Mental disorders including neurodevelopmental diffculties are frequent, creating a substantial disparity between the demand for mental health care and the available resources. The potential of therapeutic technologies to address this treatment gap is immense, offering scalable solutions to enhance access. Yet, the intricate nature of mental disorders, woven with diverse risk factors, poses challenges to a comprehensive understanding of their mechanisms and assessment of this potential. Current assessments of mental disorders heavily rely on the expertise of trained clinicians, making it imperative to explore innovative avenues such as "digital phenotyping" to capture nuanced behaviors. However, integrating technology into healthcare encounters obstacles exacerbated by the divergent cultures of medical professionals and engineers. While technical feasibility is a priority for engineers, it often needs to match the acceptability standards set by healthcare professionals. Navigating the complexity of the healthcare ecosystem compounds the challenge of identifying precise needs. Furthermore, the time-intensive nature of clinical research methods hinders the swift evaluation of effcacy. To surmount these hurdles, we advocate for the incorporation of user-centered design methodologies and participatory research in the development of therapeutic technologies. This chapter delves into the multifaceted challenges of designing technologies, such as robots, for therapeutic programs focused on individuals with neurodevelopmental disorders. By proposing solutions that prioritize participatory co-design environments, we aim to empower individuals from diverse backgrounds to collaboratively support those undergoing therapy with technology, ensuring its effcacy and benefts.