Reported adverse effects of taking MDMA include anxiety, depression and sleep disorders such as insomnia. These however are disputed due to the fact that there is no conclusive evidence that MDMA itself actually causes these problems. [6] It is also known, from previous physiological tests, that MDMA damaged serotonin neurons in animals, some of which were non-human primates. [2][3] This is why it is thought that MDMA may cause the same problems in humans. Other studies carried out have shown that long-term ecstasy use causes impairment to verbal and visual memory. The aim of this report is to examine expert studies in this field and determine whether MDMA does in fact cause any damage to the human brain.
Results.
MDMA is known to cause damage to serotonin transporters in the brains of animals, including non-human primates such as baboons. [2]-[4] Therefore, there has obviously been speculation that it causes the same problems in the human brain. Some studies, including the ones being discussed have concluded that MDMA causes damage and reduces the number of serotonin transporters in the human brain after long-term use.
The first study was investigating serotonin neurones in MDMA users. Twenty-nine test subjects were gathered, 14 of whom had previously used ecstasy heavily and 15 who had never used the drug (controls). The 14 users had been abstaining from using the drug for 3 weeks and were drug tested before the experiments commenced using urine and blood samples. The test subjects were also paid after the drug test to ensure they hadn’t actually taken anything. A technique called positron emission tomography (PET) was used along with a carbon-11, which is a radioligand which labels serotonin transporters within the brain, so they become visible to the scan. [2] The scans were taken between one hour and an hour and a half after a tracer was injected to track the binding of the [11C]McN-5652 (the ligand which binds to the serotonin transporters).
Above are the brain scans from one control subject and an MDMA user. It clearly shows that the non-user has much higher binding activity and therefore more serotonin transporters within the brain. This contrast was shown throughout the test subjects and it is consistent with previous studies done on the action of MDMA on serotonin transporters in animals. These results, however, did not show differences in users who had been off the drug for different periods of time. [2]
This graph highlights the difference in binding of [11C] McN-5652 to serotonin between non users and progressively higher users. It clearly shows a correlation between the level of MDMA use and the binding activity on the serotonin transporters. This suggests that MDMA users on average have a lower concentration of serotonin transporters. Age and sex had no noticeable effect on the results. [2]
As the test subjects had to abstain from taking drugs for 3 weeks before the scans, the global deficits in serotonin transporters observed in the MDMA users was were not because of physiological effects of MDMA or other drugs. [2] This study concluded that MDMA users are at risk of affecting their brain in that it diminishes the concentration of serotonin transporters. It is known that serotonin is important in humans’ emotional development and in functions such as memory etc. By affecting these concentrations, users are at risk of developing memory problems and mental conditions such as depression. [2] There have been several accounts that long term use causes psychological problems including one instance, when a 26 year old male who had used ecstasy over 4 years and experiences psychological problems. He stopped using MDMA, however, after seven years abstinence, his mental condition hadn’t improved. [8] Psychological damage in baboons has also been recorded, well over a year after they had been given MDMA. [2]
Another study conducted regarding the affects caused by MDMA use is an experiment on memory impairment. 48 test subjects were used, 24 MDMA users and 24 non-users. All subjects abstained from recreational drugs for 2 weeks prior to the test to remove the possibility of drugs affecting test results. [3] This 2 week abstinence was confirmed by blood and urine screens.
