Perinatal Interpersonal Violence Risk Higher in Schizophrenia

Marilynn Larkin

March 10, 2023

Pregnant and postpartum patients with schizophrenia are three times more likely to experience interpersonal violence, compared with those without schizophrenia, a new study suggests.

In a population-based cohort study that included almost 2 million participants, 3.1% of patients with schizophrenia had an emergency department (ED) visit for interpersonal violence during pregnancy or the first postpartum year, compared with 0.4% of those without schizophrenia.

Among patients who did not self-report interpersonal violence when screened, schizophrenia was associated with an increased risk for a perinatal ED visit for interpersonal violence, compared with absence of schizophrenia (4.0% vs 0.4%; adjusted relative risk [aRR], 6.28).

Dr Simone Vigod

"Having a three- to sixfold increased risk of experiencing violence — either by self-report or being seen in the ED — was very significant," principal investigator Simone Vigod, MD, head of psychiatry at Women's College Hospital in Toronto, told Medscape Medical News.

She advises clinicians to "ask pregnant and postpartum people with schizophrenia whether [interpersonal violence] is happening to them, in a nonjudgmental environment, [and] optimize the supports and services needed to enhance their safety."

The study was published online March 6 in the Canadian Medical Association Journal.

Routine Screening?

The researchers analyzed data from all individuals aged 15–49 years who were listed as female on their health records and who had a singleton birth in Ontario between 2004 and 2018. The primary outcome was an ED visit for interpersonal violence during pregnancy or from the person's delivery date to 365 days post partum. Secondary outcomes included screening for interpersonal violence and disclosure of violence in response to screening.

The investigators adjusted relative risks (RRs) for demographics, prepregnancy history of substance use disorder, and history of interpersonal violence. Interpersonal violence screening and self-reported interpersonal violence during pregnancy were assessed in a subcohort analysis.

A total of 1,802,645 pregnant participants were included in the study, 4470 of whom had

schizophrenia. Participants with and those without schizophrenia were similar in age (mean, 30.62 years, vs 30.26 years) and parity (43.6% vs 43.7% primiparous).

Participants with schizophrenia, however, were more likely to live in a lower income neighborhood (36.5% vs 22.4% in the lowest income quintile), to have comorbid substance use disorders (15.3% vs 1.7%), and to have had an ED visit for interpersonal violence in the 2 years before conception (4.8% vs 0.7%). They were also more likely to have comorbid psychiatric and chronic medical conditions.

A total of 137 patients (3.1%) with schizophrenia had a perinatal ED visit for interpersonal violence, compared with 7598 (0.4%) of those without (RR, 6.88; aRR, 3.44). Results were similar when calculated separately for the pregnancy period (aRR, 3.47) and the first year post partum (aRR, 3.45).

Although pregnant people with schizophrenia were as likely to be screened for interpersonal violence as those without (74.3% vs 73.8%; aRR, 0.99), they were more likely to self-report it (10.2% vs 2.4%; aRR, 3.38). Among those who did not self-report interpersonal violence, schizophrenia was associated with an increased risk for a perinatal ED visit for interpersonal violence (4.0% vs 0.4%; aRR, 6.28).

"Specialized violence prevention, screening, and management protocols for pregnant and postpartum patients with schizophrenia are warranted to mitigate this risk," the authors wrote.

Among the study limitations noted by the authors was that people who experienced interpersonal violence but did not present to the ED were not included. In addition, the perpetrators of the interpersonal violence could not be determined, and the researchers did not have access to clinical management plans or to all potential confounders, including key potential factors, such as race or ethnicity.

No Differential Treatment

Commenting on the findings for Medscape, Carol Tamminga, MD, chair of psychiatry at UT Southwestern's O'Donnell Brain Institute in Dallas, Texas, and chief of the university's translational neuroscience division in schizophrenia, agreed with the bottom-line findings that "we ought to treat schizophrenia better and that we ought to give people with schizophrenia sufficient attention."

Dr Carol Tamminga

The study raises some concerns, she said. From a computational standpoint, she is concerned about comparing 1.8 million people without schizophrenia to 4470 with schizophrenia — two very different-sized groups — instead of selecting a similarly sized representative sample from the no-schizophrenia group.

She also questioned the percentage of times that a person with schizophrenia visited the ED for interpersonal violence. She noted that the percentage is 4.8% within the 2 years before pregnancy, vs 3.1% in the pregnancy and postnatal period, an apparent decrease in frequency. "The 3.1% is more than normal — ie, compared to no schizophrenia — but less than their usual of 4.8%," said Tamminga.

She also noted that "screening can often turn into a reason for differentially treating people with schizophrenia, which we don't want. I'm in favor of some kind of interpersonal violence screening, but not just any time a person with schizophrenia comes to the ED.

"People with schizophrenia are a bit odd sometimes, so it's easy to not spend enough time with them, to try to shirk them and get them out of the emergency room quickly, without doing all the things that you might do for somebody whose neighborhood is a little higher socioeconomic status," she added.

"And they have a more serious medical history than the other participants — more hypertension, more diabetes, more mood and anxiety disorders, and more substance use. For sure, all those conditions should also be attended to in the emergency room and with follow-up treatment," Tamminga concluded.

The study was funded by the Canadian Institutes of Health Research. Vigod and Tamminga have disclosed no relevant financial relationships.

CMAJ. Published online March 6, 2023. Full text

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