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[Contents][Appendix 1]
[Reference 156][Reference 158]

E is for Ecstasy by Nicholas Saunders

Appendix 1: Reference Section

157 Serotonin Neurotoxicity after MDMA: A Controlled Study in Humans by George Ricaurte et al. 1994 Neuropsychopharmacology in press.

Whether or not MDMA is neurotoxic in humans has not been established, though it is known to cause damage to brain serotonin neurons in experimental animals.

30 MDMA users and 28 controls matched for weight, height, education and other drug use were admitted to a controlled inpatient setting after at least 2 weeks abstinence. On average, they had taken 170mg doses of MDMA weekly on 95 occasions over 5 years. As there is no method for detecting serotonergic neurotoxicity in the living human brain, an indirect method was used consisting of measuring the concentration of 5-HIAA in spinal fluid. Previous studies in monkeys had established a relationship between serotonergic neurotoxicity and concentration of 5-HIAA in spinal fluid. Assessments were also made of pain endurance since serotonin has been associated with pain. In addition, personality assessments were made and compared with the control group.

Results showed that MDMA users had lower levels of 5-HIAA, implying their serotonin levels were lower. However, there was no significant correlation between 5-HIAA levels and number of uses of MDMA; nor duration or frequency of use, nor time since last MDMA exposure. It is suggested that trials are made among users of fenfluramine, which is "taken by more people and more frequently than MDMA, and is highly toxic to 5-HT neurons in non-human primates" produces similar results.

There was no difference in pain endurance between MDMA users and controls. Personality measurements showed statistically significant differences between MDMA users and controls: MDMA users were assessed as "less impulsive, more harm-avoidant, and have decreased indirect hostility". This was unexpected, since it had been previously assumed that lower serotonin levels corresponded to increased impulsive aggressive behaviour. Alternative explanations for these findings were discussed and dismissed as unlikely.

Conclusions:

1. The finding that spinal 5-HIAA levels were lower in MDMA users, and therefore by implication also brain serotonin "may reflect MDMA neurotoxicity" in users. The supposed toxicity was greater in women, which may have been due to them having higher concentrations through being smaller or using the drug more frequently.

2. The findings that MDMA users were less impulsive, more harm-avoidant, and have decreased indirect hostility supports the notion that these personality characteristics are modulated by serotonin.


[Contents][Appendix 1]
[Reference 156][Reference 158]
E is for Ecstasy by Nicholas Saunders (contact@ecstasy.org)
HTMLized by Lamont Granquist (lamontg@u.washington.edu)