Snap Inc.’s head of content plans to leave the social-media company by year’s end, bringing to at least a half dozen the number of executives who have left the firm over the past year.

Nick Bell, who in a note to employees on Monday said he is taking time off before “deciding on my next adventure,” joined Snap in 2014 from News Corp and oversaw the launch of Snapchat Discover, which features vertical-screen videos and articles from news publishers, including The Wall Street Journal.