Ventro-striatal reductions underpin symptoms of hyperactivity and impulsivity in attention-deficit/hyperactivity disorder.
BACKGROUND
Models of attention-deficit/hyperactivity disorder (ADHD) classically emphasize the relevance of executive processes and, recently, reward circuits. The neural bases of reward processes have barely been explored in relation to this disorder, in contrast to extensive neuroimaging studies that examine executive functions in patients with ADHD. To our knowledge, no previous studies have analyzed the volume of the ventral striatum, a key region for reward processes in ADHD children.


METHODS
We used a manual region-of-interest approach to examine whether there were volumetric differences in the ventral striatum of ADHD children. Forty-two children/adolescents with ADHD (ages 6-18), and 42 healthy control subjects matched on age, gender, and handedness were selected for the study.


RESULTS
The ADHD children presented significant reductions in both right and left ventro-striatal volumes (t = 3.290, p = .001; and t = 3.486, p = .001, respectively). In addition, we found that the volume of the right ventral striatum negatively correlated with maternal ratings of hyperactivity/impulsivity (r = -.503, p = .003).


CONCLUSIONS
Our study provides neuroanatomical evidence of alterations in the ventral striatum of ADHD children. These findings coincide with previous explicative models as well as with recent reports in behavioral and functional neuroimaging studies. Furthermore, the negative correlations we observed strongly uphold the relation between the ventral striatum and symptoms of hyperactivity/impulsivity.
Carmona
Susanna
S
Unitat de Recerca en Neurociència Cognitiva, Departament de Psiquiatria i Medicina Legal, Universitat Autònoma de Barcelona, Bellaterra, Spain. susannacarmona@gmail.com
Proal
Erika
E
Hoekzema
Elseline A
EA
Gispert
Juan-Domingo
JD
Picado
Marisol
M
Moreno
Irene
I
Soliva
Juan Carlos
JC
Bielsa
Anna
A
Rovira
Mariana
M
Hilferty
Joseph
J
Bulbena
Antonio
A
Casas
Miquel
M
Tobeña
Adolf
A
Vilarroya
Oscar
O
D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications* / Q000473:pathology; D001479:Basal Ganglia / Q000473:pathology*; D001931:Brain Mapping; D016022:Case-Control Studies; D002648:Child; D005260:Female; D007839:Functional Laterality; D006801:Humans; D006948:Hyperkinesis / Q000209:etiology* / Q000473:pathology*; D007091:Image Processing, Computer-Assisted; D007175:Impulsive Behavior / Q000209:etiology* / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009483:Neuropsychological Tests; D013223:Statistics as Topic