The field of Global Mental Health (GMH) aims to address the global burden of mental illness by focusing on closing the “treatment gap” faced by many low- and middle-income countries (LMICs). To increase access to services, GMH prioritizes “scaling up” mental health services, primarily advocating for the export of Western centred and developed biomedical and psychosocial “evidence-based” approaches to the Global South. While this emphasis on scalability has resulted in the increased availability of mental health services in some LMICs, there have been few critical discussions of this strategy. This commentary critically appraises the scalability of GMH by questioning the validity and sustainability of its approach. We argue that the current approach emphasizes the development of mental health services and interventions in “silos,” focusing on the treatment of mental illnesses at the exclusion of a holistic and contextualized approach to people's needs. We also question the opportunities that the current approach to GMH offers for the growth of mental health programmes of local NGOs and investigate the potential pitfalls that scalability may have on NGOs’ impact and ability to innovate. This commentary argues that any “scaling up” of mental health services must place sustainability at the core of its mission by favouring the growth and development of local solutions and wider forms of support that prioritize social inclusion and long-lasting mental health recovery.