Effects of trifluoromethylphenylpiperazine (TFMPP) on interhemispheric communication

Abstract

'Party Pills' containing trifluoromethylphenylpiperazine (TFMPP) and benzylpiperazine are legally available in many countries and marketed as safe alternatives to other illicit substances such as methamphetamine and methylenedioxymethamphetamine (or Ecstasy). They have gained huge popularity around the world, especially amongst young adults. However, there is no information currently available describing the acute neurophysiological effects of these psychoactive drugs in humans. The purpose of this study is to investigate the effects of TFMPP on central information processing speed in humans. A randomised, double blind, placebo-controlled study using electroencephalography (EEG) was carried out to investigate the effects of TFMPP on interhemispheric transfer time (IHTT). Healthy, right-handed males (age: 25 ± 5.6 years) were given placebo (n = 15) or TFMPP (0.94 mg/kg, oral, n = 15) and tested both pre- and 2 h post-drug administration. High-density EEG recordings (128 channels which were re-referenced using an average reference to make 129 electrodes) were used to record event-related potentials. The N160 component was defined as the biggest negative peak in the range between 140 and 220 ms after the event. The IHHTs were analysed by deducting the N160 latency obtained in the contralateral hemisphere from the N160 latency obtained in the hemisphere ipsilateral to stimulus signal. Statistical analysis using a split-plot design analysis of variance revealed that TFMPP significantly reduced the IHTT but did not affect reaction time. No statistically significant changes were observed in the placebo group. This study is the first to report the neurophysiological effects of TFMPP in humans and suggests that TFMPP may affect transmitter systems involved in speeding of interhemispheric communication in the male brain.