Think of mental health and a list of mental illness often springs to mind – there's depression and anxiety, eating disorders and addictions, schizophrenia and bipolar disorder to name just a few.
Efforts to raise awareness of mental illness mean most of us are now somewhat familiar with the more common mental disorders, even if we've never had the personal experience of one.
But in recent years, both researchers and clinicians have been moving away from viewing mental health in terms of the presence or absence of symptoms. Instead, they have been seeking to discover what it means to be in good mental health, and what we can do to foster our own mental wellbeing.
According to Tim Sharp, founder and Chief Happiness Officer at The Happiness Institute, the shift has been an important one. Rather than spending most of his time stopping people from being at their worst, he now devotes much of his working life to ensuring people are at their best.
Psychologist Martin Seligman has been raising the profile of positive psychology over the past two decades.
Seligman's notion of good mental health boils down to five key domains that together form the acronym PERMA: positive emotions, engagement, relationships, meaning and purpose, and accomplishments. However, other researchers believe additional factors also play a role.
Felicia Huppert, director of the WellBeing Institute at the University of Cambridge and Professor of Psychology at the Institute for Positive Psychology and Education at the Australian Catholic University, has been studying mental wellbeing for more than two decades. She describes mental health as being a spectrum.
"At one end are the common mental disorders [of anxiety and depression] and at the other end is positive mental health, or flourishing," she says.
To define what it means to flourish, Huppert reasoned that attributes of positive mental health would be opposite those that define poor mental health. By looking at internationally agreed measures of depression and anxiety and defining the opposite of each symptom, Huppert distilled a list of 10 features of positive wellbeing.
This list includes the five PERMA attributes, as well as emotional stability, optimism, resilience, self-esteem and vitality.
Regardless of the definitions, evidence shows that a healthy mental state is something to strive for.
"We know that when you have a high level of wellbeing, all sorts of other things go along with that that are really great, like better learning, better relationships, greater productivity, and better health," says Huppert.
Although positive mental attributes and symptoms of common mental illness fall at the opposite ends of the mental health spectrum, they are not merely different sides of the same coin. Having good mental health is not the same as being without poor mental health.
This is perhaps best illustrated by another of Huppert's studies. In the study, over 6000 people living in the UK completed surveys on their general wellbeing, and on whether or not they experienced psychological symptoms. When participants were followed up after seven years, Huppert found that lacking a positive mental state was a better predictor of mortality than the presence of psychological symptoms.
Huppert's study is backed by an analysis of 150 studies of wellbeing that comes to the same conclusion: good mental health can affect your health in ways that isn't explained by a simple lack of poor mental health.
But the analysis also found that some aspects of your health are more likely to be influenced by wellbeing. While wellbeing appeared to have a positive impact on measures of immune system function and tolerance to pain, no effect was seen in people with cardiovascular conditions. Although another study found that positive psychological wellbeing can reduce the risk of developing cardiovascular disease in the first place.
But it's not just you who is likely to benefit if you have positive mental health, there are also benefits for the community.
"When we have high levels of wellbeing, we are more pro-social," says Huppert. "People who feel happier and more satisfied are much more likely to be kind, to be tolerant, to be inclusive. So that's a direct way in which society benefits."
There also appear to be economic benefits as well. Sharp, who works with organisations to promote a culture of optimism and mental wellbeing in their employees, says that these businesses outperform comparable businesses that don't deliberately foster employee wellbeing.
A number of practices have been shown to improve our mental health.
Mindfulness: Mindfulness, which emerged out of the Buddhist tradition of meditation, is a practice of drawing one's attention to the present moment, focusing on emotions, thoughts and sensations in a non-judgemental way. Mindfulness has been shown to be effective at improving mental wellbeing, behaviour regulation, and interpersonal relationships.
According to Huppert, who studies mindfulness, a key to mindfulness practice is awareness. If we are aware that we are becoming angry, for instance, we have a greater ability to make a choice of how to behave in response to that emotion.
Sharp also considers awareness of our emotions and thoughts as being crucial to fostering an optimistic outlook on life.
"Most people operate most of their time on automatic pilot," he says. "Most of their thoughts and beliefs are unconscious and automatic."
By learning to deliberately notice what thoughts we are having, and then being able to question whether or not they are helpful to the situation at hand, Sharp believes we can learn how to be more optimistic over time.
Gratitude diary: Another useful exercise for fostering optimism is a gratitude diary. Listing three things to be appreciative or thankful for at the end of each day can help us to view life from the glass-half-full perspective more often.
Optimism: Sharp draws a clear distinction between fostering optimism and simple positive thinking.
"Real optimism is about focusing on the positive, but it's also important that it's grounded in reality. It's not about pretending everything's fantastic if it's not."
The idea behind Sharp's brand of optimism is to promote thoughts that will help to make the most of a bad situation or find a realistic solution to a problem, rather than just sweeping a problem under the carpet.
Realistic expectations: These are also important, according to Sharp. "No-one's happy all of the time, and no-one will have a positive attitude all of the time."
Negative life events can strike anyone. The death of a loved one, loss of a job, or onset of serious illness can all take their toll on mental wellbeing. This is one reason that it's important to focus on aspects of our life that are within out control, according to Kaarin Anstey, Director of the Centre for Research on Ageing, Health and Wellbeing at the Australian National University.
"There's a lot you can do to improve your happiness and your sense of mental wellbeing," she says.
Social engagement: Anstey points to social engagement and activities such as volunteering as factors that can help to promote good mental health. She also says a healthy diet, exercise and getting adequate sleep play a role.
Many of these same factors protect our cognitive health, something that Anstey also considers central to mental wellbeing.
Huppert, who is studying the impact of a mindfulness program in schools, would like to see mental wellbeing and practices such as mindfulness encouraged as early as possible so that people can reap the benefits as they mature into adulthood.
"Anyone can learn at any stage, at any age," she says. "But the earlier the better."