Treating High BP Key to Improved Cognition in Schizophrenia?

Fran Lowry

July 15, 2016

A new study links hypertension to cognitive impairment in schizophrenia, suggesting the possibility that treating high blood pressure may improve outcomes in patients with this mental illness.

In a small study, higher pulse pressure was found to be associated with generalized neurocognitive deficit in patients with schizophrenia in comparison with control persons.

The finding provides support for the role of metabolic abnormalities in the generalized neurocognitive deficits seen in patients with schizophrenia and also suggests that treatment of hypertension may help alleviate cognitive deficits in these patients, study authors Lindsay F. Morra, PhD, and Gregory P. Strauss, PhD, State University of New York at Binghamton, note.

The research was published online July 7 in a communication to Schizophrenia Research.

Novel Adjunctive Treatment

Despite increased rates of metabolic abnormalities in schizophrenia patients and the fact that in the general population, metabolic abnormalities play a clear role in cognitive impairment, few studies have examined the association in patients with schizophrenia.

The investigators explored this association in 27 outpatients with schizophrenia or schizoaffective disorder whose conditions were clinically stable and in 33 psychiatrically and neurologically healthy control persons. All study participants were similar with respect to age, sex, parental education, and ethnicity.

Participants completed a battery of neuropsychological tests, including the Structured Clinical Interview for DSM-IV, the Brief Negative Symptom Scale, the Brief Psychiatric Rating Scale, and the MATRICS Consensus Cognitive Battery (MCCB).

Various metabolic factors were also measured. Blood pressure was the primary dependent measure used to index hypertension. Arterial blood pressure was measured at the brachial level. Fasting blood glucose levels were measured between 8:00 am and 10:00 am after an overnight fast. Waist-to-hip ratio was taken using a cloth measuring tape.

Results showed that higher pulse pressure was predictive of generalized neurocognitive deficit in schizophrenia patients but not in healthy control persons.

In schizophrenia patients, higher pulse pressure was associated with worse processing speed (P < .01), attention/vigilance (P < .01), working memory (P = .04), verbal learning (P = .02), visual learning (P = .02), and global cognition (P < .01).

There was no significant relationship between blood glucose levels and waist-to-hip ratio and cognition either in patients with schizophrenia or control persons.

The authors note that the limitations of their study include small sample size, failure to measure other factors known to affect cognition, such as oxidative stress and inflammation, and the fact that the MCCB is known to be imprecise in localizing circuit level function and in isolating specific cognitive domains.

"Future studies may want to use other approaches such as cognitive neuroscience measures, neuroimaging, and electrophysiology, which evaluate more precise domains of cognitive function," they write.

Current treatment options, which include cognition-enhancing drugs and cognition remediation programs, are of limited benefit for patients with schizophrenia.

The researchers note that their findings may have significant implications for the treatment of cognitive impairment in schizophrenia patients.

"These findings provide support for the role of metabolic abnormalities in the generalized neurocognitive deficit in schizophrenia, and suggest that treatment of hypertension may be a novel adjunctive treatment target for remediating cognitive deficits in schizophrenia," the authors conclude.

Not Enough Information

Commenting on the findings for Medscape Medical News, Raquel Gur, MD, PhD, professor of psychiatry at the University of Pennsylvania Perelman School of Medicine, Philadelphia, said there is "not enough information for us to critically evaluate the significance and potential conclusions that the clinician should take away from this.

"The sample is small, the information on the age of the participants, the past medical history, comorbidity, medications that they are on ― there are so many factors that are not there," she added.

The study was supported by the US National Institute of Mental Health and the American Psychological Association. Dr Morra has disclosed no relevant financial relationships. Dr Strauss has received royalties and consultation fees from ProPhase LLC in connection with commercial use of the Brief Negative Symptom Scale and other professional activities.

Schizophr Res. Published online July 7, 2016. Abstract


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