That is according to the PRCA's latest Digital PR and Communications Report, which surveyed 362 agency and in-house comms professionals.
Of the in-house respondents, 12 per cent said that 'fears of reputational attack on social media' were deterring them from doing more with social media. This figure is up from three per cent last year, and is the largest in the report's history.
Brands also cite lack of staff (40 per cent) and budget (40 per cent) as other reasons why they do not use social media more often.
Despite this, brands are increasing their investment in social media. The report shows that the proportion of budget spent on social is 27 per cent, up two per cent from 2016.
A further 55 per cent said their budget for digital PR and social media would increase over the next 12 months. This is in contrast to four per cent who said budgets would decrease in the next year.
Elsewhere in the report, 51 per cent of brands expected agencies to offer digital crisis management, while the same percentage also expected online reputation management.
However, only six per cent of respondents said they currently used their agencies for these services.
Typically, 59 per cent of PR agencies offer digital crisis management services, while 65 per cent offer online reputation management services, the report shows.
Agencies also typically offer online media relations (82 per cent), social network strategy (80 per cent), and text-based content (79 per cent).
Danny Whatmough, chairman of the PRCA Digital Group and EMEA head of social at Weber Shandwick, said communicating in a digital world required in-house teams and agencies to change the way they work.
He said: "[Over the next 12 months] we will see a movement away from traditional offerings such as web build and a move towards chatbots, social messaging and AI.
"The report shows that the PR industry is leading the charge in many areas, but this is not a time for complacency. The industry needs to continue to evolve to compete."
The report, created alongside PR agency Richmond and Towers, is being launched this evening (24 October) at an event at Golin's London office.