Policy makers, planners, researchers and urban dwellers are beginning to understand that health issues in cities are increasingly found in the ‘noncommunicable disease’ realm of mental health. The recent (2016) report by the World Health Organisation aims to address the link between this public health issue and the potential of open, green spaces to have a remedying effect.

There has been sustained historical interest in the links between green spaces and improved health, but the mechanisms and reasons behind such links have not always grounded in empirical evidence. Interest in how green spaces can improve health has recently encountered a resurgence, especially in the context of finding practical urban approaches. Rather than explicitly offering solutions, the new WHO report gathers evidence from studies that have been conducted all over the world to establish similarities and patterns and set the groundwork for a new research toolkit to update this field of study in the context of the 21st century – and importantly, to influence policy and practice.
 
What does the report say about mental health in cities?
The report identifies the potential for the urban environment to engender mental health problems and a lack of general wellbeing as a ‘major public health issue’. Mental health problems can affect anyone in society, at any time in their life, with effects that can be short-lived or have a life-long impact. While it is clearly important to ensure people can receive support and treatment for mental health problems, this is not the only approach, and nor should it necessarily be the first approach. We should look to providing sustainable, preventative measures that reduce the risk of developing mental illness and help maintain good mental health. As Morris et al. (2006) suggests, at the personal level this approach not only improves people's wellbeing; it also reduces the strain placed on healthcare facilities in cities. Furthermore, the report recognises wider socio-economic benefits of good mental health such as a healthier, more productive workforce needing less sick leave due to disorders like depression or anxiety.

The New Urban Agenda is an ‘action-oriented document which will set global standards of achievement in sustainable urban development, rethinking the way we build, manage, and live in cities through drawing together cooperation with committed partners, relevant stakeholders, and urban actors at all levels of government as well as the private sector.’ It was adopted at the Habitat III conference in Quito in October 2016 and one of its stated priorities is to improve human health. So what does this mean for mental health?
 
The Shared Vision for the New Urban Agenda: equal use and enjoyment of cities

The ‘shared vision’ proposes that all inhabitants, without discrimination, are able to inhabit and produce just, safe, healthy, accessible, affordable, resilient and sustainable cities that foster prosperity and quality of life for all. The vision prioritizes people-centered, age and gender-responsive, and integrated approaches to urban development that specifically take into account the needs of women, children and youth, older persons and persons with disabilities, migrants, indigenous peoples and local communities. This is summarised in the document's principles which talk about enhancing liveability, health and wellbeing, safety and public participation, eliminating discrimination, and ‘adopting healthy lifestyles in harmony with nature'.

Where is mental health explicitly mentioned?
 
Within the implementation plan for the New Urban Agenda, commitment 67 for sustainable urban development states:
 
“We commit ourselves to promoting the creation and maintenance of well-connected and well-distributed networks of open, multi-purpose, safe, inclusive, accessible, green, and quality public spaces; to improving the resilience of cities to disasters and climate change, including floods, drought risks and heat waves; to improving food security and nutrition, physical and mental health, and household and ambient air quality; to reducing noise and promoting attractive and liveable cities, human settlements and urban landscapes, and to prioritizing the conservation of endemic species.”
 
What commitments within the New Urban Agenda will specifically help address urban mental health in the context of urban design?
 
While a wide range of the commitments will benefit population mental health, some of the key commitments include:

• Recognition that the spatial organization, accessibility and design of urban space, as well as infrastructure and basic service provision, together with development policies, can promote or hinder social cohesion, equality and inclusion. (25)
• Promotion of safe, inclusive, accessible, green and quality public spaces including streets, sidewalks and cycling lanes, squares, waterfront areas, garden and parks, that are multifunctional areas for social interaction and inclusion, human health and wellbeing, economic exchange and cultural expression and dialogue among a wide diversity of people and cultures, and that are designed and managed to ensure human development and build peaceful, inclusive and participatory societies, as well as to promote living together, connectivity and social inclusion. (37)
• Enabling of participation and engagement of communities and stakeholders in the planning and implementation of policies, including the social production of  habitat. (31)
• Enabling adequate, affordable, accessible, resource-efficient, safe, resilient, well-connected and well-located housing with special attention to the proximity factor and the strengthening of the spatial relationship with the rest of the urban fabric and surrounding functional areas. (32)
• Promotion of equitable and affordable access to sustainable basic physical and social infrastructure for all, including sustainable mobility. (34)

 
The supportive network to deliver the New Urban Agenda: further commitments

• We will support the provision of well-designed networks of safe, accessible, green and quality streets and other public spaces that are accessible to all, free from crime and violence, including sexual harassment and gender-based violence, considering the human scale,  and measures that allow for the best possible commercial use of street-level floors, fostering both formal and informal local markets and commerce, as well as not-for-profit community initiatives, bringing people into public spaces,and promoting walkability and cycling with the goal of improving health and well-being. (100)

• We will work to adopt, implement and  enforce policies and measures to actively protect and promote pedestrian safety and cycling mobility, with a view to broader health outcomes, particularly the prevention of injuries and non-communicable diseases… We will promote the safe and healthy journey to school for every child as a priority. (113)

• We will promote access for all to safe, age-and gender-responsive, affordable, accessible and sustainable urban mobility and land and sea transport systems, enabling meaningful participation in social and economic activities in cities and human settlements, by integrating transport and mobility plans into overall urban and territorial plans and promoting a wide range of transport and mobility options, in particular through supporting safe, affordable and sustainable infrastructure for public transport as well as non-motorized options like waking and cycling – prioritizing them over private motorized transportation. (114)
  

 
With a focus on integrated work between planning, transport, and other departments, clear support for multi-stakeholder partnerships, and an explicit acknowledgment of the impact of cities on mental health, the New Urban Agenda offers interesting potential for investments and action in urban design to improve mental health.

Further Reading: New Urban Agenda