A daily dose of nature can lift the spirits, says a study, and is a lesson in the importance of setting a minimum level of greenery as our major cities expand up and out.

•Dr Michelle Dickinson, also known as Nanogirl, is an Auckland University nanotechnologist who is passionate about getting Kiwis hooked on science. Tweet her your science questions @medickinson.

Look outside your window - what can you see?

If you answered birds, trees and wildlife then congratulations, a new scientific study predicts you are less likely to suffer from depression, anxiety and stress.

More than one third of us live in a large New Zealand city and this has the potential to be good and bad for our mental health.


The economic, cultural and educational opportunities that cities provide can bring positive experiences not found in more rural areas.

However, there are also theories about how urban living can negatively affect our mental well-being from too much sensory overload, overstimulation and feelings of isolation.

The study, published in February's edition of the journal BioScience, surveyed people from different ages, incomes and ethnicities about their neighbourhoods and moods.

They found that those who lived in areas where they could see birds, shrubs and trees around their home had the most positive mental health results.

They also found that those who spent more time outside were less likely to report that they were depressed or anxious.

In New Zealand, depression and anxiety disorders are common.

In the 2012 New Zealand Health Survey, 14.3 per cent of New Zealand adults, or more than half a million of us, had been diagnosed with depression at some time in our lives, and over 200,000 of us with anxiety disorders.

This growing problem has led several researchers to attribute some of the increase in depression with the increasing disconnect between people and the natural world resulting from more urbanised and sedentary lifestyles.

Increasingly, scientific evidence suggests that the availability and quality of local green spaces, active outdoor spaces and community focussed social spaces are associated with greater well-being and lower levels of depression, anxiety, and stress.

What was interesting from the BioScience study was that those who noted the act of just seeing birds in their day had lower stress levels.

From previous research that showed most people are unable to identify the names of most common bird species, they concluded that the type of bird in your neighbourhood is not important, just the fact that there are birds close by can help your mood to be more positive.

Increasing the levels of nature in a city is not a silver bullet for the prevention or treatment of mental health problems in New Zealand.

However, as a country that spends more than a billion dollars a year in mental health services, it is an approach that could be applied in conjunction with existing frameworks such as healthcare, social work and education.

The researchers called their mental health treatment a "daily nature dose" and concluded that frequent experiences with nature provided many mental health benefits to a population.

As Auckland and Wellington struggle with their housing crisis and build up and out to cope with the increasing demand for homes, the question arises as to whether we are building towards an increased burden on our healthcare system.

Urban design has been shown to have a major role in helping to reduce depression and anxiety just by creating designs that support nature in urban environments.

This research has important implications for policy, showing the importance that city planners have in providing potentially huge benefits to our healthcare system just by setting minimum levels of greenery in urban neighbourhoods.

For those who can't change their city view, the research shows that the simple act of adding a bird feeder to a balcony, plants to a window ledge or daily walks around the neighbourhood can help to improve the mental health of those who live there.