Actor Will Poulter has announced that he is taking a “step back” from Twitter and reassessing his “relationship with social media” following abuse from online trolls over his looks in new “Black Mirror” episode “Bandersnatch.” Poulter tweeted Wednesday night that the move was “in the interest of my mental health.”

The British actor, who turns 26 later this month, said he made the decision “in light of my recent experiences.” “I’d like to say a heartfelt thank you to everybody who has watched ‘Bandersnatch’ and for their responses (whatever they may be) to the material we created,” said Poulter, pointedly highlighting the word “material.”

“As we all know there is a balance to be struck in our engagements with social media. There are positives to enjoy and inevitable negatives that are best avoided,” continued Poulter. “It’s a balance I have struggled with for a while now and in the...