Attention-deficit Disorder Subtypes Research Articles

Hypokalemic Sensory Overstimulation

This report describes 2 generations of a family with symptoms of sensory overstimulation that exhibit a potassium sensitivity similar to that seen in hypokalemic periodic paralysis. The sensory overstimulation is characterized by a subjective experience of sensory overload and a relative resistance to lidocaine local anesthesia. The sensory overload is treatable with oral potassium gluconate, with onset of the therapeutic effect in approximately 20 minutes. The effect of potassium is reminiscent of its effect in the channelopathies underlying hypokalemic periodic paralysis, and the resistance to lidocaine applied peripherally suggests a peripheral sensory localization to the abnormality. The phenotype overlaps with that of attention deficit disorder, raising the possibility of subtypes of attention deficit disorder that have a peripheral sensory cause and novel forms of therapy.

Behavioral Subtypes of Attention Deficit Disorder

This article reviews research on three behavioral subtypes of attention deficit disorder (ADD): without hyperactivity (ADD/WO), with hyperactivity (ADDH), and with hyperactivity and aggression (ADDHA). Children with ADDHA appear to be at increased risk to have oppositional and conduct disorders, whereas children with ADD/WO tend to show symptoms such as anxiety and depressed mood. Children in the three subtypes have similar rates of learning disabilities, but all have higher rates than found in control groups. Teacher and parent ratings are more sensitive than laboratory measures in differentiating the subtypes. Follow-up studies strongly suggest more adverse outcomes for ADDHA children.

Anxiety and depressive disorders in attention deficit disorder with hyperactivity: new findings.

The authors examined the discriminant validity of the diagnosis of attention deficit disorder with hyperactivity. They used standardized rating scales of life stresses and child and family functioning to assess psychosocial and family risk factors in 47 children who had the diagnosis of attention deficit disorder with hyperactivity, a matched group of 47 children in the community, and a matched group of 47 children seen in a psychiatric clinic. Children who had the diagnosis of attention deficit disorder and children in the psychiatric clinic reported significantly more depression and anxiety than did the children in the community; furthermore, children diagnosed as having attention deficit disorder with hyperactivity had more externalizing symptoms than did children in the psychiatric clinic. Children diagnosed as having attention deficit disorder with hyperactivity plus a comorbid anxiety or depressive disorder had higher levels of coexisting life stresses and parental symptoms than did children who had the single diagnosis of attention deficit disorder with hyperactivity. These results underscore the need for future studies to carefully assess children diagnosed as having attention deficit disorder with hyperactivity for concurrent psychiatric disorders as well as family and psychosocial stressors that may contribute to childhood symptoms. Such information is essential because different subtypes of attention deficit disorder with comorbid disorders may arise from different etiologic pathways, may require varying treatment options, and may foreshadow different eventual outcomes.

Attentional control systems and the Attention Deficit Disorders (ADD)

This article focuses on neuropsychological hypotheses regarding self-regulation, with a special emphasis on those which would provide for the behaviorally differentiated subtypes of Attention Deficit Disorder (ADD) with and without hyperactivity. Specifically, this article (1) reviews the history and current status of the diagnostic category of ADD, particularly with regard to this Subtyping distinction, (2) discusses various neurological structures and biochemical systems believed involved in the regulation of attention and impulse control, (3) presents an integrative neuropsychological model of attention control which would allow for these subtypes of ADD, and (4) relates this model to clinical findings in children and adolescents with these disorders. It is concluded that the literature in this area of childhood psychopathology is consistent with the notion that these subtypes of ADD exist and that they may well be related to associated deficiencies in neurotransmitter systems involving dopamine and norepinephrine. Further, there may be interactions involving these subtypes and lateralized and anterior-posterior regulatory-attentional systems.