Between 2 and 5% of the global population have ADHD. Left untreated, it is linked to functional impairments, increased risk of mood and anxiety disorders, and other consequences, including a higher suicide risk. The primary treatment for ADHD involves stimulant medications such as methylphenidate and d-amphetamines, which carry side effects like appetite loss, hypertension, headache, sleep disturbances, and a high risk of abuse.
Second-line options also carry negative side effects while being less effective than stimulants, and around 25% of patients experience no significant improvement from any drug. New options for treating ADHD are thus in urgent need.
In the current study, researchers tested five drugs with the potential for being repurposed for ADHD in rat models of the condition. Ultimately, just one of the drugs, amlodipine, reduced hyperactivity in the rats. In further tests in zebrafish, the drug reduced both hyperactivity and impulsivity.
Amlodipine was able to cross the blood-brain barrier. Analysis of human genetic data revealed that ADHD is linked to the same calcium channels in the brain as the targets for amlodipine. Meanwhile, an analysis of UK-wide patient data also conducted by the researchers found that people who take amlodipine had fewer mood swings and less risk-taking behavior.
"Repurposing amlodipine, a well-established blood pressure medication, offers a promising and swift pathway to address ADHD symptoms. Our research indicates that, due to its existing approval and safety profile, amlodipine could be rapidly redeployed as a treatment option for ADHD, potentially providing relief to patients sooner than developing new medications,” said co-author of the study, Dr. Matthew Parker, Associate Professor of Neuroscience and Behavioural Analysis at the University of Surrey, in a press release.
Sources: Science Daily, Neuropsychopharmacology
