About half of all Australians are more stressed because of the coronavirus pandemic and the lockdowns have made almost as many lonely or isolated.
Younger Australians are the most likely to have found their relationship deteriorating during the crisis while parents were more likely to have got on better with their partners.
Researchers say the survey findings underline the mental health toll of the crisis.
The latest data is from a long-running Australian National University study of the pandemic’s wider effects, surveying more than 3200 people.
“Australia has been very fortunate during the COVID-19 period, with low rates of infection and mortality,” co-author Nicholas Biddle said on Wednesday.
“However, that does not mean that there have not been large negative effects on other important outcomes, like our relationships, sense of financial security, stress, and loneliness.”
The deterioration in relationships and increased loneliness were directly associated with worsening mental health, he said.
Australians aged under 45 were still under serious psychological distress compared with pre-pandemic times.
More than half of this age group said they felt more stressed.
Three in five of those aged between 18 and 24 said they were lonely at least some of the time.
* 47 per cent of Australians surveyed were more stressed because of COVID-19
* 32 per cent said their financial situation had worsened over the past three months
* Almost 18 per cent of all men and women said relationships had worsened
* 24 per cent of younger Australians said their relationships were worse
* 31 per cent of women and 25 per cent of men said their relationships had improved
* 33 per cent of parents with a child at home said relationships were better.