Associations between opioid dependence and sweet taste preference

Rationale Past research suggests that people with opioid dependence show increased consumption of sweet food, but it is unclear if this is influenced by altered taste preference and/or taste perception. Objectives We tested whether people prescribed opioid substitution therapy (OST) exhibited a shift in preference towards sweeter flavours, and altered perception of sweetness, and explored whether these measures of taste preference/perception were associated with measures of opioid use. Methods Three groups of participants (people prescribed OST, n=36; people with past opioid dependence, but now abstinent from all opioids, n=18; and controls with no history of substance dependence other than nicotine, n=29) provided ratings of "sweetness", "liking", and "desire" of 4 solutions with varying concentrations of sucrose. Results We did not find significant differences between groups in the effect of sucrose concentration on "sweetness", "liking", or "desire" ratings. However, among those prescribed OST, frequency of recent illicit opioid use was associated with reduced perception of "sweetness" of low sucrose concentrations. Higher methadone dose was associated with a shift towards liking sweeter concentrations. Among those with past opioid dependence, longer duration of abstinence from opioids was associated with a shift towards liking sweeter concentrations. Conclusions Among people currently dependent on opioids, reduced sensitivity to low levels of sweetness and increased preference for sweeter flavours may be associated with increased dependence on opioids. Among those who have ceased opioid use, the association between preference for sweeter flavours and duration of abstinence is a novel finding that deserves further investigation.