The complexities of treating conditions like ADHD and depression during adolescence require a delicate balance. These conditions often overlap and are commonly managed with a combination of medications such as Ritalin, known for its usefulness in ADHD treatment, and fluoxetine, an antidepressant. Both medications have their merits but also come with risks, especially when misused by teenagers looking for a cognitive boost or for recreational purposes. Surprisingly, a significant number of high schoolers have been found to experiment with these prescription drugs outside their medical intent, spotlighting a potential gateway to substance misuse. This study probes deeper into the implications of combining these drugs during one’s teenage years, questioning whether such early exposure might unwittingly pave the way to increased susceptibility to cocaine addiction later on.

In detailed research led by Professor Panayotis Thanos from the University at Buffalo and Professor Heinz Steiner from Rosalind Franklin University, with support from Dr. David Komatsu from Stony Brook University, Professor Michael Hadjiargyrou from New York Institute of Technology, and Wen Lee, Shannon Klein, Rania Ahmed, Madison McCarthy and Daniela Senior from the University at Buffalo, a troubling link has been discovered. Published in Addiction Neuroscience, the research examines the long-term effects of concurrently prescribing Ritalin and fluoxetine during adolescence, revealing a noticeable uptick in cocaine use in adolescent rats. This crucial research brings to light the potential dangers of co-prescribing these medications during the teenage years, indicating a possible increase in the likelihood of future substance abuse issues.

Professor Thanos, Professor Steiner and their research team conducted their investigation by dividing adolescent male rats into four distinct groups, which received different treatments through their drinking water for a month. One group had plain water, serving as a baseline for comparison, while the others were treated with either Ritalin, fluoxetine, or a combination of both. After this month-long treatment phase, the animals were tested on their propensity to self-administer cocaine over two weeks, offering insights into their potential drug-seeking behavior following treatment.

Professor Thanos shares, “We found that in the first week of self-administering cocaine, rats previously treated with Ritalin exhibited a notable increase in their activity to obtain cocaine, significantly more than those who had water. By the second week, rats that had been treated with both Ritalin and fluoxetine showed an even more marked inclination towards cocaine, displaying a significantly higher level of activity and increased cocaine consumption compared to the control group.” This underlines the significant impact these medications can have when used together.

To accurately administer cocaine for the self-administration tests, each rat was surgically prepared with a catheter connected to their jugular vein. The experimental setup included two levers in the operant chambers: one that would deliver cocaine upon pressing and another that remained inactive, serving as a control to differentiate drug-seeking behavior from general activity levels.

Professor Steiner, discussing the results, remarked, “Our findings that chronic treatment with a mix of Ritalin and fluoxetine during adolescence leads to increased cocaine use later on is groundbreaking. It suggests that taking these two drugs together for an extended period during the teenage years could make individuals more susceptible to cocaine addiction as young adults.” This important insight necessitates a reassessment of how these medications are prescribed to young individuals, particularly those undergoing treatment for ADHD and depression.

The research’s approach opens new paths for understanding how early-life exposure to certain medications can influence drug consumption patterns later in life. “We aimed to see whether the same treatment regimen that led to changes in behavior would also affect how much cocaine the rats would use,” Professor Thanos further clarifies, illuminating the methodology behind their significant discovery. This investigation not only highlights the risks associated with the simultaneous use of Ritalin and antidepressants such as fluoxetine but also lays the groundwork for future research into the enduring effects of psychiatric medication on the likelihood of substance abuse. As we move forward, Professor Panayotis Thanos and Professor Heinz Steiner emphasize the importance for both the scientific community and healthcare providers to heed these findings, ensuring that treatment strategies for adolescents are carefully vetted to avoid potential risks of drug addiction.


Daniela Senior, Panayotis K. Thanos et al., “Chronic oral methylphenidate plus fluoxetine treatment in adolescent rats increases cocaine self-administration,” Addiction Neuroscience, 2023.



Dr. Panayotis Thanos

Dr. Panayotis (Peter) Thanos is a Senior Research Scientist and Research Professor, as well as the Director of the Behavioral Neuropharmacology and Neuroimaging Laboratory on Addictions (BNNLA) at the Clinical Research Institute on Addictions, in the Department of Pharmacology and Toxicology at the Jacobs School of Medicine and Biomedical Sciences, University at Buffalo. Dr. Thanos has been awarded various research and mentoring awards including the US Department of Energy Outstanding Mentor Award. Dr. Thanos has authored/coauthored over 220 peer-reviewed journal articles and has an H-index of 55.  Dr. Thanos’ research is focused on Behavioral Neuropharmacology and Neuroimaging of Addiction and Substance Abuse. His research is based on the concept that there are specific genetic and epigenetic vulnerabilities that significantly contribute to Reward Deficiency Syndrome (RDS) of which addiction is a part of.  Dr. Thanos’ lab utilizes molecular, behavioral, and imaging (Positron Emission Tomography, MRI, CT, Autoradiography) methods in animal models, and investigates how these models contribute to clinical data as part of several ongoing clinical translational studies.

Dr. Heinz Steiner

Dr. Heinz Steiner is a Full Professor of Cellular and Molecular Pharmacology at the Chicago Medical School, Rosalind Franklin University of Medicine and Science, and a Principal Investigator in the Stanson Toshok Center for Brain Function and Repair at Rosalind Franklin University. Dr. Steiner received his M.S. in Biology from the Swiss Federal Institute of Technology (ETH) in Zurich, Switzerland, and his Ph.D. in Physiological Psychology from the University of Dusseldorf, Germany. After post-doctoral work at the National Institute of Mental Health, Bethesda, he was a Research Assistant Professor in the Department of Anatomy and Neurobiology at the University of Tennessee, College of Medicine and The Center for Neuroscience in Memphis. He joined the faculty in the Department of Cellular and Molecular Pharmacology at the Chicago Medical School in 2000, and was department chair from 2011-2022. Dr. Steiner’s research focuses on the functional organization of the basal ganglia and related brain systems, especially on the role of the neurotransmitters dopamine and serotonin in the regulation of basal ganglia – cortical interactions. One of the main objectives of his work is to understand how treatments with dopaminergic and serotonergic drugs produce changes in gene regulation in the basal ganglia and their consequences for drug addiction and other brain disorders. Dr. Steiner is the senior editor of the “Handbook of Basal Ganglia Structure and Function” and a co-editor of Elsevier’s “Handbook of Behavioral Neuroscience” series.