Yes, according to the definition of 'trigger' given by Oxford Dictionaries:
verb [with object]
1.3 (especially of something read, seen, or heard) distress (someone), typically as a result of arousing feelings or memories associated with a particular traumatic experience:
Oxford Dictionaries Online, 'trigger'
Trauma-survivors report that a single word can be sufficient to act as a 'trigger':
It took years for Lindsey to find her way to a therapist, where she discovered that the occasional flashbacks, phantom sensations of being touched, and breathlessness she experienced in the wake of this violation were symptoms of post-traumatic stress disorder. The episodes struck whenever she saw or read words associated with sexual violence: rape, molest, attack, even incest. She’d notice a tingling shock in her chest and “the feeling of fear, maybe a flash of a point of time during my assault, and sometimes it was like he was doing it again,” she says.
Several months ago, a friend of Lindsey’s was regaling her with stories about the movie Room, in which the young female protagonist is imprisoned for years in a shed and repeatedly raped. Lindsey hadn’t seen it, didn’t want to see it; yet when her friend said the word trapped, she detected the unwanted caress of her disorder across her body, felt her pulse begin to race.
... In psychological parlance, a trigger can be any stimulus that transports a PTSD sufferer back to the original scene of her trauma. It might be visual (a red baseball cap like the one an old abuser wore, a gait or facial expression) or aural (a whistle or slamming door). Some people are triggered by the smell of cigarette smoke or traces of a specific perfume. Others react to spoken or written language: words that switch on the brain’s stress circuits, bathing synapses in adrenaline and elevating heart rate and blood pressure.
... When a patient presents with triggers that take the form of words, [professor of clinical psychology] Foa says, she encourages him not to skirt contexts in which those words might materialize.
The Trapdoor of Trigger Words (subtitle: What the science of trauma can tell us about an endless campus debate), Katy Waldman, 5 Sept 2016, Salon.com (emphasis mine)
Within this topic there is some debate over the definitions of terms such as 'trauma', as Professor Foa explains in the same article:
Foa isn’t convinced that those with PTSD would suffer flashbacks “reading accounts of what happened” to fictional characters. A “therapeutic distance” exists, she says, between confronting your past and imagining someone else’s. Even though graphic stories retain the power to disturb, Foa says, “I do not appreciate this idea that people should always decide whether or not they will be made upset. If we act as though they cannot handle distressing ideas, we communicate the unhelpful message that they are not strong.”
Foa’s comment illumines a vast gray area in the trigger warning debate. In the fervor around awareness and empowerment, are university activists using the term trauma too loosely? “I question whether hearing words that have a certain connotation because of our culture or historical context really counts as a trauma,” Kaysen says. “They may be really upsetting, but I don’t know that there’s data to suggest that they would cause PTSD symptoms.”