Summary: Researchers report changes in brain chemistry in people who take the medication Ritalin without it being prescribed to them. Changes impacted body weight, risk taking behaviors and locomotive activity. Additionally, women were more sensitive to the behavioral effects that men.
Source: University at Buffalo.
New research from the University at Buffalo Research Institute on Addictions that explored the potential side effects of the stimulant drug Ritalin on those without ADHD showed changes in brain chemistry associated with risk-taking behavior, sleep disruption and other undesirable effects.
Ritalin, the brand name for methylphenidate, a central nervous system stimulant used in the treatment of attention deficit hyperactivity disorder, is a growing problem among college students who use it without a prescription as a so-called “study enhancer.” The drug works by increasing the concentration of certain neurotransmitters in the brain that control reasoning, problem solving and other behaviors.
“Although Ritalin’s effectiveness in treating ADHD is well-documented, few studies have looked at the drug’s effect on non-prescribed illicit use,” says Panayotis (Peter) Thanos, PhD, senior research scientist at RIA. “We wanted to explore the effects of this stimulant drug on the brain, behavior and development on non-ADHD subjects.”
Recent studies put college students’ nonprescription use of stimulant drugs (Ritalin and amphetamines such as Adderall and Dexedrine) at rates anywhere between 14 and 38 percent, depending on the type of college and age of student. The common belief is that these drugs can help students to focus and concentrate when studying and perform better on tests. Alarmingly, these drugs are finding their way into high schools, as well, for the same reasons.
Thanos’ team, which included many UB students he mentors, looked at changes in the brains of rats who received regular doses of methylphenidate during what would be equivalent to adolescence in humans, a time of significant brain growth and development.
“We saw changes in the brain chemistry in ways that are known to have an impact on the reward pathway, locomotor activity, and other behaviors, as well as effects on body weight,” Thanos says. “These changes in brain chemistry were associated with serious concerns such as risk-taking behaviors, disruptions in the sleep/wake cycle and problematic weight loss, as well as resulting in increased activity and anti-anxiety and antidepressive effects.”
Further research indicated that female subjects were more sensitive to the behavioral effects of methylphenidate than the males.
Thanos hopes that studying the effects of methylphenidate on those without ADHD may lead to a greater understanding of how the drug works on the brain and behavior, and can help researchers understand the impact of the drug on young people throughout development.
“Understanding more about the effects of methylphenidate is also important as people with ADHD show greater risk to be diagnosed with a drug dependency problem,” Thanos says. “In addition, this study highlights the potential long-range risks college students take in using Ritalin for a quick study boost.”
Funding: Thanos’ research was funded by the New York State Research Foundation and the National Institute of Child Health & Human Development (NICHHD) of the National Institutes of Health (NIH). His coauthors were David Komatsu, PhD, of Stony Brook University and Michael Hadjiargyrou, PhD, of the New York Institute of Technology.
Source: Cathy Wilde – University at Buffalo
Image Source: NeuroscienceNews.com image is in the public domain.
Original Research: Abstract for “Chronic oral methylphenidate treatment reversibly increases striatal dopamine transporter and dopamine type 1 receptor binding in rats” by Lisa S. Robison, Mala Ananth, Michael Hadjiargyrou, David E. Komatsu, and Panayotis K. Thanos in Journal of Neural Transmission. Published online January 23 2017 doi:10.1007/s00702-017-1680-4
Chronic oral methylphenidate treatment reversibly increases striatal dopamine transporter and dopamine type 1 receptor binding in rats
Previously, we created an 8-h limited-access dual bottle drinking paradigm to deliver methylphenidate (MP) to rats at two dosages that result in a pharmacokinetic profile similar to patients treated for attention deficit hyperactivity disorder. Chronic treatment resulted in altered behavior, with some effects persisting beyond treatment. In the current study, adolescent male Sprague–Dawley rats were split into three groups at four weeks of age: control (water), low-dose MP (LD), and high-dose MP (HD). Briefly, 4 mg/kg (low dose; LD) or 30 mg/kg (high dose; HD) MP was consumed during the first hour, and 10 mg/kg (LD) or 60 mg/kg (HD) MP during hours two through eight. Following three months of treatment, half of the rats in each group (n = 8–9/group) were euthanized, and remaining rats went through a 1-month abstinence period, then euthanized. In vitro receptor autoradiography was performed to quantify binding levels of dopamine transporter (DAT), dopamine type 1 (D1R)-like receptors, and dopamine type 2 (D2R)-like receptors using [3H] WIN35,428, [3H] SCH23390, and [3H] Spiperone, respectively. Immediately following treatment, HD MP-treated rats had increased DAT and D1R-like binding in several subregions of the basal ganglia, particularly more caudal portions of the caudate putamen, which correlated with some previously reported behavioral changes. There were no differences between treatment groups in any measure following abstinence. These findings suggest that chronic treatment with a clinically relevant high dose of MP results in reversible changes in dopamine neurochemistry, which may underlie some effects on behavior.
“Chronic oral methylphenidate treatment reversibly increases striatal dopamine transporter and dopamine type 1 receptor binding in rats” by Lisa S. Robison, Mala Ananth, Michael Hadjiargyrou, David E. Komatsu, and Panayotis K. Thanos in Journal of Neural Transmission. Published online January 23 2017 doi:10.1007/s00702-017-1680-4