Now, a Monash University project is aiming to bring cognitive behavioural therapy, a commonly used psychological treatment method, to users' smartphones.

David Bakker​, a doctor of psychology student, and his supervisor, Associate Professor Nikki Rickard, have been developing the app for the past 18 months.

The result is MoodMission​, which the researchers say could help people learn and use better ways of coping with low moods and anxious feelings.

While there are more than 3000 apps targeting mental health on the market, it's been estimated that fewer than 1 per cent of those have been tested for efficacy. Bakker and Rickard hope theirs will be among the first in the world to undergo randomised controlled testing to make sure it is effective.

Cognitive behavioural therapy is designed to help people change unhealthy or destructive habits and behaviours over time.

"MoodMission​ works in a similar way by recommending useful, brief, easily achieved coping strategies to users to help them deal with negative thoughts, feelings, or behaviours," Bakker said.

The app uses the principles of games to engage its users. If people take part in good coping strategies, they will have "completed missions" and be rewarded by the app in an attempt to motivate them further.

Paradoxically enough, Bakker said, technology can often isolate people from support services. "Technology without social purpose can be correlated to negative mental health outcomes."

With this in mind, the researchers have designed the "missions" for people using the app to complete to be as social as possible: phoning a friend, going for a walk or – if people don't feel up to that – simply putting down the phone and sitting quietly on the couch taking deep breaths.

It is designed to be used by anyone, regardless of whether they have been diagnosed with a mental illness, or are taking medication for their illness.

Mental health and wellbeing apps are growing in popularity, with the Australian-designed "mindfulness" app Smiling Mind downloaded to almost 1 million users, including in schools.

But are apps, which essentially rely on self-reporting, a safe way of treating mental illness?

"It's not going to replace face-to-face contact, but it can help people," Bakker said.

"It's so much more private. You don't have to see anyone or admit anything if you use a smartphone. We have quite a deep personal relationship with these little pieces of technology."

The team is seeking financial support through the crowd-funding site Pozible​, to help pay for coding the software.

Although the team has had offers of financial help from companies interested in commercialising the app, Bakker said they had turned these down, and would ensure the app was free so there was no financial disincentive to people using it.

Dr Michael Carr-Gregg, psychologist and managing director of Young and Well Cooperative Research Centre – a not-for-profit organisation that explores the use of technology in managing mental health problems in young people – said apps could be a useful tool but there was no evidence base yet for their effectiveness.

"Just because the app is ahead of the science doesn't necessarily mean that they're not any good. I'm getting lots of patients bringing apps in that they're using already using and finding helpful because they're cheap, they're there 24-7, and as a psychologist I can't be," he said.

"Apps are very much the future of mental health and particularly e-mental health. But people should use them as an adjunct to the therapy that they're doing with their psychologist."

– with Jill Stark