Spectroscopic findings in attention-deficit/hyperactivity disorder: review and meta-analysis.
OBJECTIVE
The last decade has seen an increasing interest in the method of magnet resonance spectroscopy (MRS) since this is the only research tool that allows a non-invasive in vivo assessment of neurochemical aspects of ADHD without employing ionising radiation. In this paper we review published MRS results with respect to childhood, adolescence and adult ADHD.


METHODS
We searched the Medline (Pub Med) database using the key words ADHD, attention-deficit/hyperactivity disorder, magnet resonance spectroscopy, MRS and spectroscopy. Citations of identified articles were also searched for relevant studies. Meta-analyses were performed for the measured metabolites and regions of assessment.


RESULTS
Sixteen studies could be identified that used MRS to investigate the neurobiology of ADHD. Two regions could be identified as the focus of spectroscopic investigations--the frontal lobe including anterior cingulate cortex and parts of prefrontal cortex and the basal ganglia, mostly striatum, alongside the fronto-striato-thalamo-frontal circuits. As for metabolites, in the majority of studies the ratios to creatine and not absolute concentrations of metabolites were estimated. Choline compounds, N-acetyl-aspartate and glutamate/glutamine (to creatine ratios) could be identified as being altered in several studies in ADHD. The meta-analysis showed increased choline compounds in several researched regions.


CONCLUSIONS
MRS is a promising tool for the non-invasive in vivo assessment of the cerebral neurochemistry in ADHD. More regions of interest (ROI) like amygdala, hippocampus, thalamus and cerebellum should be assessed in future studies. Further methodological improvements of MRS are desirable in order to assess the absolute metabolite concentration of several ROIs at the same time. Such developments will open novel perspectives in spectroscopic investigations of ADHD.
Perlov
Evgeniy
E
Department of Psychiatry and Psychotherapy, University Hospital Freiburg, Freiburg, Germany. evgeniy_perlov@psyallg.ukl.uni-freiburg.de
Philipsen
Alexandra
A
Matthies
Swantje
S
Drieling
Tobias
T
Maier
Simon
S
Bubl
Emanuel
E
Hesslinger
Bernd
B
Buechert
Martin
M
Henning
Jurgen
J
Ebert
Dieter
D
Tebartz Van Elst
Ludger
L
D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D001921:Brain / Q000503:physiopathology*; D002648:Child; D004292:Dominance, Cerebral / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008563:Membrane Lipids / Q000378:metabolism*; D018377:Neurotransmitter Agents / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism*; D012016:Reference Values
D008563:Membrane Lipids; D018377:Neurotransmitter Agents; D010710:Phosphates