This chapter demonstrates the application of design thinking methodology across disciplines to address challenges in mental healthcare, using dementia care as an exemplar. The human-centred design process followed three phases: empathy, ideation, and prototyping. In-depth interviews with patients and caregivers revealed key unmet needs like memory aids and safety reassurance. Collaborative sessions generated technology-enabled solutions to address these needs. Rapid prototyping led to Re-Cog, a mobile app leveraging AI for facial recognition and memory support features. Initial user feedback on Re-Cog was positive, indicating the promise of design thinking for creating patient-centred mental health interventions. While further refinement is required, this exemplar illustrates design thinking’s potential to bridge perspectives from psychology, technology, business, and health to innovatively tackle mental health challenges through a human-focused lens. The methodology provides a model for interdisciplinary collaboration, placing lived experiences at the forefront.