PHOENIX -- WNBA star Brittney Griner said she thought about killing herself during her first few weeks in a Russian jail after her 2022 arrest on drug-related charges.

Griner spoke for the first time about her monthslong detention in Russia during an hourlong interview that aired Wednesday night on ABC's "20/20."

Griner's memoir, "Coming Home," is set to be released on May 7.

Griner was detained after arriving at a Moscow airport after Russian authorities said a search of her luggage revealed vape cartridges allegedly containing oil derived from cannabis.

"I wanted to take my life more than once in the first weeks," Griner told ABC's Robin Roberts. "I felt like leaving here so badly."

She decided against it in part because she was afraid the Russian authorities wouldn't release her body to her family.

Her plight unfolded at the same time Russia invaded Ukraine and further heightened tensions between Russia and the U.S. Griner was eventually freed in exchange for Russian arms dealer Viktor Bout.

Griner said before she was released, she was forced to write a letter to Russian President Vladimir Putin.

"They made me write this letter. It was in Russian," she said. "I had to ask for forgiveness and thanks from their so-called great leader. I didn't want to do it, but at the same time I wanted to come home."

She was disappointed when she got on the plane for the trade and Paul Whelan, another American who has been detained in Russia, wasn't with her.

"I walked on and didn't see him, maybe he's next. Maybe they will bring him next," she said. "They closed the door and I was like, are you serious? You're not going to let this man come home now."

Griner plays for the Phoenix Mercury. The WNBA season begins on May 14.