Identification of possible neurobiological trait markers in high-risk subjects for panic disorder

Panic disorder (PD) is a common illness that affects 3.5% of the general population. Several studies suggest that PD patients show psychophysiolgic or neuroendocrine alterations when compared to healthy control subjects. Studies measuring saccadic eye movement (SEM) suggest that PD patients have a decreased GABA-benzodiazepine receptor binding. Moreover, some studies suggest that PD is associated with hypothalamic-pituitary axis (HPA) disturbances. However, so far it is unclear whether these abnormalities represent state or trait specific alterations. To explore whether some of these measures could indicate an increased risk for PD, a study investigating 76 healthy offspring of patients with PD or healthy controls between 7 and 18 years was conducted. MANCOVA for peak saccadic eye velocity (pSEV), latency and accuracy, STAI-C state and trait scores with age and gender as covariates showed a significant overall group effect (F_5,68=3.14, p=.013). High-risk subjects showed impaired accuracies (F_1,72=6.52, p=.013) compared to low-risk controls. Moreover, the high risk group showed significant higher scores in the state (F_1,72=4.36, p=.040) and trait (F_1,72=9.62, p=.003) version of Spielbergers State-Trait Anxiety score. No effects were found for pSEV and latency. In summary, differences in some aspects of saccadic eye movement in subjects at high or low risk for panic were found. Implications for future research on possible predictors on PD will be discussed.