Methamphetamine CBM Pilot
Many people relapse after treatment for dependence on methamphetamine (often known as ‘ice’, ‘meth’). There are likely to be many reasons for this, but one factor that is believed to cause relapse is “approach bias”. “Approach bias” refers to the way in which we are automatically drawn to approach or seek things we find rewarding when we encounter signals (like sights, sounds, smells, or places) that remind us of those things. When people use drugs frequently, they often develop an approach bias related to that drug, so that sights (like seeing drug-related paraphernalia, or people they have used drugs with), places they have used drugs, or other signals automatically spur their desire to approach or seek drugs … and then use them.
Approach bias can be triggered very quickly, and may function at a somewhat subconscious level, so people aren’t even fully aware they’re being influenced by it. This can make it difficult to control. However, in recent years, researchers have developed computerised training programs called “approach bias modification” (ABM), where people repeatedly practice responding to drug-related pictures in a way that can reduce their approach bias. So far, the only large clinical trials of ABM in addiction have been for alcohol and tobacco, and have shown that repeated sessions of ABM can reduce the likelihood of relapsing after being treated for alcohol dependence. However, for illegal drugs, there has only been a small trial with people wanting to reduce their cannabis user, and no studies of ABM for methamphetamine dependence.
Before trying to run a large trial to test whether ABM would be effective for people trying to stop using methamphetamine, we decided to test whether it would be feasible to conduct a 4-session programme of ABM training during residential withdrawal treatment (i.e. ‘detox’). We also wanted to see whether ABM would be acceptable to methamphetamine withdrawal patients (since ABM involves responding to drug-related pictures, which may be triggering or distressing to some). This study was run at Wellington House, Depaul House, and Windana Drug and Alcohol Recovery by researchers from Turning Point, Monash University, and Deakin University, with funding from the Eastern Health Foundation.
We found that recruitment for this research was more difficult than we expected. Only 47% of the 99 patients we invited to participate agreed to join the study and commenced ABM training. Of the 47 who commenced ABM training, 62% completed all 4 sessions. This suggested that feasibility was limited during withdrawal treatment.
However, acceptability was good among those who did participate. Very few (9%) withdrew due to feeling triggered by the training. While the first session of ABM often caused some increase in cravings, cravings generally reduced over the course of the training. When asked to rate the ABM training, 78% of participants indicated that they ‘agreed’ or ‘strongly agreed’ that the task was interesting, and 36% felt it had reduced their craving for methamphetamine.
We also did follow-up interviews 2 weeks and 3 months after participants left withdrawal treatment. We managed to contact 31 participants for the 2-week follow-up and 26 for the 3-month follow-up. A majority of participants reported being abstinent from methamphetamine at each follow-up (61% at the 2-week follow-up and 54% at the 3-month follow-up), which is higher than the usual rates of abstinence seen after withdrawal treatment.
The acceptability and abstinence findings were encouraging, and so we hope to commence a larger project to better test how effective ABM is for people seeking to quit methamphetamine. However, our finding regarding feasibility suggests that acute withdrawal treatment may be too early for many patients to participate. Clients often experience withdrawal symptoms such as extreme fatigue, excessive sleep, and emotional instability during these initial days of withdrawal, and this seemed to contribute to the difficulty recruiting participants and completing training. We therefore intend to conduct our next trials in settings where clients may be more stabilised, such as residential rehabilitation.