Alberta Party MLA Karen McPherson has announced she will not seek re-election.

McPherson was elected under the NDP banner in 2015 in the riding of Calgary-Mackay-Nose Hill but left the governing party in 2017 to sit as an independent.

At that time, she said she was disappointed about the lack of transparency by the NDP regarding allegations of sexual misconduct against two unnamed party MLAs.

She joined the Alberta Party later in 2017.

McPherson said on Wednesday that she has struggled with anxiety and depression during her time in office.

"I very deeply believe our society can only be improved by the increased participation of women, of all perspectives, in the political arena. But I find that the commitment required of public servants is beyond my capabilities right now," she said in an emailed statement.

"I have grappled with the lack of balance between the demands of the role of an MLA and my sense of responsibility to my family and myself, especially as my elderly mother, who recently completed radiation for lung cancer, recovers from her treatment. I have struggled with depression and anxiety throughout much of my time in office because of this lack of balance, especially during the time my father was very ill before he passed away in 2016."

McPherson urged Albertans to focus on what unites them and to not "let fear" guide their vote in the upcoming election.

"Vote for people who inspire you and who take the time to really listen to what you care about, and who will speak up when they see that something isn't right," she wrote.