According to the research firm's figures, worldwide magazine spending fell by 17.4% in Q1, with newspapers registering a drop of 9.1%, while TV and radio were down by 4.7% and 2.5% respectively.
In North America, the US posted a 12.7% contraction in ad revenue, while total regional expenditure through magazines shrank by 22.2%, with TV off by 9.3%, and radio by 8.2%.
Europe was home to many of the hardest hit countries, with adspend tumbling by 28.2% in Spain, 21.2% in Ireland, 19.1% in Italy and 14.7% in the UK.
Television spending levels across the continent also slid by 8.6%, although radio was "fairly stable", posting a contraction of just 0.1% year-on-year.
Asia Pacific also recorded a 2.3% decline overall, although Indonesia's ad market recorded an uptick of 19.1%, while Chinese growth slowed to 2.5%.
However, the 1.0% expansion in TV outlay in the area, combined with a 1.4% improvement in radio revenues, partly helped offset declines elsewhere.
By sector, FMCG expenditure increased by 0.2% in the first three months of this year, while automotive was down by 19.9%, financial services by 16.7%, and clothing and accessories by a further 15.7%.