INTRODUCTION: Methylphenidate is a widely-used drug for the treatment of attention deficit/hyperactivity disorder (ADHD) and other neuropsychiatric disorders. Sustained-attention deficits and poorer task performance in these disorders have been associated with default mode network (DMN) dysfunction in fMRI studies. DMN is a set of brain areas more activated during the resting-state. Under the execution of external tasks, there is an attenuation of DMN activity. In healthy individuals, DMN and task-positive network are anticorrelated. It has been suggested that methylphenidate could normalize the attenuated task-related DMN deactivation in attention- and inhibitory control-related disorders and that such normalization could improve task performance. PATIENTS AND METHODS: To explore the hypothesis of DMN deactivation after methylphenidate administration, we conducted a systematic review of the literature. RESULTS: After a systematic search, 12 studies were included in this review. For eligibility, studies were required to measure the effects of methylphenidate administration on the DMN activity. Eleven studies showed evidence of MPH-induced improvements in brain areas related to DMN. The results suggest a normalization of brain circuits in individuals with DMN dysfunction. CONCLUSIONS: Our preliminary findings strongly suggest methylphenidate improves DMN dysfunction presented in ADHD and other neuropsychiatric disorders. Further studies are needed to better understand this effect and expand comprehension of methylphenidate action mechanisms.
INTRODUCTION:Methylphenidate is a widely-used drug for the treatment of attention deficit/hyperactivity disorder (ADHD) and other neuropsychiatric disorders. Sustained-attention deficits and poorer task performance in these disorders have been associated with default mode network (DMN) dysfunction in fMRI studies. DMN is a set of brain areas more activated during the resting-state. Under the execution of external tasks, there is an attenuation of DMN activity. In healthy individuals, DMN and task-positive network are anticorrelated. It has been suggested that methylphenidate could normalize the attenuated task-related DMN deactivation in attention- and inhibitory control-related disorders and that such normalization could improve task performance. PATIENTS AND METHODS: To explore the hypothesis of DMN deactivation after methylphenidate administration, we conducted a systematic review of the literature. RESULTS: After a systematic search, 12 studies were included in this review. For eligibility, studies were required to measure the effects of methylphenidate administration on the DMN activity. Eleven studies showed evidence of MPH-induced improvements in brain areas related to DMN. The results suggest a normalization of brain circuits in individuals with DMN dysfunction. CONCLUSIONS: Our preliminary findings strongly suggest methylphenidate improves DMN dysfunction presented in ADHD and other neuropsychiatric disorders. Further studies are needed to better understand this effect and expand comprehension of methylphenidate action mechanisms.