注意欠陥多動性障害（ADHD）および 破壊的行動障害における衝動性－その症状はドーパミン系、それともセロトニン系の制御不全のいずれによるのか－

Abstract

Attention-deficit hyperactivity disorder ( ADHD) is characterized by pervasive and impairing symptoms of inattention, hyperactivity, and impulsivity, being one of the most common neuropsychiatric disorders with childhood onset. Since the latter part of 1990’s, it has been hypothesized that ADHD symptoms are caused by neuropsychological dysfunction, namely executive dysfunction, specifically behavioral dysinhibition. Dopaminergic dysregulation in dorsolateral prefrontal cortex (DLPFC) is thought to be involved in these dysfunctions. But recent studies indicate ADHD symptoms may also occur from serotonergic dysregulation. In this case, oppositional defiant disorder (ODD) and conduct disorder (CD) are highly comorbid with ADHD, and SSRI can have more effect on the symptoms than metylphenidate hydrochlorine (MPH) or amphetamine. In the present review, the author looked into extant evidences with regard to “impulsivity” as multifaceted construct, and concluded that, while pure ADHD may be caused by behavioral dysinhibition ( impulsivity without emotional urgency), ADHD with ODD or CD may be caused by impulsivity with emotional urgency.