Positive emotional processing biases in adolescent BD phenotype
MedWire News: Young people with the common adolescent bipolar disorder (BD) phenotype show positive emotional processing biases, despite increased levels of neuroticism, low mood, and anxiety, UK researchers have found.
Catherine Harmer (University of Oxford) and colleagues explain that, in patients with BD, "the presence of emotional processing biases during mood episodes may be unsurprising, but there are some reports of their persistence in periods of remission."
However, they add: "Studies [of emotional processing] in euthymic bipolar disorder patients may be confounded by residual mood symptoms and the effects of medication."
To address this, the team studied emotional processing in 32 undergraduates with high scores on the Mood Disorder Questionnaire ([MDQ] mean score=8.8) and 30 with low scores (mean score=0.6).
The participants, who were aged an average of 20 years, were assessed for BD and other psychiatric disorders using the Mini International Neuropsychiatric Interview-Plus.
Facial expression recognition, emotional memory, emotion-potentiated startle, and a dot-probe task were used to assess emotional processing in the participants.
Among the participants with high MDQ scores, seven were diagnosed with bipolar II disorder, five with bipolar disorder not otherwise specified, and three with major depressive disorder. All of these participants were in remission according to DSM-IV-Text Revision criteria.
The researchers found that participants with high MDQ scores had significantly higher mean scores on the Eysenck Personality Questionnaire-Neuroticism (8.8 vs 5.4), the State Anxiety Inventory (18.7 vs 15.4), the Trait Anxiety Inventory (21.8 vs 16.7), and the Beck Depression Inventory (7.9 vs 2.9) compared with participants with low MDQ scores.
Regarding emotional processing, participants with high MDQ scores were significantly better at recognizing surprised and neutral faces, with a trend toward impaired recognition of disgusted faces, compared with participants with low MDQ scores.
Furthermore, participants with high MDQ scores had increased processing of positive and reduced processing of negative emotional stimuli across a number of measures, including reaction time for emotional recognition memory and startle eyeblink magnitude, compared with low-scoring participants.
Harmer and team conclude in the journal Bipolar Disorder: "Our results show that positive biases in emotional processing are present in students who have the common adolescent bipolar phenotype."
They add: "These processing biases toward positive emotional information and away from negative emotional information may contribute to the mood-elevation symptoms experienced by the high-MDQ group.
"Therefore, positive emotional processing bias may represent a vulnerability marker associated with the bipolar phenotype."
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By Mark Cowen