Book excerpt: The World Health Organization (WHO) has identified mental health as an integral component of the COVID-19 response. Its rapid assessment of service delivery for mental, neurological and substance use (MNS) disorders during the COVID-19 pandemic, on which this report is based, is the first attempt to measure the impact of the pandemic on such services at a global level. The data were collected through a web-based survey completed by mental health focal points at ministries of health between June and August 2020. The questionnaire covered the existence and funding of mental health and psychosocial support (MHPSS) plans, the presence and composition of MHPSS coordination platforms, the degree of continuation and causes of disruption of different MNS services, the approaches used to overcome these disruptions, and surveillance mechanisms and research on MNS data.