New research from Drexel University College of Medicine finds young people who misuse or take illegal stimulants – known as "smart drugs" – risk long-term impairments to brain function. It is estimated that more than one million American students misuse smart drugs to increase their attention span, memory and capacity to stay awake, but investigators from Drexel's Department of Neurobiology & Anatomy, along with researchers from the University of Delaware, found that any short-term boost in mental performance due to smart drugs may come at a heavy cost: long-term decrease in brain plasticity, which is necessary for task switching, planning ahead and adaptive flexibility in behavior.
The National Institutes of Health–funded review is available in the open access journal Frontiers in Systems Neuroscience. Investigators examined three major pharmaceuticals under consideration as cognitive enhancers – methylphenidate, modafinil and the ampakines.
"These drugs have striking and deeply concerning effects on the juvenile prefrontal cortex function, a brain region that is primarily associated with learning, short-term memory, decision making, judgment and flexibility," says co-investigator Wen-Jun Gao, PhD, assistant professor, Department of Neurobiology & Anatomy at Drexel University College of Medicine. "It is clear from the current lack of research in the field that much work needs to be done in order to determine the safety of cognitive enhancers, particularly among healthy adolescents."
Risks for Young Brains
Methylphenidate is the most popular smart drug among kids today and often sold on the black market. It was originally developed as a prescription-only drug (sold as Ritalin and Concerta) to treat ADHD and works by increasing the level of neurotransmitter in the nervous system. Around 1.3 million American teenagers misused or abused methylphenidate without prescription in the previous month, according to The Partnership at Drugfree.org and the MetLife Foundation.
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.
Another popular smart drug is modafinil, sold under the name Provigil against narcolepsy and other sleep disorders. Believed to work by raising the levels of dopamine in between synapses of brain nerve cells, it can boost memory as well as the ability to work with numbers and do other mental tasks. But research indicates that modafinil could have similar long-term undesired effects as methylphenidate on the developing brain.
New Smart Drugs Pose Risks
Not yet widely used are ampakines, an emerging class of drugs currently studied by the United States military with the aim of increasing alertness in soldiers. Ampakines bind to so-called AMPA receptor molecules in the nervous system and boost the response of nerve cells and strengthening connections between them. Known to improve memory and cognition in rats and healthy human volunteers, ampakines are often considered to be relatively safe potential smart drugs. But they are not without dangers for young people: uncontrolled use of ampakines might over-excite the nervous system, damaging or killing nerve cells, caution the authors.
What Is Paramount?
"Understanding the behavioral and functional ramifications in the yet immature brains is paramount to mitigating risks for potential brain plasticity and consequent emotional and behavioral changes," adds Gao. "Cognitive enhancement is no longer a scientific fiction; we must consider the unique dynamics of the developing brain and proceed cautiously until thorough safety and efficacy parameters have been established."