Bipolar Disorder and Schizophrenia Show Similar Response Inhibition

People with bipolar I disorder (BD) and schizophrenia show similar difficulty with response inhibition according to a study published in Journal of Affective Disorders.

People with BD and schizophrenia both have difficulties with response inhibition, which contributes to impulsive behavior. The researchers wanted to compare this mechanism in people with BD and schizophrenia.

Using data from 66 participants with BD, 32 with schizophrenia, and 48 healthy control participants (HCs), the researchers measured N200 and P300 event-related potential (ERP) components while the participants completed a “Go/No-Go” task. For the tasks, participants viewed 32 facial images with emotional and neutral expressions. Task blocks consisted of an emotion expression as the “go” and a neutral face as the “no go” targets.

The researchers found sensitivity was higher for emotional blocks of faces than neutral blocks, which suggested participants were more able to discriminate emotional from neutral faces when emotional faces were the predominant stimuli (F[1, 145]=65.184; P <.0001). Perceptual sensitivity differed between groups (F[2, 143]=3.639; P =.029). Later analyses indicated both the BD and schizophrenia groups showed reduced discrimination of Go vs No-Go stimuli relative to HCs (HC vs BD: t[143]=-2.328; P =.033; HC vs schizophrenia: t[143]=2.316;  P =.033). BD and schizophrenia groups did not differ from each other in sensitivity (t[143]=0.404; P =.687).

Overall, the researchers concluded both the BD and schizophrenia groups had trouble discriminating between facial expressions. “Given prior evidence that individuals with BD and [schizophrenia] show the greatest emotion recognition impairment for neutral faces (Ruocco et al, 2014), the current task may have been particularly challenging by requiring discriminating a given emotion from neutral faces in each experimental block,” they stated.

In addition to the novel task design, the researchers note they didn’t evaluate medication effects on ERP amplitude. Also, as they integrated data over multiple studies, creating lack of a consistent assessment battery, the researchers were limited in their analyses.

The researchers stated the impairments found in people with BD and schizophrenia “may contribute to difficulty responding appropriately in social affective contexts and relate to mood symptoms, and therefore may be a treatment target in both illnesses.”

Disclosure: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures. 

Reference

Menkes MW, Andrews CM, Suzuki T, et al. Event-related potential correlates of affective response inhibition in bipolar I disorder: Comparison with schizophrenia. J Affect Disord. Published online April 27, 2022. doi:10.1016/j.jad.2022.04.118

This article originally appeared on Psychiatry Advisor