19 - Norepinephrine in attention-deficit/hyperactivity disorder

Summary

Introduction

Among the psychiatric disorders that involve norepinephrine (NE), attention-deficit/hyperactivity disorder (ADHD) is one of the most widespread and clinically significant. There is general agreement that neurological and genetic factors related to central nervous system NE and dopamine (DA) function are primary in its etiology. There have been multiple studies, some controlled and positive, of NE agents in the treatment of ADHD. However, the success of these studies has not diminished the wide popularity of the dual-acting stimulants, methylphenidate and dextroamphetamine, as first-line agents for the treatment of ADHD. Except for special populations or as second-line agents, many clinicians use NE agents infrequently. Many believe that NE's clinical effects are distinctly less robust than those of stimulants. The success of atomoxetine has produced questions about this belief and raised important theoretical concerns regarding the role for NE in ADHD. There is still controversy regarding its efficacy versus that of stimulants, and the relative efficacy of atomoxetine versus stimulants has not been carefully tested.

Historical overview

While there are earlier literary references to maladies similar to ADHD, the first description in the medical literature is attributed to Sir George Still in a 1902 publication. Still described 20 children using adjectives such as aggressive, passionate, lawless, inattentive, impulsive, and overactive. Several of his most important observations regarding the disorder have been corroborated over the following decades.