Facial fear recognition responses identified in adolescent bipolar disorder
medwireNews: Patients with adolescent bipolar disorder (BD) show increased neural activity and a prolonged response when presented with fearful faces compared with neutral faces, suggest study findings.
Adolescents with BD often experience difficulty in accurately recognizing emotional facial expressions in others, which may result in socially inappropriate responses. The current study extends previous research showing increased neural activity in the processing of emotional faces, through further investigation of blood flow during facial processing.
"Beyond simple increases and decreases in regional blood flow, improved information about regional variations in the time course of neural processing in ABD [adolescent bipolar disorder]... could help researchers better understand the source of dysfunction and its likely causes, rather than solely learning that dysfunction exists in a particular region," say Ezra Wegbreit (University of Illinois, Chicago, USA) and colleagues.
For their study, published in the Journal of Affective Disorders, the researchers compared shape variations of the hemodynamic response to fearful or neutral faces among 65 adolescent BD patients and 79 mentally healthy controls.
To fully detect changes in the shape of the blood oxygen level dependent (BOLD) response to individual faces, the researchers used a slow event-related design using an affective hemodynamic probe task with appropriate spacing between trials. In addition, informed basis set functions were used to quantify when, how high, and for how long the BOLD responses occurred.
Adolescents with BD showed higher neural activity for fearful than for neutral faces in the bilateral ventrolateral prefrontal cortex (VLPFC), right dorsolateral PFC (DLPFC), left DLPFC/VLPFC junction, and left amygdala.
In addition, adolescent BD patients showed delays in the processing of fearful faces in the right DLPFC/VLPFC junction, right VLPFC, bilateral amygdala, and bilateral caudate. They also showed a prolonged response to fearful faces in the right DLPFC, relative to healthy controls.
The researchers says that this delay further supports the conclusion that adolescents with BD, compared with mentally healthy controls, engaged in extended processing of emotional content.
They also note that this slowed and prolonged processing was associated with the severity of their symptoms and so was driven by their "diagnostic and clinical states, rather than their behavioral performance."
The researchers say that their findings "provided an improved picture of the facial emotion recognition deficits in ABD, potentially leading toward biosignatures of illness status."
They add that "such biosignatures could one day lead to diagnostic tests for bipolar disorder and other mood disorders, and they could provide good criteria with which to evaluate the efficacy of medication and psychological therapies."
medwireNews (www.medwirenews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2013
By Ingrid Grasmo, medwireNews Reporter