A+ Treatment/Feasibility of Adapted ESDM-informed Caregiver Coaching Delivered Remotely for Children With ASD (Autism Spectrum Disorder) and ADHD (Attention Deficit Hyperactivity Disorder)

This study will evaluate the feasibility of adapted ESDM-informed caregiver coaching in children with comorbid ASD and ADHD, who are between 36 and \<132 months of age. There will be no study provided medication treatment in this study. Children will either be on ADHD medication prescribed by their own personal provider or will not be taking any ADHD medication (this will be documented by the study). The provided behavioral treatment will be eight \~60-minute sessions in ESDM-informed caregiver coaching delivered remotely through telehealth, for 8 consecutive weeks. The behavioral treatment is provided to children through Early Start Denver Model (ESDM)-informed caregiver coaching strategies, implemented within the child's typical daily routine by the caregiver.

The overarching goal of A+ Treatment is to evaluate feasibility and gather pilot data of remotely-delivered ESDM informed caregiver coaching for children with ASD and ADHD which may inform future combination clinical trials (pharmacotherapy and behavioral intervention). Using an implementation science approach, the investigators will characterize the acceptability, appropriateness, feasibility and fidelity of remote behavioral intervention. Approximately 30-35 participants who are between 36 months and \<132 months of age with comorbid ASD and ADHD will take part in this study, which includes parent coaching sessions completed remotely. Total participation is expected to require a maximum of 20 weeks, including optional remote follow-up at 16 weeks. The A+ Treatment diagnostic and screening visits will generally occur between 1 and 6 weeks prior to baseline. The provided behavioral treatment will be eight \~60-minute weekly sessions of ESDM-informed caregiver coaching delivered remotely through telehealth, for 8 consecutive weeks. Endpoint assessments will be completed after the final coaching visit. No medication will be provided by the study team. The final assessment will be obtained at 16 weeks after baseline.

Eligibility Criteria:
Inclusion Criteria:

* Provision of a parent/guardian signed and dated informed consent form.
* Stated willingness of parent/guardian to comply with all study procedures and availability for the duration of the study.
* Child is between 36 months and \<132 months of age at baseline.
* Child has a confirmed DSM-5 diagnosis of both ASD and ADHD, informed by results of assessments including: an ASD diagnostic assessment (Brief Observation of Symptoms of Autism \[BOSA\], Autism Diagnostic Observation Schedule, 2nd Edition \[ADOS-2\], or TELE-ASD-PEDS, and if applicable the Autism Diagnostic Interview - Revised \[ADI-R\]) and an ADHD diagnostic (a standardized ADHD Diagnostic Interview and the MINI psychiatric diagnostic interview).

Exclusion Criteria:

* If continuing psychotropic (CNS-active) medications, must not have been changed within 4 weeks prior to baseline.
* Significant visual, auditory or motor impairments that would preclude participation in ESDM-informed caregiver coaching or completion of key assessments.
* Inability of the caregiver participating in ESDM-informed caregiver coaching and responding to questionnaires to fluently speak English.
* Study clinician judgment that it is not in the best interests of the participant and/or the study for the child to participate (including presence of psychiatric conditions or psychiatric symptoms in addition to ASD and ADHD that in the opinion of the PI or based on senior clinical review, would confound assessments and/or affect participation in the study).