Association between microstructural integrity of frontostriatal tracts and school functioning: ADHD symptoms and...

Area of Science:

• Neuroscience
• Child Psychology
• Developmental Disorders

Background:

• Attention-deficit/hyperactivity disorder (ADHD) is associated with executive function (EF) deficits, impaired school functioning, and altered white matter integrity in frontostriatal networks.
• The precise relationships between these impairments in ADHD remain unclear.

Purpose of the Study:

• To examine the association between the microstructural integrity of frontostriatal tracts and school dysfunction in youths.
• To investigate the mediating roles of executive function (EF) and ADHD symptoms in this association.

Main Methods:

• A sample of 32 Taiwanese youths with ADHD and 32 typically developing (TD) controls were assessed.
• Psychiatric interviews, parent reports on ADHD symptoms and school functioning, and EF measures (CANTAB) were utilized.
• Frontostriatal tracts were reconstructed using diffusion spectrum imaging (DSI) tractography and segmented into four distinct tracts.

Main Results:

• Youths with ADHD exhibited altered white matter integrity (decreased general fractional anisotropy) in all four bilateral frontostriatal tracts compared to TD youths.
• ADHD group showed deficits in attention, vigilance, and response inhibition, alongside impaired school functioning.
• Altered frontostriatal tract integrity was significantly associated with school dysfunction, mediated by EF (attention/vigilance, response inhibition) and ADHD symptoms (inattention, hyperactivity).

Conclusions:

• White matter integrity in frontostriatal networks is associated with school functioning in youths.
• Executive function deficits and ADHD symptoms appear to be mediating mechanisms linking white matter integrity to school dysfunction.
• Further research is required to establish the directionality and specificity of these findings.