My patient was in agony. She was thinking about killing her husband.

She spoke in halting phrases about why she had come for psychotherapy, frequently stopping to ask whether she really was going to murder her husband. Or whether I thought she was a monster. Or if I was going to call the police.

I was not going to call the police.

Instead, I turned our conversation to what she was doing to prevent herself from killing her husband.

She brightened considerably and talked more rapidly. She described how she had first forbidden him from coming near her while she cooked, because this brought up thoughts of stabbing him with one of the kitchen knives. Next, she had asked him to remove the knives and all other sharp objects from the house, such that no weapon would be handy in case she suddenly “snapped” or “lost control.”

But that hadn’t worked to diminish the thoughts, which she was now having constantly. She stopped entering the kitchen altogether, and her husband now did all the cooking (with dull table knives). To prevent herself from mounting a sneak attack, she retreated from a room if he turned his back to her. It was the middle of a hot summer, but she asked him to always keep his shirt on when doing yard work, as the sight of his bare skin made her thoughts of stabbing him more vivid, more upsetting.

In tears, she told me that she loved her husband but wondered whether she should seek a divorce just to protect him from herself. She was already avoiding him so much, and she missed him terribly.

But the thoughts were spreading. She had stopped taking the subway after having images of pushing strangers in front of moving trains. She was avoiding larger family functions due to fears she would hurt her siblings’ small children, possibly during a mental breakdown that she wouldn’t be able to recall later. She worried that perhaps she already had hurt these children, but just couldn’t remember it.

“Am I crazy?” she asked. “Or just evil.”

My patient wasn’t a budding murderer nor was she psychotic: Killers don’t come to psychotherapy to discuss killing, nor are delusional people organized enough to warn their victims to remove weapons in advance. Plus, she had no history of violent assault or indeed any lawlessness.

Perhaps her thoughts should not be taken literally, but rather as a passive yet deep-seated aggression she held against her husband? And her nieces and nephews? And strangers on a train? My patient had explored this possibility at the urging of a previous therapist, where they talked at length about the symbolic meaning behind her thoughts. But this had only made them worse.

Solution

My patient didn’t need to talk more about her violent thoughts; they were not nearly as important a therapy target as were her frantic efforts to avoid having them. She was very clearly suffering from a common form of obsessive-compulsive disorder known as Harm OCD.

I’ve treated adults and children with Harm OCD, and the content of the thoughts is not nearly as important as the actions they take to reassure themselves that they won’t act on them. Unfortunately, the more they attempt to “prove” to themselves that they aren’t murderers, the more OCD raises doubts that maybe, just maybe, the only thing keeping them from acting on the thoughts are the precautions they take. OCD then convinces the sufferer that they are indeed evil, and therefore even more precautions are necessary to keep others safe.

Patients with this sub-type of OCD are terrified to disclose their thoughts to others, including therapists, because so many focus on the violent content and don’t hear that the sufferer is horrified by it and has no intention of acting upon it.

The scientifically well-established therapy for OCD is a type of cognitive behavioral therapy known as exposure and response prevention (ERP). In it, the therapist guides patients to expose themselves gradually to situations that arouse the thoughts (obsessions) while preventing themselves from engaging in the responses they usually take to disprove or prevent the thoughts (compulsions). With repeated exposure practice, patients grow more confident that their terrifying thoughts are not predictive and say very little about who they really are as a person.

My patient was very brave. We started exposure sessions down in the subway, with her standing discreetly behind me as I waited at the front of the platform and trains sped past. Within a few more sessions, she was able to stay near me holding a knife as I read or worked in my office (no, I never feared for my life; not once). Eventually we reached her top fears. She eventually invited her husband into sessions to participate in exposures that they then repeated at home. He was very supportive of his wife’s treatment and, like her, such a sweet and kind person.

ERP works. My patient worked harder. She got her marriage back. She got her life back. And she rode the subway.

Katherine Dahlsgaard is a licensed psychologist in private practice and director of the Food Allergy Bravery Clinic in the Department of Child and Adolescent Psychiatry and Behavioral Sciences at Children’s Hospital of Philadelphia.