やめたいけどやめられない―喫煙欲求と自己制御の神経機構

The Neural Mechanisms of Cigarette Craving and Self-control

喫煙欲求や薬物欲求は依存症の病態の本質で，薬物探索行動やその再発に重要な要因と考えられてきた。しかし行動経済学・心理学で欲求の研究が進むと，文脈や時間依存性の変化が大きいことが知られるようになった。脳機能画像法でも欲求関連脳活動の同定が進むにつれ文脈依存性の変動が明らかになった。これら文脈依存性は合理的意思決定論の導入により理論化され，前頭前野の機能的回路形成が自己制御と薬物欲求を担うこともわかってきた。

Abstract

A craving for cigarettes or drugs has been believed to be a fundamental psychopathological factor that drives drug-seeking behavior and relapse. Behavioral economics has revealed context-dependent changes in drug craving. Neuroimaging studies have also found craving-related signals that were altered depending on the context of the experiments. A rational decision-making theory modeled such context-dependency and uncovered a pivotal role of the prefrontal cortical circuit in both self-control and craving. Future studies should address how dopaminergic function and stress circuits can modify the function of decision-making circuits, and produce either craving or self-control.