Anxiety disorder is likely caused by an interaction of multiple loci in brain, rather than a single locus. Hyperactive neurotransmitter circuits between the cortex, thalamus, amygdala, and hypothalamus are responsible for production of anxiety symptoms. Familial studies performed on anxiety disorder suggested that anxiety disorder should be caused by genetic etiology. Numerous linkage and association studies showed different genetic loci of anxiety disorder. Candidate genes have been focused on important neurotransmitters, neuropeptide, or genes affecting neuronal growth, development, protection or apoptosis. Anxiety disorder has various symptoms and comorbid diseases in family or proband. Therefore, further studies focused on symptomatic dimension of anxiety disorder or responses to drugs are required.

Although treatments of anxiety symptom have been available for decades, the biological basis for anxiety disorders in humans is just beginning to emerge. Recently, there is a growing body of literature suggesting that group II metabotrpic glutamate (mGlu) receptors and group I mGlu receptors are important in the physiological and behavioral sequelae associated with stressful stimuli. Moreover, compounds selective for mGlu receptors, particularly mGlu2/3 and/or mGlu5, have proven as effective as classical anxiolytics in various animal models of anxiety without producing many of the unwanted side effects that are typical of current therapies. This article will focus on the emerging preclinical and clinical data that implicate modulation of the mGlu receptors as a potential anxiolytic strategy.

Substantial rates of comorbid anxiety disorders have been found using structured research diagnostic interviews in depressed outpatients. Comorbid anxiety disorders is underrecognized in routine clinical settings, in which clinicians usually use unstructured diagnostic interviews. Recognition of comorbid conditions such as anxiety disorders in patients seeking treatment for depression is clinically important because the presence of these disorders might influence selection of treatment options or predict the chronicity of the depression. A reliable and valid self-report screening questionnaire, such as the Psychiatric Diagnostic Screening Questionnaire (PDSQ), would potentially enhance usual clinical practice as a useful diagnostic aid.

The definite causes of obsessive-compulsive disorder (OCD) are still unknown. OCD has been suggested to be related to many neurotransmitters in brain, such as serotonin, dopamine and glutamate. It has been shown that serotonergic neurons play a crucial role in the pathophysiology of OCD. Recently, it is known that neurotransmitters other than serotonin also play a role in the pathophysiology of OCD, and a series of studies have provided a few evidence that glutamate may be involved in some OCD patients. The purpose of this article was to review the literatures on glutamatergic dysfunction in OCD. We suggest that glutamatergic dysfunction may be implicated in the pathophysiology of OCD.

Object : This study was designed to assess the change of heart rate variability (HRV) during stimulation test among the patients with major depressive disorder. Methods : 15 patients with major depressive disorder (MDD) and 15 normal controls were enrolled in this study. We sequentially measured HRV at baseline, during cognitive stimuli and emotional stimuli. Results : There are significant differences between the two groups in HRV index, TINN on baseline state and under cognitive stimulus. Conclusion : Stimulation protocol using HRV can be useful in estimating autonomic nervous function.

Objectives : To investigate the validity of an abbreviated self-rated Korean version of MINI (Mini International Neuropsychiatric Interview) patient health survey which screening social anxiety disorder, panic disorder, generalized anxiety disorder, and major depressive disorder. Methods : 115 subjects completed MINI and MINI patient health survey. The validity of MINI patient health survey was assessed by whether the results from MINI patient health survey were compatible with the results from MINI or not. The Cohen's kappa value, specificity, sensitivity, positive predictive value, and negative predictive value was calculated for this purpose. Results : The Kappa values of social anxiety disorder (0.60), panic disorder (0.49), generalized anxiety disorder (0.60) and major depressive disorder without other co-morbid disorder (0.59) were at least moderate in strength of agreement. Conclusion : The abbreviated self-rated Korean version of MINI patient health survey has the moderate to good validity in social anxiety disorder, panic disorder, generalized anxiety disorder, and major depressive disorder without other co-morbid disorders. Our result suggests that this instrument might be useful for screening above 4 disorders if it is used under careful supervision of experienced clinicians.

Objective : The present study investigates patterns of consumption of alcohol, cigarettes, and over the counter drugs (OTC) in Korean patients with PTSD and psychiatric patient controls and healthy controls from multicenter hospital samples. Method : Data were collected from 18 hospitals nationwide. Patients with PTSD were compared with nonpsychotic psychiatric disorders control and healthy control subjects on psychometric measures of consumption of alcohol, cigarettes, and OTC drugs. Result : Ninety-three patients with PTSD, 73 patients with psychiatric disorders control, and 88 healthy control subjects were enrolled. There were significant differences in the frequency of alcohol drinking among the three groups ($X^2$=12.93, df=6, p=0.044). Only 3.2% of healthy control subjects drank alcohol more than 4 times a week, but 43.9% of PTSD group and 46.5% of mental disorder controls drank alcohol more than 4 times a week, respectively. Regarding cigarette smoking, there were no differences among the three groups. There were significant differences in uses of OTC drugs among the three groups; 16.7 % in the PTSD group, 14.9% in the psychiatric control group and 1.3% in the heath control group, respectively ($X^2$=11.31, df=2, p=0.004). Conclusion : In this study, patients with PTSD showed significant differences in the frequency of consumption of alcohol and OTC drugs, as compared with healthy controls. However, there were no differences between the PTSD and psychiatric patient control groups. Since all subjects were enrolled from hospital based sample, results may differ in the community samples. Further studies will be needed for the evaluation of substance uses in these groups.

Objectives : By comparing the prevalence rates of suicide-related behaviors (suicide ideation, plan and attempt) between depressive disorder and anxiety disorder patients, we tried to find the characteristics of suicide-related behaviors in these patients. Methods : Four hundred-three patients participated in the study and the prevalence rates of suicide-related behaviors were investigated using Korean version of Mini International Neuropsychiatric Interview plus. Pearson Chi-Square test was used to find the association between depressive or anxiety disorders and suiciderelated behaviors. Results : Statistically significant differences were found between depressive disorder group and anxiety disorder group in terms of suicide ideation ($X^2$=6.173, df=1, p=0.013) and suicide attempt ($X^2$=8.008, df=1, p=0.005). We also found that patients in depressive disorder group were more likely to have suicide ideation (Odds Ratio=2.049, 95% Confidence Interval=1.155-3.635), and attempt suicide (Odds Ratio=4.970, 95% Confidence Interval=1.466-16.845) than patients in anxiety disorder group. Conclusion : These findings suggest that suicide ideation and suicide attempt rates are higher in depressive disorders than in anxiety disorders.