PHOTO © NETFLIX

A word of advice: If your child starts saying things like, “I don’t think I am myself,” it may be time to seek professional assistance.

Of course, some may decide they have so many skeletons in their own closets that they’re better off riding the impending wave of madness than confronting the past. Such is the ill-fated choice of Sarah (Sarah Snook) in “Run Rabbit Run,” a slow-burn thriller about a very unnerving child and unresolved trauma.

Sarah’s grappling with the loss of her father and a continued estrangement from her mother (Greta Scacchi), who lives under constant care for her advancing dementia. Her ex-husband Peter (Damon Herriman) is a perfectly capable co-parent, but Sarah’s afraid that any crack in her single-mom armor will cost her custody of precocious Mia (Lily LaTorre), an only child with a hair-trigger temper and a bizarre affinity for a stray rabbit.

When Mia starts demanding to see her grandmother, Sarah is confused. “Isn’t it a bit hard to miss people you’ve never met,” she asks. “I miss people I’ve never met all the time,” Mia calmly replies.

Again: Now is the moment for counseling.

When Mia starts insisting that she isn’t really Mia at all, however, things get darker and more desperate. “Run Rabbit Run,” directed by “Handmaid’s Tale” veteran Daina Reid and written by novelist Hannah Kent, takes its time delivering on its mysteries; while it’s relatively short, not much happens for a good while.

Perhaps that’s because the action we do get is so troubling.

“Run Rabbit Run” is no gory slasher or twisting head trip; this is the older kind of thriller, the kind that uses secrets and boiling anger as its currency. That can make it feel a bit out of time, but a strong lead performance and pervasive, chilling atmosphere are enough to keep you watching.

Just don’t expect a happy ending. Not all catharsis is positive, and not all secrets should be revealed.

My Rating: 6/10

“Run Rabbit Run” is now streaming on Netflix.