A single dose of MDMA (75 mg) transiently impairs immediate and delayed verbal recall during the intoxication phase (1.5–2 hours after dosing), but no residual memory impairment is present during the withdrawal phase (25.5–26 hours after dosing). In a double-blind, placebo-controlled crossover trial with 18 recreational MDMA users, methylphenidate (20 mg) showed no effect on memory or mood at any time point. During MDMA withdrawal, participants reported more fatigue and less vigor but no depressive symptoms. The findings indicate that MDMA directly causes short-term memory deficits, but these effects are not long-lasting.
Combining mephedrone with alcohol amplifies cardiovascular effects and intensifies euphoria and well-being compared to either drug alone, while mephedrone reduces the sedative effects of alcohol. In a double-blind, placebo-controlled trial with 11 male volunteers, the combination increased blood pressure, heart rate, and subjective feelings of euphoria. Mephedrone alone and alcohol alone were also tested. The results suggest that the abuse liability of mephedrone is greater when taken with alcohol, similar to other psychostimulants like amphetamines and MDMA.
In the first human study of 3-methylmethcathinone (3-MMC), a synthetic cathinone designer drug, 14 participants received escalating doses of 25, 50, and 100 mg in a placebo-controlled crossover trial. The drug caused dose-dependent increases in heart rate and blood pressure that were not clinically significant, along with subjective feelings of being high. 3-MMC also enhanced performance across several neurocognitive domains, including processing speed, cognitive flexibility, psychomotor function, attention, and memory, without affecting impulse control. Participants reported mild dissociative and psychedelic effects, decreased appetite, and transient increases in drug liking and wanting. The cardiovascular and psychostimulant profile resembles amphetamine-related compounds. Low to moderate doses were well tolerated and safe, with potential health risks likely only at high or excessive doses.