The ventral striatum (VStr) integrates mesolimbic dopaminergic and corticolimbic glutamatergic afferents and forms an essential component of the neural circuitry regulating impulsive behaviour. This structure represents a primary target of psychostimulant medication, the first-choice treatment for attention-deficit/hyperactivity disorder (ADHD), and is biochemically modified by these drugs in animals. However, the effects of stimulants on the human VStr remain to be determined. We acquired anatomical brain MRI scans from 23 never-medicated adult patients with ADHD, 31 adult patients with a history of stimulant treatment and 32 control subjects, and VStr volumes were determined using individual rater-blinded region of interest delineation on high-resolution neuroanatomical scans. Furthermore, we also extracted VStr volumes before and after methylphenidate treatment in a subsample of the medication-naïve adult patients as well as in 20 never-medicated children with ADHD. We observed smaller VStr volumes in adult patients with a history of stimulant treatment in comparison to never-medicated patients. Moreover, our longitudinal analyses uncovered a reduction of grey matter volume in the bilateral VStr in adult patients after exposure to methylphenidate, which was followed by volumetric recovery to control level. In children, the same pattern of VStr volume changes was observed after treatment with methylphenidate. These findings suggest that the altered VStr volumes previously observed in patients with ADHD may represent a transitory effect of stimulant exposure rather than an intrinsic feature of the disorder. More generally, these data show that stimulant drugs can render plastic volume changes in human VStr neuroanatomy.

Methylphenidate (MPH) is the first choice of medical treatment for attention-deficit/hyperactivity disorder (ADHD). Its mechanism of action is to inhibit the reuptake of dopamine and noradrenaline mainly in the region of the striatum. It has been estimated that 10-30 % of patients with ADHD do not respond adequately to MPH. The aim of this study was to evaluate whether striatal differences exist between good and poor responders to MPH. The sample included 27 treatment-naïve children with ADHD between the ages of 6 and 14. MPH administration started 1 day after the MRI acquisition. After a month, psychiatrists established the good or poor response to treatment according to clinical criteria. MRI images were analyzed using a technique based on regions of interest applied specifically to the caudate and accumbens nuclei. Sixteen patients showed good response to MPH and 11 a poor one. Regions of interest analysis showed that good responders had a higher concentration of gray matter in the head of both caudate nuclei and the right nucleus accumbens. Furthermore, a significant correlation was found between caudate and accumbens nuclei volume and the Conners' Parent Rating Scale and Continuous Performance Test improvement. These results support the hypothesis of the involvement of the caudate and accumbens nuclei in MPH response and in ADHD pathophysiology.

The Theory of Mind Inventory is an informant measure designed to evaluate children's theory of mind competence. We describe the translation and cultural adaptation of the inventory by the following process: (1) translation from English to Spanish by two independent certified translators; (2) production of an agreed version by a multidisciplinary committee of experts; (3) back-translation to English of the agreed version by an independent translator; (4) discussion of the semantic, idiomatic, and cultural equivalence of the final version; (5) elaboration of the final test; (6) pilot test on 24 representatives of the autism spectrum disorders population and 24 representatives of typically developing children. The steps were conducted satisfactorily, producing the final version in Spanish, which showed good psychometric properties.

Resumen: El objetivo del estudio es investigar la utilidad de la escala obsesivo-compulsiva basada en el Child Behavior Checklist, OCS-CBCL (Nelson et al., 2001). Se determina la consistencia interna, la sensibilidad, la especificidad y el valor predictivo positivo y negativo para identificar el trastorno obsesivo-compulsivo (TOC) en tres muestras de niños y adolescentes (N = 26) apareadas por edad y género: (1) pacientes con TOC, (2) pacientes psiquiátricos sin TOC, (3) población general. El ANOVA muestra diferencias significativas entre grupos (p < 0,001) y el análisis pot-hoc de Scheffé diferencias significativas del grupo TOC con los otros dos grupos. La sensibilidad es del 73,1% al 76,9%, la especificidad del 78,8% al 86,5%, el VPP del 78,4% al 84,4% y el VPN del 76,3% al 77,3%. Los resultados sugieren la utilidad de la OCS-CBCL para la detección del TOC infanto-juvenil.Palabras clave: Adolescencia; CBCL; evaluación; infancia; ROC; trastorno obsesivo-compulsivo. Nelson's OCS-CBCL Subscale for the assessment of Obsessive-Compulsive Disorder (OCD) in children and adolescents: Validity analysis in a Spanish sampleAbstract: The aim of this study was to investigate the usefulness of the obsessive-compulsive scale based upon the Child Behavior Checklist, OCS-CBCL (Nelson et al., 2001). We determined internal consistency, sensitivity, specificity and positive and negative predictive value to identify obsessive-compulsive disorder (OCD) in three samples of children and adolescents (N = 26) matched for age and gender: (1) patients with OCD, (2) psychiatric patients without OCD, and (3) general population. The ANOVA revealed significant differences between groups (p < 0,001) and post-hoc Scheffé analysis showed significant differences between the OCD group and the other two. The sensitivity was 73.1% to 76.9%, specificity 78.8% to 86.5%, PPV 78.4% to 84.4% and NPV was 76.3% to 77,3%. The results suggest the usefulness of the OCS-CBCL for the detection of child and adolescent OCD.

Resumen: El tempo cognitivo lento (TCL) se ha asociado al trastorno de déficit de atención con hiperactividad subtipo inatento (TDAH-I). Se han encontrado síntomas TCL en grupos clínicos sin TDAH; correlaciones entre TCL y medidas de ansiedad y en otros trastornos psiquiátricos. Los resultados en las diferencias neuropsicológicas entre TCL y subtipos de TDAH son controvertidos. Algunos autores sugieren que altos niveles de TCL y TDAH podrían formar parte de un nuevo trastorno atencional. El objetivo de este artículo es realizar una revisión teórica de dicho constructo. Concluimos que queda demostrada la validez estadística del TCL, puede diferenciarse del TDAH y presenta unas características propias. Aunque TCL se asocie al TDAH-I, probablemente sea una entidad independiente a éste actuando como factor modulador de aspectos atencionales que inciden, no sólo en las funciones ejecutivas, sino también en ciertas manifestaciones psicopatológicas presentes sobre todo en la ansiedad o la depresión.Palabras clave: Tempo cognitivo lento (TCL); trastorno de déficit atención hiperactividad (TDAH); funciones ejecutivas; subtipos TDAH. Sluggish cognitive tempo: Review of a constructAbstract: Sluggish cognitive tempo (SCT) has been associated with attention deficit and hyperactivity disorder inattention subtype (ADHD-I). SCT symptoms have been found in clinical groups without ADHD, also correlations between SCT and measures of anxiety, and in other psychiatric disorders. The results regarding neuropsychological differences between subtypes of ADHD and SCT are controversial. Some authors suggest that high levels of both SCT and ADHD could be indicative of a new attentional disorder. The aim of this paper is a theoretical review of this construct. We conclude that there is a clear statistical validity of SCT; that it can be distinguished from ADHD and presents its own characteristics. Although SCT shows a strong association with ADHD, it probably is a separate entity that may act as a modulating factor of other attentional features that affect not only executive functions but also certain psychopathological manifestations mostly present in anxiety or depression.