A-87 Regional Cerebral Blood Flow in Self-Reported Somatic Anxiety

Objective To identify regional cerebral blood flow (rCBF) differences between individuals who self-reported either low or high symptoms of somatic anxiety. Method Individuals who reported low levels of somatic anxiety (0-20th percentile;n = 8962,Mage = 39.2,39.2% female,62.6% Caucasian) and individuals who reported high levels of somatic anxiety (80-100th percentile;n = 6427,Mage = 40.9,39.0% female,69.5% Caucasian) were selected from a deidentified adult clinical outpatient database. Those with comorbid diagnoses were included. Significant differences (alpha = 0.001) were found for age [t(15387) = 6.3], and race [χ2(15) = 119.4] between groups and therefore were controlled. Results Significant rCBF differences were noted bilaterally in the frontal lobe [left: F(1,15,384) = 16.4; right: F(1,15,384) = 13.2] and motor-sensory strip [left: F(1,15,384) = 4.3; right: F(1,15,384) = 5.1]. Group means comparisons indicated higher perfusion in the frontal lobe of the high levels of somatic anxiety group. Lower perfusion was found in the motor sensory strip of the high levels of somatic anxiety group. No significant differences were found bilaterally in the cerebellum, limbic system, basal ganglia, vermis, or occipital, parietal, or temporal lobes. Conclusion Results indicated that individuals who report higher levels of somatic anxiety have higher perfusion in the frontal lobes and lower perfusion motor-sensory strip. Previous literature SPECT studies have found a link between individuals with panic disorder and increased activity in the right medial and superior frontal lobes. No research was found for anxiety in the motor-sensory strip. Limitations included the reliance on self-report measures of anxiety in place of clinical measures and the potential mediating effect of medication on somatic symptoms. Future research should examine perfusion in the motor-sensory strip, use clinical measures of anxiety, and control for mediation use.