Altered fronto-temporal connectivity in pediatric bipolar disorder
MedWire News: Children with bipolar disorder (BD) have altered task-independent functional connectivity in fronto-temporal brain regions associated with working memory and learning, research suggests.
"Recent data suggest that the incidence of pediatric BD has risen 40-fold in just 1 decade, with over 20% of all minors discharged from psychiatric hospitals now diagnosed with BD," explain Daniel Dickstein (Brown University, Providence, Rhode Island) and team.
However, they add: "Determining the validity of this dramatic increase is problematic because current psychiatric nosology is based entirely on clinical history that is considerably more difficult to elicit from children and adolescents than from adults.
"Thus, there is a pressing need for greater neurobiological understanding of pediatric BD."
To investigate whether fronto-temporal dysfunction is implicated in pediatric BD, the team enrolled 15 children, aged 7-17 years, diagnosed with the mental health disorder according to DSM-IV-Text Revision criteria and 15 mentally healthy children without the condition (controls).
The two groups did not differ significantly in terms of age, gender, pubertal stage, or IQ.
Using magnetic resonance imaging, the team assessed task-independent spontaneous resting state functional connectivity (RSFC) in the left dorsolateral prefrontal cortex (DLPFC), amygdala, and accumbens.
Primary analysis revealed that children with BD had significantly decreased RSFC between the left DLPFC and the right superior temporal gyrus compared with controls.
Secondary analyses showed that children with BD and controls had opposite phase relationships between spontaneous RSFC fluctuations in the left DLPFC and right superior temporal gyrus.
Specifically, in controls, increased spontaneous blood-oxygen level dependent signal in the left DLPFC was associated with simultaneous increases in the right superior temporal gyrus and vice versa. The opposite was true for children with BD, with increased spontaneous activity in the left DLPFC associated with simultaneous decreases in the right superior temporal gyrus.
Dickstein and team conclude in the journal Biological Psychiatry: "Our data indicate that pediatric BD is characterized by altered task-independent functional connectivity in a fronto-temporal circuit that is also implicated in working memory and learning."
They add: "Further study is warranted to determine the effects of age, gender, development, and treatment on this circuit in pediatric BD."
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By Mark Cowen