Studies Showing Long-term brain damage from ADHD Drugs

The below is the science-based evidence why I have come to believe that short-term cognitive enhancers are long-term cognitive weakeners, and that ADHD drugs destroy lives in the long-run if children stay on them long enough. A 14 year long study has analyzed the data from thousands of Canadian children who were put on Ritalin. This is the longest and the largest randomized study ever done on the long-term effects of stimulant use in children (http://chs.ph.ucla.edu/do-stimulant-medications-improve-educational-and-behavioral-outcomes-children-adhd) The abstract states: "We find evidence of increases in emotional problems among girls, and reductions in educational attainment among boys." The body of the paper states: "We find no evidence that the performance of children with ADHD improved. In fact, the increase in medication use among children with ADHD is associated with increases in the probability of grade repetition, lower math scores, and a deterioration in relationships with parents [these results are called “medium-term” in the paper and refer to outcomes measured biannually every six months]. When we turn to an examination of long-term outcomes, we find that increases in medication use are associated with increases in the probability that a child has ever suffered from depression and decreases in the probability of post secondary education among girls." Below are the studies seeming to explain why such worse school performance was observed in the thousands of children on Ritalin in Canada in the long-run. These studies show that long-term stimulant exposure can cause the weakening of cognition, learning ability and memory due to inducing diminished ‘brain plasticity.’ The meaning of ‘brain plasticity’ (also called synaptic plasticity or neural plasticity) and its role in our learning ability is explained by Dr. Pascale Michelon, PhD:[http://sharpbrains.com/blog/2008/02/26/brain-plasticity-how-learning-changes-your-brain/] "For a long time, it was believed that as we aged, the connections in the brain became fixed. Research has shown that in fact the brain never stops changing through learning. Plasticity IS the capacity of the brain to change with learning. Changes associated with learning occur mostly at the level of the connections between neurons. New connections can form and the internal structure of the existing synapses can change." In other words, the brain’s plasticity refers to the way its neural structure can change on demand as a result of learning new skills. But in 2014, a systematic review published in Frontiers in Systems Neuroscience,[https://dx.doi.org/10.3389%2Ffnsys.2014.00038] determined that short-term performance enhancement in stimulant users comes “at the potential cost of brain plasticity that is associated with the neural ramifications of nootropic drugs [cognitive enhancers] in the healthy developing brain.” Healthline covered this study in their article titled “Popular Study Drugs Pose Special Risks for Young Brains,” reporting that “the lasting side effects of taking these drugs include impairments in working memory, multitasking ability, and attentional flexibility.”[http://www.healthline.com/health-news/study-drugs-have-long-term-consequences-for-young-minds-051414] These are “skills that become very important in the workforce and managing the many demands and stressors of modern adult life,” according to study author Kimberly Urban, Ph.D.[http://www.healthline.com/health-news/study-drugs-have-long-term-consequences-for-young-minds-051414] Not only Healthline but other popular online medical information sources also reported the findings of the 2014 review published in Frontiers in Systems Neuroscience. These sources include LiveScience,[http://www.livescience.com/45621-students-risk-brain-problems-from-smart-drugs.html] which announced that “Students Risk Brain Problems from ‘Smart’ Drugs.” Time magazine which covered the same study announced that “smart drugs used to boost performance in the short term have long term damage for the young brain, a new study says.”[http://time.com/97448/bad-news-for-ivy-leaguers-adhd-drugs-hurt-your-memory/] MedicalDaily announced this finding in an article titled “Stimulants Used Among Young Adults Linked To Permanent Brain Impairment: A Call To Put Down The Smart Drugs.”[http://www.medicaldaily.com/stimulants-used-among-young-adults-linked-permanent-brain-impairment-call-put-down-smart-drugs] ScienceDaily also summarized:[https://www.sciencedaily.com/releases/2014/05/140513113453.htm] "Trials on rats have shown that young, developing brains are particularly sensitive to methylphenidate: even low dosages early in life can reduce nerve activity, working memory, and the ability to quickly switch between tasks and behaviors. Such mental flexibility is important for complex motoric learning, interpersonal skills, and work performance." In the article in ScienceDaily,[https://www.sciencedaily.com/releases/2014/05/140513113453.htm] ampakines are described as “an emerging class of drugs currently studied by the US military with the aim of increasing alertness in soldiers.” ScienceDaily then points out that according to the authors of the 2014 systematic review published in Frontiers in Systems Neuroscience, although ampkines have been promoted as being relatively safer than stimulants, they too may “over-excite the nervous system, damaging or killing nerve cells.” ScienceDaily also reports about the “smart” drug called modafinil that “research indicates that modafinil could have similar long-term undesired effects as methylphenidate on the developing brain.” The debilitating effects of the long-term use of stimulants on cognition and learning ability have been confirmed by other studies such as an August 2003 paper titled “Amphetamine or Cocaine Limits the Ability of Later Experience to Promote Structural Plasticity in the Neocortex and Nucleus Accumbens”, published in Proceedings of the National Academy of Sciences of the United States of America.[http://www.pnas.org/content/100/18/10523.full] The structures in our brains which are responsible for the brain’s plasticity (ability to change through learning) are called dendritic spines.[http://www.nature.com/nrn/journal/v2/n12/full/nrn1201-880a.html] “Spine dynamics are cellular phenomena with important implications for cognition and memory,” explains an article published in March 2010 in Trends in Neurosciences.[https://dx.doi.org/10.1016/j.tins.2010.01.001] The chronic use of stimulants pathologically increase the density of dendritic spines and increase dendrite branching in various brain regions.[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2650365/] [http://www.ncbi.nlm.nih.gov/pubmed/10215912] In a 1999 article published in the European Journal of Neuroscience titled “Alterations in the morphology of dendrites and dendritic spines in the nucleus accumbens and prefrontal cortex following repeated treatment with amphetamine or cocaine,” the researchers explain:[http://www.ncbi.nlm.nih.gov/pubmed/10215912] "Repeated treatment with psychostimulant drugs produces changes in brain and behaviour that far outlast their initial neuropharmacological actions. The nature of persistent drug-induced neurobehavioural adaptations is of interest because they are thought to contribute to the development of dependence and addiction, and other forms of psychopathology, e.g. amphetamine psychosis." The researchers of this study had reached this same conclusion also in an earlier 1997 study.[http://www.jneurosci.org/content/17/21/8491.long] The previously mentioned March 2010 paper published in Trends in Neurosciences[https://dx.doi.org/10.1016/j.tins.2010.01.001 ] also confirms that “impaired [dendritic] spine dynamics can cause psychiatric and neurodevelopmental disorders.” This explains the 11 amphetamine induced psychiatric disorders listed in the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) of the American Psychiatric Association.[http://emedicine.medscape.com/article/289973-overview]