Boston Celtics legend Paul Pierce has said he suffered from depression and anxiety attacks after being stabbed 11 times.

The attack happened in 2000 outside a nightclub, and two men were later sentenced for the attack. Pierce required emergency surgery on his lung after receiving the wounds, one of which was seven inches deep. In an ESPN story focusing on mental health in the NBA published on Monday, Pierce said the incident left him deeply traumatised for years afterwards.

“I couldn’t be near crowds,” Pierce said, adding that he hired 24-hour security to guard his home after the attack. “If I got in a crowded place, I’d start shaking inside. It took me years to get over that. If I was walking and someone bumped into me or rubbed against me, I’d freak out.”

Pierce said receiving death threats after the attack only increased his anxiety. “So now I’m really paranoid,” Pierce said. “I don’t want to go anywhere. The police sat in the front of my house for months. I was a mess.”

The 10-time All-Star said his anxiety and depression was eased when he talked to a family member about his feelings. “I realized, ‘I should have done this sooner.’ I would tell everyone to get the help they need,” he said. “My depression was bad – really bad. I never want to feel that way again.” He also donated $2.5m to the hospital that had treated him for his wounds.

Once Pierce had recovered from his wounds, he went on to have an outstanding season and led the Celtics to the NBA championship in 2008. He told ESPN concentrating on basketball had also helped him recover. “I think that’s the reason I got back on the court so fast. Me sitting at home thinking about [the attack] didn’t work. I went to every practice, sat on the sideline for hours, because that’s where I felt safe. I didn’t want those practices to end because then I had to go back out there in this world that really scared me.”

Several NBA players have talked about their mental health problems recently. Kevin Love said he had to leave a Cleveland Cavaliers game because of a panic attack, while the San Antonio Spurs’ DeMar DeRozan has spoken about his depression.

Pierce ended his career in 2017 and his jersey was retired by the Celtics earlier this year.