for alcohol misuse.