The study found that although the majority of UK journalists use social media as a professional tool, the number using social media for four or more hours a day has declined from 24 per cent in 2012 to 13 per cent in 2014.
The findings suggest that journalists use social media for specific tasks, rather than being constantly switched on to social platforms.
The research shows that PR professionals are the most important sources for journalists on social media, followed by experts, academics, other journalists and media outlets.
Email is the most widely used communication method between PRs and journalists, followed by the telephone and social media. The number of respondents recieving phone calls from PRs has decreased from nearly 60 per cent in 2013 to 38.6 per cent in 2014, while social media have increased from 18.5 per cent to 32.4 per cent.
Four out of ten respondents said that information from PRs enhanced the quality of their reporting, however less than half thought that PRs were reliable sources of stories.
Twitter remains the most popular social media site for journalists, with 75.1 per cent of the vote, followed by Facebook (56.7 per cent), Google+ (41.2 per cent), Instagram (24.9 per cent) and Hootsuite (24.7 per cent).