Australian tennis star Nick Kyrgios said he had suicidal thoughts, abused drugs and self-harmed during a dark period in his life in 2019.

The controversial crowd-pleaser, who won the Australian Open doubles title last month, posted a lengthy message on Instagram late Thursday detailing his mental health issues.

He linked it to a photo from the 2019 Australian Open in which he pointed to marks on his arm.

“This was me 3 years ago at the Australian Open. Most would assume I was doing ok mentally or enjoying my life… it was one of my darkest periods,” said the 26-year-old.

“If you look closely, on my right arm you can see my self-harm. I was having suicidal thoughts and was literally struggling to get out of bed, let alone play in front of millions.

“I was lonely, depressed, negative, abusing alcohol, drugs, pushed away family & friends. I felt as if I couldn’t talk or trust anyone.”

Kyrgios had a roller-coaster season leading up to the 2019 Australian Open, and was frequently criticised for his on-court antics.

Supremely talented, he was also combustible and earned a reputation for outbursts and meltdowns on court.

He said on Instagram his descent into depression and suicidal thoughts was “a result of not opening up and refusing to lean on my loved ones”.

Kyrgios added that he was now “proud to say I’ve completely turned myself around and have a completely different outlook on everything” and offered to help others who were struggling.

“I know that day to day life can seem extremely exhausting, impossible at times. I understand that you feel if you open up it may make you feel weak, or scared. I’m telling you right now, it’s OK, you are not alone,” he said.

“Please, don’t feel as if you are alone, if you feel as if you can’t talk to anyone, I’m here, reach out.”

Kyrgios, whose ranking has slumped to 137, is the latest in a series of high-profile athletes to speak publicly about their mental health, notably fellow tennis star Naomi Osaka.

The former world number one took a long break last year after a tearful third-round exit at the US Open in September – the culmination of a difficult period where she was plagued by doubt and said she suffered depression.