The world seems more burdened with large-scale global problems than ever before. One such challenge is to reverse the growing incidence of mental health issues, particularly in our cities. Traditional approaches to tackling such major global challenges has come from specific sectors and siloed organizations. These ‘matters of concern’ however are interdisciplinary in nature, and map closely to what those in the design world have attempted to frame as ‘wicked problems’. This article explores the value of design thinking and focuses on five key attributes that designers have in leading projects that attempt to tackle these major global matters of concern. Namely, that designers are: Naturally interdisciplinary, multi-specialists, comfortable with uncertainty, action-led, and people-centered. A case study is explored where designers have been engaged to tackle mental health issues in Derry/Londonderry, Northern Ireland. The paper ends by identifying opportunities and challenges for designers in the future.