The word “gaslighting” has been thrown around a lot lately, from political rhetoric to bad behavior on “The Bachelor.” But gaslighting is a real, if under-studied, psychological phenomenon—one that can have a serious impact on your mental health. As a clinical psychologist in private practice, I help people recognize the signs and offer strategies to break free.

Reading this list of warning signs, you might find yourself thinking: “Well, that could describe the dynamic between my sister and me sometimes, but she’s not a bad person.” You’re right. Most of us do some of these things sometimes. Instead of individual instances of behavior, look at patterns. When enough of these qualities are present and persistent in a person, chances are you are dealing with a gaslighter.

Their Apologies Are Always Conditional

One of the first things people often notice about gaslighters is that they are masters of the “conditional apology.” You know, when someone says, “I’m sorry you feel that way.” That’s not an apology; the other person is not taking responsibility for their behavior, they’re simply manipulating you into feeling seen by acknowledging your feelings.

They Try to Divide and Conquer

Gaslighters love to pit people against each other, for example: lying to one friend about another, saying that the mutual friend had said something unflattering about them. Gaslighters get a power blast from getting people riled up and fighting with each other, then watch comfortably from the sidelines. They might even offer to step in and help resolve the conflict they caused! They know that this behavior, known as “splitting,” will draw you closer to them—where they can have more control over you.

They Compare You to Others

Gaslighters also use comparison as a way of driving a wedge between people, thus gaining control. Parents who gaslight frequently compare their children to each other—and in unrealistic and blatant ways. The gaslighting parent usually has a “golden child” and a “scapegoat child.” The former can do no wrong, whereas the latter can do no right. This pits siblings against each other, and these feelings of competition commonly extend into adulthood.

Punishment Doesn’t Affect Them

People with Cluster B personality disorders tend to have a different neuron-firing pattern than do other people when disciplined or punished. They also don’t value rewards in the way other people do. This means that punishment and rewards tend to have less of an effect, which results in gaslighters’ being more likely to “do their own thing” without concern about reactions from others.

They Habitually Lie

If gaslighters are caught with the proverbial “hand in the cookie jar,” they will look you right in the eye and tell you they did no such thing. It makes you question your sanity—Maybe I didn’t see them do that after all. This is what they want: for you to become more dependent on their version of reality.

They Isolate You

Gaslighters tend to tell you that your friends and family are bad influences on you, or that you don’t seem happy when you are around those you actually care about. They may also refuse to go to family events with you because “Your family makes me uncomfortable” or some other vague, substance-less excuse. Such a gaslighter is banking on the idea that instead of having to explain to your family why you are attending holiday events without them, you’ll end up spending the occasion alone with them. The more the gaslighter succeeds at isolating you, the more susceptible you are to his control.

They Tell Others That You Are Crazy

Gaslighters will drive wedges between you and other people in all sorts of clever ways. After you leave a job with a gaslighting boss, for instance, your colleagues might tell you that they wondered what was going on, because the boss told them to “tread lightly around that one.” There is no more effective way to discredit you than to tell people that you are crazy. You are now seen as fragile and unstable.

They Expect Special Treatment

Gaslighters feel that standard societal rules, such as politeness, respect, and patience, don’t apply to them. For example, a gaslighter might expect his partner to be home precisely at a certain time and have dinner on the table when he gets home. If the partner doesn’t fulfill this obligation, the gaslighter becomes irrationally angry and may retaliate.

Loyalty Is Required, but Not Reciprocated

Gaslighters require complete and unrealistic loyalty, but don’t expect loyalty from them. (In fact, in romantic relationships, gaslighters are notorious for their infidelity.)

They Refuse Personal Responsibility

It is always someone else’s fault. This is the gaslighters’ mantra. This feature of personality disorders, called ego-syntonic behavior, means that people with the disorder feel that they are normal and everyone else is crazy. They feel their behavior is perfectly acceptable because it meets the needs of their ego. This is one of the reasons that people with personality disorders are so difficult to treat—they don’t think anything is wrong with them or their behavior.

So, what do you if you suspect that someone in your life is gaslighting you? If it’s a friendship or relationship that you can end, do it. If you don’t feel that you can walk away from the gaslighter in question, consider seeking specific forms of counseling—like cognitive behavioral therapy (CBT) or dialectical behavioral therapy (DBT)—that can help you process your experience and minimize the impact on your well-being. Most important: Trust your gut. This person has been trying to erode your self-trust, but you need to follow your instincts here. You wouldn’t be feeling this way if there weren’t something to it.

Excerpted from Gaslighting: Recognize Manipulative and Emotionally Abusive People–and Break Free by Stephanie Moulton Sarkis, PhD. Copyright © 2018. Available from Da Capo Lifelong Books, an imprint of Perseus Books, LLC, a subsidiary of Hachette Book Group, Inc.