Psychophysiology of child psychopathology

Galvanic Skin Response (GSR), a standardized method of measuring autonomic nervous system (ANS) arousal, was studied in 42 children (age 5-12 years) hospitalized for affective (depression and dysthymia) or behavior disorders (conduct, oppositional defiant and attention deficit) and 23 controls. GSR was measured for both left and right hands.^ Two habituation sessions (one at 70 dB, one at 90 dB) and a reaction time (skin response only was recorded) session were presented. Each child also completed subjective ratings of depression and anxiety.^ The results suggest that psychiatrically hospitalized children do indeed have differences in their ANS responses as evidenced by the GSR. These responses did not differentiate between depression and dysthymia, which supports the argument that they may not be distinct disorders. The GSR did differentiate between affective and behavior disorder groups, and between controls and the psychiatric patients as a whole.^ A profile of the ANS responses of psychiatric patients shows that, initially they have smaller responses but take longer to habituate when comparing the responses of current information to new information processing. The psychiatric group in general is seemingly less excitable, yet their responses don\u27t dissipate as quickly. This points to dysregulation in the ANS of the patients. In the controls, the responses are intense, and then dissipate quickly.^ In addition, psychiatric patients respond faster to lower levels of stimulation, and there seems to be no carryover effect--they don\u27t benefit from the first trial (70) into the second (90)--and it takes longer to respond to a greater stimulus. Controls show decreased sensitivity as a function of practice (i.e. they habituate). But psychiatric patients (behavior disorder especially) continue to respond to stimuli which they should have habituated to. This fits in with the nature of destructibility in a behavior disorder diagnosis.^ There was no support of laterality, this may be because it is a peripheral measure instead of a central measure of brain function, or because of the age of the children, effects may not yet be evident.^ The GSR is a better indicator of emotional state than subjective self-report.