Adolescents and adults with HFASD represent a complex and underserved population. Of the studies completed to date, findings suggest that this subgroup of adolescents and adults faces a multitude of psychiatric and psychosocial issues, alongside significant challenges in accessing services. Social skills deficits for individuals with HFASD persist into adulthood, and adults appear to be at heightened risk for developing depression, low self-esteem, and anxiety. Despite this, very few studies have examined treatment patterns and interventions (pharmacological and psychosocial) for adolescents and adults with HFASD. Evidence is beginning to emerge for interventions targeting this population, including CBT, MBT, and SST, but further large-scale studies which compare the effectiveness of, for example, CBT or MBT versus other treatment options (e.g., medication, counseling, etc.) are required and the need for mental health clinicians trained to apply these techniques is now.
In developing interventions for these individuals, programs must consider what adolescents and adults want. For example, adolescents and adults with HFASD may be more interested in interventions targeting vocational opportunities than interventions targeting social skills. Individuals with HFASD and their family members must be viewed as valuable contributors and fully engaged in this process. Further, researchers must look at issues of service cost and efficiency when evaluating the impact of interventions .
The large majority of adults and adolescents with HFASD live at home with their families and, of those employed, most obtain jobs in low level, poorly paid, sheltered or supported employment. It is not surprising therefore that the parents of these teens and adults report a number of challenges and concerns related to future independence and availability of appropriate services and supports.
Together, findings point to a number of important practice recommendations. First, developmental disability agencies or agencies supporting individuals with ASD must partner with community mental health agencies to help train, mentor, and build capacity to care for this population across the lifespan. It is important to note that many clinicians working within community mental health agencies already have the skills to effectively deliver this care, but programs either preclude their ability to do so or they lack the confidence to work with this population. Second, there is a critical need for community mental health agencies to review their exclusion criteria to include persons with ASD. For example, agencies providing care for persons with mood or anxiety disorders should not exclude individuals on the basis of a diagnosis of ASD. Community mental health agencies have the resources and expertise in mental health, along with the programs to care for individuals with mental health issues (e.g., vocational programs, counseling, and therapies), but will need guidance from developmental disability agencies to successfully adapt these programs for adults with HFASD. Third, developmental disability agencies must reevaluate their inclusion criteria to include persons with HFASD, regardless of IQ, and across the lifespan. Organizations must work together, combining expertise in ASD from developmental disability agencies with knowledge and resources from community mental health agencies. Fourth, there is a need to study and identify programs and supports that are most effective in both school and community settings. To do this will require a full continuum of mental health services including counseling, vocational support, inpatient services, and outpatient services. It will also require a network of experienced clinicians and community partners. Many of these efforts are already underway in pediatric settings; however, these same efforts are required in adolescent and adult mental health services. Finally, there is a need to prepare and equip older youth with HFASD for the transition to adult services. A number of key recommendations and principles can be gleaned from the broader ID education/vocational literature  and from studies of individuals with ID transitioning from the pediatric to the adult medical system [115, 116], many of which could be tailored to persons with HFASD. For example, the use of meaningful transition tools and the importance of transition workers, protocols, and policies [118, 119] are required.