Hippocrates wrote in 400 BC of a condition that today seems compatible with what we now know as attention deficit hyperactivity disorder (ADHD). He described patients who had ‘quickened responses to sensory experience, but also less tenaciousness because the soul moves on quickly to the next impression’, and he attributed this condition to an ‘overbalance of fire over water’. Hippocrates’ remedy for this situation was ‘barley rather than wheat bread, fish rather than meat, water drinks and many natural and diverse physical activities’.