5.5 TRANSCRANIAL PHOTOBIOMODULATION IN THE TREATMENT OF SOCIAL AND EXECUTIVE FUNCTION DEFICITS IN AUTISM SPECTRUM DISORDER

Abstract

No established treatments exist for the core features of autism spectrum disorder (ASD). Transcranial photobiomodulation (tPBM) is thought to enhance neuronal activity and promote cellular plasticity. Recent clinical research interest has focused on its role as a potential treatment in mental illness and neurological conditions including depression and traumatic brain injury. The efficacy of tPBM treatment in ASD remains unexplored. Adult participants meeting the diagnostic criteria for ASD were enrolled to receive twice-weekly tPBM treatments for 8 weeks in an open-label single-group design. ASD symptom severity and executive function deficits were assessed at baseline and endpoint by clinician-, self-, and informant-rated measures. Paired samples t test analyses were performed. Findings were placed in the context of the existing sparse research consisting of clinical trials identified by a detailed MEDLINE literature search with resulting articles assessed for strength of evidence. Finally, interim results from the ongoing 8-week open-label study of daily tPBM treatment in youth with ASD diagnosis are presented. Ten participants (9 males; 30.0 ± 11.9 years old) completed the study. Five participants (50%) met the responder criteria at endpoint. Eight-week transcranial laser therapy (TLT) was associated with significant improvement in ASD severity (Total SRS-2 reduction: –30.6 ± 23, p < 0.001), particularly in Social Awareness (–3.0 ± 1.9, p < 0.001), Social Communication (–10.3 ± 6, p < 0.001), Social Motivation (–5.0 ± 2.4, p < 0.001), and Restricted/Repetitive Behaviors (–7.4 ± 4.1, p < 0.001). Statistically significant improvement at endpoint was shown in Global Assessment of Functioning (GAF) scores (+12.8 ± 4.2, p < 0.001) and Quality of Life Enjoyment and Satisfaction Questionnaire scores (+6.0 ± 7.9, p = 0.02). There were no treatment-limiting adverse events. The adherence rate was 98%. tPBM treatment was associated with improvements in the core features of ASD as well as executive dysfunction, and a significant improvement in overall function. The 98% rate of adherence to scheduled study visits and procedures suggests a high potential of acceptance of this noninvasive intervention. tPBM is a safe, feasible treatment approach and further research into its efficacy in the treatment of the core features of ASD is warranted.