Women are happier than men, and that young people are more likely to be distressed, finds a new online survey.
The survey of 309 people, conducted by the Mental Health Association NSW (MHA), also found that spending time with friends or being a member of a club contributed much to an individual's happiness.
It also showed that those unsure whether they would like socialising, "fence sitters", were more prone to mental ill-health.
A majority of women reported feeling happier than men, and they also had more active social lives.
"The report reveals that there is a strong link between participating and feeling happy when socialising with friends or being a member of a club," the Sydney Morning Herald quoted MHA spokeswoman Nataly Bovopoulos as saying in a statement.
"It was also interesting to note that the majority (72 per cent) of the respondents were female, which indicates immediately that women are more likely to get involved than men," she added.
Those who were experiencing a disadvantage from factors such as a financial crisis reported being distressed, as did 18 to 25-year-olds, who were unhappier than older age groups.
The survey, which asks people if they attend religious services or use social networking sites such as Facebook, is part of research into community participation, psychological distress, and mental well-being trends in NSW.
Bovopoulos also said it was possible for people to feel unhappy without being depressed or anxious, however, most people who were distressed reported feeling unhappy.
The release of the research findings on October 1 comes days ahead of Mental Health Week, which begins on October 4.
This year's theme is "Sign up, Link in, Get involved", and aims to promote the positive connection between mental well-being and participating in local communities, clubs and organisations.