A recent open label study found some support for the effectiveness of a Risperidone injection, given once every 2 weeks, in reducing crystal meth (speed) use.
The 22 patients who participated reduced their weekly crystal meth use from an average of 4 times per week to only 1 time per week. The difference between those who were able to stay completely clean and the others seemed to have to do with the levels of Risperidone in the blood.
The nice thing about using an injection as addiction treatment is that it removes the possibility of patients choosing not to take their medication on any given day. Such non-adherence to treatment is very often found to be the reason for relapse.
This study will need to be followed up by placebo-controlled double-blind studies, but given Risperidone’s action as a Dopamine antagonist, I suspect that those trials will also show a strong treatment effect. The promise of medicines as addiction treatment cures always seems great, but I believe that at best, they can be an additional tool to be used in conjunction with other therapies.
The question will be whether the side-effects common with antipsychotic medication will be well-tolerated by enough people to make the drug useful for addiction treatment.