Differences between attention-deficit disorder with and without hyperactivity: a 1H-magnetic resonance spectroscopy...

Area of Science:

• Neuroscience
• Biochemistry
• Medical Imaging

Background:

• Attention-deficit/hyperactivity disorder (ADHD) presents with heterogeneous subtypes, including predominantly inattentive (ADHD-I) and combined (ADHD-C).
• Neurometabolic differences may underlie subtype variations in ADHD.
• Proton magnetic resonance spectroscopy ((1)H-MRS) is a non-invasive tool for assessing brain metabolites.

Purpose of the Study:

• To investigate neurometabolic differences in the lenticular nucleus between ADHD-I, ADHD-C, and normal controls using (1)H-MRS.
• To identify specific metabolite alterations associated with ADHD subtypes.

Main Methods:

• Proton magnetic resonance spectroscopy ((1)H-MRS) was performed on the lenticular nucleus of schoolboys diagnosed with ADHD (n=20) and matched controls (n=10).
• ADHD participants were classified into ADHD-I (n=10) and ADHD-C (n=10) subtypes based on DSM-IV criteria.
• Key metabolites including N-acetylaspartate (NAA), Choline (Cho), myo-inositol (mI), and creatine (Cr) were quantified, and their ratios to Cr were calculated.

Main Results:

• Significant overall group differences in the NAA/Cr ratio were observed in both the right and left lenticular nucleus.
• The ADHD-C subtype exhibited significantly lower NAA/Cr ratios compared to normal controls in both the right and left lenticular nucleus.
• The ADHD-C group showed significantly lower NAA/Cr ratios than the ADHD-I group in the right lenticular nucleus, with a similar trend in the left.

Conclusions:

• This study demonstrates measurable neurometabolic differences between ADHD-C and ADHD-I subtypes using (1)H-MRS.
• Alterations in N-acetylaspartate levels within the lenticular nucleus may serve as a biomarker distinguishing ADHD subtypes.