Although amphetamine users experience significant harms associated with their use, help-seeking and treatment uptake is low. The aim of this thesis was to examine factors associated with amphetamine users’ decision to seek help, and in particular, whether online interventions are a feasible, acceptable, and effective approach to increasing treatment access for this population. This aim was achieved through a series of studies that examined perceived barriers to face-to-face and online treatment from the perspective of both amphetamine users and health professionals, and finally, the usability and pilot testing of an online intervention for the treatment of amphetamine use. Study 1 systematically investigated amphetamine users’ perceived barriers to online and face-to-face psychological treatment. It was predicted that online interventions would present fewer barriers compared to face-to-face treatment for this population. One hundred and twenty-two Australian amphetamine users completed measures about perceived barriers to treatment. Significant differences were found, in which fewer barriers were found for online compared to face-to-face treatment. Stigma was identified as the greatest barrier to both face-to-face and online treatment and availability of services was perceived as a greater barrier to online than face-to-face treatment. Attitudes toward the Internet were investigated and those who endorsed that it made sense to use the Internet were less likely to perceive barriers to online and face-to-face treatment. This study also investigated users’ preferences for receiving information and support via non-face-to-face formats. Users’ highest preferences for online support were for text/fact sheets, instant messaging to health professionals, and websites focused on wellbeing. Although the majority of users had Internet access, used the Internet daily, and held positive attitudes towards the Internet, many stated they were more likely to attend face-to-face than online treatment. These results suggest that more work is needed to make online interventions appealing to this population. Study 2A examined perceived barriers to face-to-face and online treatment for amphetamine users from the perspective of health professionals. Obtaining input from health professionals when developing interventions is recommended as service providers can provide additional insight into the difficulties, needs, and preferences of target populations. Sixty-seven Australian health professionals who reported currently or previously delivering treatment for amphetamine use completed measures about perceived barriers to face-to-face and online treatment for amphetamine users. Health professionals perceived fewer barriers to online compared to face-to-face treatment. Stigma was identified as the greatest barrier to both face-to-face and online treatment. Health professionals’ perspectives on amphetamine users’ preferences for receiving online support were also investigated. They identified video links to health professionals, online communities (forums or chat rooms), and websites focused on wellbeing as amphetamine users’ preferred methods for receiving information and support online. Access and attitudes toward the Internet and burnout were also investigated. Access to and attitudes toward the Internet did not impact upon perceived barriers to treatment or whether health professionals had looked online for treatment for their clients. Health professionals held positive attitudes towards the Internet. Supporting health professionals with high levels of depersonalisation (as an indicator of burnout) may be important for encouraging promotion of innovative treatments, as it was negatively related to professionals’ self-report of having investigated online treatment options for amphetamine users. Study 2B compared amphetamine users’ and health professionals’ perspectives on perceived barriers to treatment, attitudes towards the Internet, and preferences for receiving information and support via non-face-to-face formats. Understanding differences in perceptions between clients and health professionals is important as differences can impact on treatment retention and treatment outcomes. Both populations were confident using the Internet and there was no significant difference in attitudes towards the Internet. Health professionals perceived greater barriers to face-to-face treatment compared to amphetamine users. No significant differences were found for perceived barriers to online treatment and both populations identified stigma as the greatest barriers to both face-to-face and online treatment. Differences were found in regard to preferences for receiving information and support via non-face-to-face formats. Health professionals were more likely to indicate direct communication with a health professional as preferred compared to amphetamine users. Further investigation into differences in perspectives of health professionals and amphetamine users is warranted, particularly if health professionals are providing input into the development of interventions for amphetamine users. Study 3 investigated the usability of ‘Beating the Rush,’ an online psychological intervention for amphetamine use. Investigating usability prior to evaluating an intervention is recommended to ensure that the website is designed in a way to maximise engagement as a lack of engagement can impact negatively on the effectiveness of the intervention. ‘Beating the Rush’ offered five 30-minute sessions of cognitive behavioural therapy with contingency management (vouchers for completion of online sessions and three- and six-month follow up assessments). Feedback about the usability of the site was sought from 10 amphetamine users and 11 health professionals. Overall, feedback about the usability of the intervention was positive and areas for improvement were identified, allowing researchers to improve some design features of the site to maximise engagement. Study 4 was a pilot test of the ‘Beating the Rush’ intervention in Australia. However, only 23 individuals registered for the program and all participants dropped out prior to completing the intervention. As such, the effectiveness of the intervention was unable to be investigated. However, a user's experience of the website is presented. Issues with engagement into, and dropout from online interventions has been found for interventions targeting a range of mental health difficulties and is not unique to the field of treatment for amphetamine use. Thus, issues with engagement into online interventions in general were identified and opportunities to enhance engagement were presented. Due to the broad nature of issues with engagement into online interventions and more specifically, the low uptake of treatment by amphetamine users, identifying and evaluating innovative strategies aimed at encouraging help-seeking and treatment engagement, and developing interventions that better meet the needs of individuals is an important focus for future research and clinical practice.