Pediatric neuropsychology is a specialty area of psychology that uses knowledge of the developing brain in the evaluation, diagnosis, and management of children’s cognitive,behavioral, and emotional functioning. Example of pediatric disorders is Autism Spectrum Disorders (ASD), Attention-Deficit/Hyperactivity Disorder (ADHD), and schizophrenia (Kirkwood; 2003).ASD all share trouble with theory of mind, socialization, the pragmatics of language, and representational play. They may occur with or without additional verbal speech problems. ASD, comprising autism, Asperger’s syndrome, and pervasive developmental disorder (not otherwise specified), are highly genetic, neurodevelopmental conditions that are characterized by impaired communication, deficits in social reciprocity, and obsessional/repetitive behavior (Page; 2006), (Kutscher; 2005) ADHD is defined by persisting, developmentally inappropriate, cross-situational, impairing levels of inattention, impulsiveness, and hyperactivity (Russell; 2006).Schizophrenia is a psychotic disorder (or a group of disorders) marked by severely impaired thinking, emotions, and behaviors. Schizophrenic patients are typically unable to filter sensory stimuli and may have enhanced perceptions of sounds, colors, and other features of their environment. Most schizophrenics, if untreated, gradually withdraw from interactions with other people, and lose their ability to take care of personal needs and grooming (Weinberger and Laruelle;2002).Diagnosis of these disorders is difficult, because clinical symptoms overlap, and conventional structural neuro-imaging studies are vague, increased cerebral volume and substructures in childhood ASD. Previous studies in ADHD revealed that Magnetic Resonance Imaging (MRI) is normal. In schizophrenia, MRI demonstrated abnormalities providing evidence of a neurodegenerative process like the gliosis observed in the periventricular structure of the diencephalon, the periaqueductal region of the mesencephalon, and the basal forebrain; these studies have provided evidence of alterations of cerebral structures (Russell; 2006), (Margari; 2005).This opens the door for other imaging techniques as Proton magnetic resonance spectroscopy (1H-MRS) that is used to quantify a range of brain metabolites, including glutamine/glutamate (Glu+Gln); N-acetylaspartate (NAA), a marker of neuronal density and/or mitochondrial function; choline-containing compounds (Cho), a measure of membrane synthesis/turnover; creatine and phosphocreatine (Cr+PCr), a measure of cellular energy metabolism; and myo-inositol, a major osmolite and precursor to several brain metabolites. Advantages of MRS are being quantitative and allows multiple chemicals to be assayed simultaneously (Dager; 2003), (Page; 2006).Murphy et al. reported a significant increase in frontal (but not parietal) NAA, Cho, and Cr+PCr in adults with Asperger’s syndrome and ASD (Page; 2006), (Russell; 2006). In ADHD, 1H-MRS disclosed increased Cho/Cr ratio in basal ganglia, frontal, and parieto-occipital areas, and decreased NAA/Cr ratio in both basal ganglia and frontal areas (Margari; 2005).In schizophrenia research, MRS has been used to approach four general topics: (a) assays of brain chemicals, (b) evidence of tissue pathology, © functional analysis of specific neuronal populations, and (d) drug effects. NAA signals were reduced selectively and bilaterally in dorsolateral prefrontal, perihippocampal cortices, cingulated cortex, frontal and temporal lobes of many patients with schizophrenia (Weinberger and Laruelle; 2002).