The founder of Aussie adtech start-up Unlockd, Matt Berriman, has stepped down as CEO to focus on his mental health.

Berriman announced his decision to step down from the business he started three years ago via an open letter published yesterday on Medium, in which he bravely revealed he has been battling bipolar disorder for the last 15 months.

“It has not been an easy journey [building Unlockd], and as many of my fellow founders can attest to, it’s required me to pour blood, sweat and tears (and all of my money) into the business,” he wrote.

“Throughout the journey I began to experience symptoms, which I attributed for far too long to stress, lack of sleep and the start-up roller-coaster. What I did not know at the time was I was fighting a battle with bipolar disorder.

“Over the last 15 months, despite continuous and multi-faceted treatments, I’m still struggling to return to my optimal holistic health, and as a result, I now need to put a larger commitment in place to concurrently prioritise my health with my commitment to Unlockd.”

Berriman said he will instead take on a role as executive director of Unlockd, focusing on major shareholder relations, overall strategic direction and corporate development.

“This will allow me to continue influencing the growth and future of the business, whilst also giving me the required space to make my health a priority,” he explained.

“This has been an agonising decision professionally and personally, especially knowing the public nature of our business and those that surround it. However, great companies don’t rely on one person, and Unlockd is no different.”

Unlockd’s chief operating officer, Jane Martino, will replace Berriman as CEO.

“This is a role she has effectively been playing for some time now behind the scenes as I continued balancing my own personal health challenges with being the founder and CEO,” Berriman said.