National Mental Health Commission chief executive Christine Morgan said 2021 was not the "fresh start" people had expected after the challenges of 2020.

"We found the courage to support ourselves, our loved ones and our communities through many hardships last year, but it's a bit different this time as many of us are running close to empty emotionally and mentally," Ms Morgan said.

"It's absolutely understandable that many Australians are experiencing pandemic fatigue at this time, but it's important to realise that we can overcome it."

Warning signs of pandemic fatigue include irritability, anxiety, low energy, restlessness, feelings of hopelessness and dread or feeling like you don't have anything to look forward to.

Ms Morgan urged people to watch out for withdrawal from others, difficulty sleeping, lack of motivation and increased use of alcohol or other substances.

She said it was important to exercise and take breaks regularly, reach out to others, be aware of how news intake impacted you, and do things you enjoy every day.

"It's not only okay to take time out to do something that brings you pleasure, it's actually a really important way to help us rebalance and re-energise," she said.

The commission's chair Lucy Brogden said: "Never underestimate your ability to have a positive impact on someone's life. Others might see you prioritising your mental health and decide to do the same for themselves."

Australian Associated Press