The tests included were the Wechsler Memory Scale-Revised (WMS-R) which is composed of 13 parts, each measuring different aspects of memory, the Rey-Osterrieth Complex Figure(RCF),a visual memory test, and the Rey Auditory Verbal Learning Test (RAVLT), a verbal memory test. The Wechsler Adult Intelligence Scale was also used to test verbal ability. These memory tests were sorted into 4 criteria. These were immediate verbal memory, immediate visual memory, delayed verbal memory and delayed visual memory. [3]
This shows the relation between MDMA dose (100mg = one ecstasy tablet) and delayed visual memory for low vocabulary (circles) and high vocabulary (squares) groups. When z = 0, this represents the mean performance of the control group, therefore, the lower the score, the poorer the performance. [3]
This experiment concluded that users of MDMA have poorer scores in visual and verbal memory, and also that higher doses of MDMA shows progressively lower results in these tests. In the subjects, reductions in CSF 5-hydroxylindoleacetic acid, which tracks serotonin function in the brain, were shown. These results were gathered by liquid chromatography. [3] These types of impaired memory symptoms are also prevalent in former heavy ecstasy users, which enhances the evidence that ecstasy does cause long term damage with regards to memory functions. [8]
Discussion.
It is known that MDMA causes problems in the production of serotonin in non-human primates, which share a lot of the same physiology as humans. [2][3][9] This has hit the science world with mixed views, with sceptics believing that because MDMA is an illegal substance, some scientists have already made up their mind about MDMA, selectively using experiments and evidence that does show ecstasy to have adverse effects, but discounting reports which show the contrary. [5] Most of the scientific studies, however, conclude that methylenedioxymethamphetamine does cause brain damage in one form or another. It has been reported that it causes psychological problems as well as problems in memory. It is well publicised that MDMA causes a drop in the level of serotonin transporters which assist in functions such as memory and emotional stability in the short-term. [2]-[9] But there is much less evidence that it causes long-term damage, however there are a few reports that show psychological effects and memory deficiencies 7 years after heavily using the drug. [8]
The adverse effects are also disputed because of the proposed clinical uses of the drug. Some people believe that the benefits could potentially outweigh the benefits, such as in the treatment of Parkinson’s disease. It is reported to reduce the tremors in Parkinson’s sufferers which can make day-to-day tasks almost impossible. [10]
Despite the possible benefits, there is no doubt that MDMA cause’s damage to serotonin transporters in the human brain, as well as long-term damage (>1 year) in non-human primates. As it affects important chemical transporters such as serotonin, it could have the ability to cause emotional damage and cause mental illnesses, and physical damage such as memory loss. The fact that some of humans’ closest relatives suffer long term damage and some humans have also suffered long-term damage, the damage to primates should be used as reliable evidence that MDMA causes serotonergic neurones to be damaged.
References.
1. Freudenmann R. W., F. Oxler, S. Bernschneider-Reif. 2006. The origin of MDMA (ecstasy) revisited: the true story reconstructed from the original documents. Addiction 101(9): 1241-45.
2. McCann, U. D., Z. Szabo, U. Scheffel, R. F.Dannals, G. A. Ricaurte. 1998. Positron emission tomographic evidence of toxic effect of MDMA (“Ecstasy”) on brain serotonin neurones in human beings. Lancet 352: 1433-37.
-
Bolla, K. I., U. D. McCann, G. A Ricaurte. 1998. Memory impairment in abstinent MDMA (“Ecstasy”) users. Neurology 51:1532-1537.
-
Mathias, R. (NIDA NOTES Staff Writer). 1999. “Ecstasy Damages the Brain and Impairs Memory in Humans. NIDA NOTES. Vol 14: Number 14.
-
BBC NEWS website (Row erupts over ecstasy dangers), 2 September, 2002 ().
-
National Institute on Drug Abuse website (Facts about MDMA (Ecstasy)) November 1999 ().
-
Urban75 website (ecstasy: safety) 22 November, 1995 ().
-
Soar, K., A. C. Parrott, H. C. Fox. 2004. Persistent neuropsychological problems after 7 years of abstinence from recreational Ecstasy (MDMA): a case study. Psychol Rep 951(1): 192-6.
-
Ctoft, R. J., A, Klugman, T Baldeweg, J. H. Gruzelier. 2001. Electrophysiological evidence of serotonergic impairment in long-term MDMA ("ecstasy") users. Am J Psychiatry 158(10):1687-92
-
New Scientist website (Ecstasy and Parkinson’s) 11, November, 2006 ()
