Once in a while, it’s normal to have a fleeting moment where you question your own sanity, like when you’re severely sleep deprived or stressed out. But if a relationship leaves you constantly second-guessing your own instincts and feelings, you may be a victim of a sophisticated form of emotional abuse: gaslighting. Like other types of abuse, gaslighting can happen in all sorts of relationships, including personal, romantic, and professional.

Ben Michaelis, PhD, a New York City-based clinical psychologist, has worked with victims of gaslighting. For one of his patients—we’ll call her Marie—the gaslighting began when her husband shouted another woman’s name during sex. When she tried to discuss the incident with him, he flatly denied what he’d said and told Marie she was hearing things. Marie figured she must have had too much to drink. But then the lying continued: Marie’s husband would change his alibi constantly, and when Marie questioned him, he’d say she was acting delusional. It wasn’t until almost a year later when Marie realized her husband had been hiding an affair the whole time.

Read more