Decreased caudate N-acetyl-l-aspartic acid in pediatric obsessive-compulsive disorder and the effects of behavior therapy

The current study used magnetic resonance spectroscopy (MRS) to investigate differences in absolute levels of neurochemicals in the head of the caudate nucleus (HOC) and anterior cingulate cortex (ACC) between 15 children with obsessive-compulsive disorder (OCD) and a matched control group, as well as the effects of behavior therapy on these chemicals. At baseline, absolute levels of N-acetyl-l-aspartate (NAA) in the left HOC were significantly lower in non-medicated patients (N = 8) with OCD compared to medicated patients (N = 5) and compared to matched controls (N = 9). Exploratory analyses provided preliminary data suggesting that behavior therapy is associated with a decrease in Glx (glutamate+glutamine) in the right HOC (N = 7). The baseline differences in NAA replicate previous finding from the adult literature and show a relationship between NAA in OCD across the lifespan. The changes in Glx raise the possibility that behavior therapy and medication treat OCD symptoms through similar pathways.