Discussion
Taken together, and consistent with initial clinical findings, our study suggests that methylone may have potential for treating depression and anxiety.
Methods
For all studies, 6-8-week-old male Sprague Dawley rats (N = 6-16) were used. We employed the Forced Swim Test (FST), a classic and widely used screen for antidepressants, to explore the effects of methylone and to probe dose-response relationships, durability of effect, and potential interactions with combined SSRI treatment. We compared the effect of methylone with the prototypical SSRI fluoxetine.
Results
Three doses of fluoxetine (10 mg/kg) given within 24 h before FST testing caused a 50% reduction in immobility compared with controls that lasted less than 24 h. In contrast, a single dose of methylone (5-30 mg/kg) administered 30 min prior to testing produced a rapid, robust, and durable antidepressant-like response in the FST, greater in magnitude than fluoxetine. Immobility was reduced by nearly 95% vs. controls and effects persisted for at least 72 h after a single dose (15 mg/kg). Effects on swimming and climbing behavior in the FST, which reflect serotonergic and noradrenergic activity, respectively, were consistent with studies showing that methylone is less serotoninergic than MDMA. Fluoxetine pretreatment did not change methylone's antidepressant-like effect in the FST, suggesting the possibility that the two may be co-administered. In addition, methylone (5-30 mg/kg) exhibited anxiolytic effects measured as increased time spent in the center of an open field.
