Psychophysiological Biomarkers of Stress As Predictors of Behavioral Disturbance in Autism Spectrum Disorder

Background: Many individuals with autism spectrum disorder (ASD) who are non-verbal and intellectually impaired are unable to effectively communicate their internal stress state, which may manifest as problem behavior during times of high stress. This presents significant challenges for those providing care and services for this population. Psychophysiological measures of arousal, such as skin conductance level (SCL), may provide an early indication of proceeding problem behavior, which may eventually be used to intervene prior to the engagement of problem behavior.

Objectives: The present study examined the feasibility of collecting SCL data from severely affected individuals with ASD during lesson time in a school setting at a residential facility for severely affected individuals with developmental disabilities. SCL was examined prior to the occurrence of problem behaviors to determine if a period of time exists prior to when the problem behavior occurred that could be used to intervene. SCL was also examined after the problem behavior occurred to determine how long it takes on average for an individual in the classroom to return to median baseline levels of SCL after the occurrence of a problem behavior. We also explored whether subtypes of SCL responders within the sample differed regarding types of problem behaviors.

Methods: SCL data from 8 individuals with ASD who are non-verbal and have severe intellectual impairment were collected over a 1-year period. SCL data were analyzed once per month for a year prior to engagement of problem behavior as well as after the problem behavior ceased. Also, the SCL data prior to engagement in problem behavior were visually inspected for the presence of different SCL subtypes in an exploratory manner.

Results: An anticipatory rise in SCL only occurred 60% of the time prior to the problem behavior, with an average rise time of 10 minutes between the initial rise in SCL and the engagement in problem behavior. Furthermore, SCL levels after a problem behavior returned to median baseline levels only 45% of the time. Additionally, three different subtypes of SCL response were found, suggesting that different treatment strategies may be effective for each SCL response pattern.

Conclusions: It is feasible to utilize SCL as an indicator of stress in severely affected individuals with ASD who are non-verbal and intellectually impaired. A significant window of opportunity for intervention (10 minutes on average) may exist between the initial rise in SCL and engagement in problem behavior in some people with ASD. Further, almost half of the participants did not return to baseline SCL levels after engaging in problem behavior, reinforcing the importance of prediction and intervention prior to the engagement of problem behavior. Finally, distinct SCL patterns were associated with different problem behaviors, which may have implications for treatment strategies (i.e. cognitive/behavioral vs. pharmacological). Taken together, these results may ultimately help caregivers and practitioners create better personalized, precise treatments that will be more efficient and help increase the quality of life for individuals with ASD.