The interview was watched by 11.1 million viewers, and hit a peak of 12.4 million.
The Helpline is a free, confidential crisis hotline that is available to everyone 24 hours a day, seven days a week.
The two-hour special was only beaten by Boris Johnson’s live 4 January speech on the latest lockdown schedule, which was watched by 15.6 million viewers.
The broadcaster also noted that 2.2 million of the show’s viewers came via their streaming platform ITV Hub.