[A search for psychobiological determinants of anxiety disorders].

UNLABELLED: The aim of the study was to search for measurable, objective, and reproducible biological factors such as gene polymorphisms that increase the risk of an anxiety disorder, distinguishing personality traits predisposing to the anxiety disorder. The material comprised 103 patients fulfilling criteria of an anxiety disorder (panic disorders, generalized anxiety disorders, phobic disorders) and a control group of 100 subjects matched for age and free of neuropsychiaric disease.

METHODS

The genes studied were: COMT (catechol-oxygen-methyltransferase), MAO-A (monoamine oxidase A), and 5-HTT-LPR (serotonine transporter). Isolation of human genomic DNA, polymerase chain reaction (PCR) and electrophoresis on agarose gel were part of the study protocol. Anxiety disorders were diagnosed with the Composite International Diagnostic Interview (CIDI). The following psychometric tests were applied: TCI (R. Cloninger's Temperament and Character Inventory), R. B. Cattell's Inventory, C. D. Spielberger's questionnaire, and Beck's depression scale.

RESULTS

There were no associations of COMT, MAO-A, and 5-HTT-LPR gene polymorphisms with anxiety disorders in the study and control groups. A higher level of anxiety as a "status" and as a "trait" were revealed in both groups (p < 0.001). TCI scales and subscales, as well as Cattell's personality factors, demonstrated significant differences between patients with anxiety disorders and controls. Depression was more severe in patients with anxiety disorders (p < 0.001). An association of COMT gene polymorphism with simple phobia (p < 0.004) was revealed. Mutation of 5-HTT-LPR carr tended to be more frequent (p < 0.07) among patients with generalized anxiety.

CONCLUSIONS

Gene mutations that may account for increased risk of generalized anxiety, phobic disorder (simple and social), and agoraphobia were found, as well as gene variants determining temperament traits typical for patients with anxiety disorders. The depression level was higher in patients with anxiety disorders. TCI and Cattell's personality inventory distinguish personality traits typical for such patients.