The TV presenter revealed that he discovered the diagnosis after being arrested on suspicion of drink driving in March 2018.
“I’ve got ADHD. I don’t mind talking about that,” he said, adding: “I never knew that until afterwards. I was so thoroughly examined and diagnosed, I found stuff out about me I hadn’t addressed for years.”
He stated that his diagnosis “made sense” as it has "a lot of links to alcohol-dependency”.
McPartlin, who has just returned to the side of presenting partner Declan Donnelly for the audition stages of ITV series Britain’s Got Talent, continued: “There’s a lot of characteristics that held me in good stead working in live television. Richard Bacon said the same.
“In my job, having what they call ‘popcorn thinking’ is good because it means you can jump from one thing to another. Professionally, it’s brilliant. Personally, I’m all over the place.”
McPartlin took a break from presenting while he treated his addiction to alcohol and painkillers in rehab.
Over the weekend, Donnelly announced McPartlin’s return to crowds at the London Palladium, saying: “We’ve got the judges back, the golden buzzer is back, and someone else is back. My co-host for the series, would you please welcome... Mr Ant McPartlin.”