Autistic individuals experience disproportionately high rates of co-occurring mental health conditions, including anxiety, depression, attention-deficit hyperactivity disorder (ADHD) and other psychiatric difficulties, which substantially affect psychosocial functioning and quality of life across the lifespan. These mental health challenges do not arise in isolation but emerge through complex interactions between core autistic characteristics and cumulative psychosocial risk factors such as emotion dysregulation, social exclusion, environmental stress and limited systemic support. Despite growing recognition of these challenges, existing intervention approaches remain fragmented, predominantly symptom-focused and insufficiently responsive to contextual and neurodiversity-related needs. This review critically synthesises contemporary literature on psychosocial risks and intervention gaps associated with autism and co-occurring mental health conditions. The synthesis identifies persistent challenges in assessment practices, service accessibility, workforce preparedness and equity, alongside limited integration of emotion regulation, executive functioning and environmental adaptation within intervention frameworks. Evidence further indicates that community-based supports, transitional care pathways and integrated mental health provision within educational and vocational settings remain underdeveloped, contributing to discontinuities in care and suboptimal outcomes. In response, this article proposes a conceptual psychosocial intervention framework that conceptualises mental health difficulties in autism as outcomes of dynamic interactions across individual, relational and systemic levels. Psychosocial interventions are framed as buffering mechanisms that mitigate cumulative risk and promote adaptive functioning when implemented holistically and contextually. Addressing these priorities is essential to improving mental health outcomes, enhancing social inclusion and supporting life participation for autistic individuals with co-occurring mental health conditions.