Dorsal/ventral parcellation of the amygdala: relevance to impulsivity and aggression.

Investigations into the specific association of amygdala volume, a critical aspect of the fronto-limbic emotional circuitry, and aggression have produced results broadly consistent with the 'larger is more powerful' doctrine. However, recent reports suggest that the ventral and dorsal aspects of the amygdala play functionally specific roles, respectively, in the activation and control of behavior. Therefore, parceling amygdala volume into dorsal and ventral components might prove productive in testing hypotheses regarding volumetric association to aggression, and impulsivity, a related aspect of self-control. We sought to test this hypothesis in a group of 41 psychiatric patients who received standard magnetic resonance imaging and a psychometric protocol including aggression and impulsivity measures. Whole amygdala volumes were not associated with aggression or impulsivity, but significant correlations were found when dorsal/ventral amygdalae were analyzed separately. Specifically, left and right ventral amygdala volume was positively associated with motor impulsivity, and left dorsal amygdala was negatively associated with aggression. Results are discussed in terms of an activation and control model of brain-behavior relations. Potential relevance to the continuum of amygdala hyper- to hypo-activation and aggression is discussed.

The impact of neuropsychological functioning on treatment outcome in pediatric obsessive-compulsive disorder.

BACKGROUND: Scant research has examined the effect of neuropsychological (NP) functioning on treatment outcome in pediatric obsessive-compulsive disorder (OCD). This study sought to address this gap in existing research. METHODS: A total of 63 youths were included in this study and asked to complete the Rey-Osterrieth Complex Figure (ROCF) and specific subtests of the Wechsler Intelligence Scale for Children, Third Edition (WISC-III). RESULTS: Analyses suggest that 5 min recall accuracy (raw score) and percent recall from the ROCF, assessed before treatment may be predictors of treatment response among children with OCD. What is more, exploratory post hoc analyses indicated that performance on these ROCF tasks is particularly relevant among youths receiving cognitive-behavior therapy (CBT) alone. These results may be driven by executive functioning ability. Additional analyses suggest a relationship between age, symptom severity, and NP functioning on select tasks from both the ROCF and WISC-III. CONCLUSIONS: Although alternative explanations exist, these findings suggest that poorer performance on the ROCF and, in turn, poorer response to treatment, particularly among those youths receiving CBT alone, may be due to executive functioning difficulties. Clinicians and researchers should be sensitive to this fact and may warrant modification(s) to existing treatment protocols. Limitations to this study, however, suggest the need for replication and extension of these findings in the future.