Background/Objectives: Mindfulness-based interventions (MBIs) have emerged in recent years as a strong candidate for the treatment of a range of difficulties faced by individuals with autism spectrum disorder (ASD), including cognitive, emotional, and social aspects. Therefore, we aimed to conduct a review that systematically examined the efficacy of MBIs for individuals with ASD and their caregivers. Methods: This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Our literature search was conducted within the MEDLINE database. We included in the review only longitudinal or intervention studies focusing mainly on mindfulness principles, while we excluded mixed intervention studies. We only included studies that explicitly utilized quantitative methodologies for evaluating the outcomes of the interventions, including mental health indices (e.g., stress, anxiety, depression) and assessments of cognitive and social skills (e.g., attention, prosociality). We conducted also a risk of bias assessment through the method of the Cochrane risk of bias tool for intervention studies ROBINS-I. Results: Thirty-seven studies were included in the review, and we grouped the studies by the targets of the interventions, i.e., adults (n = 12), children and adolescents (n = 9), caregivers and medical staff (n = 13), and combined intervention for both children/adolescents and their parents/caregivers (n 5). The reviewed papers seem to support the feasibility and utility of mindfulness interventions for persons with ASD and their caregivers, but any recommendations based on this body of evidence should be made with caution due to the overall low quality of the studies conducted so far. Conclusions: The review reveals a positive outcome, including the alleviation of psychological distress, reduced behavioral problems, and enhanced cognitive and social skills in individuals with ASD. Despite such promising results, the review notes a limitation in the scarcity of MBIs for young patients, emphasizing caution in universally endorsing the existing literature. Moreover, the results underline the urgency of the exploration of tailored interventions for different ASD subgroups, considering varying levels of autism, and expanding support to teachers in educational settings.
