Association between the Daytime Plasma Cortisol Level and Depression Component of Hamilton Depression Rating Scale in Korean Depression Clinic Outpatients / 신경정신의학

OBJECTIVES: There is evidence that Hypothalamic-Pituitary-Adrenocortical (HPA) system dysregulation plays a role in the pathophysiology of depression. However which psychiatric symptoms are related to HPA system dysregulation has not been studied well. The primary aim of this study was to investigate which symptom components of the Hamilton Depression Rating Scale (HAM-D) are related to HPA system dysregulation in Korean psychiatric outpatients. The secondary aim was to find other variables that have association with HAM-D components. METHODS: This study was a retrospective review of the charts of outpatients who first visited Samsung Medical Center Depression Clinic between July 2012 and October 2013. Among them those who checked the plasma cortisol level and HAM-D within one week of their first visit were selected. Fifty nine patients were selected. The HAM-D was divided into four components, including depression, anxiety, insomnia, and somatic components. Multiple regression of cortisol level was used for four subscales. RESULTS: Significant positive correlations were observed between the plasma cortisol level and depression component of HAM-D (beta=0.251, p=0.049). Age also showed negative correlation with the depression component of HAM-D (beta=-0.427, p=0.002). However anxiety, insomnia and somatic components of HAM-D did not show correlation with plasma cortisol level. CONCLUSION: Our study suggests that in Korean depression clinic outpatients, the depression component of HAM-D is related to plasma cortisol level.

The Usefulness of the Korean Version of Penn State Worry Questionnaire for Screening Generalized Anxiety Disorder: A Receiver Operating Characteristic Analysis

OBJECTIVE: Excessive worry about minor matters and a state in which this worry is experienced as uncontrollable are known to be key symptoms of generalized anxiety disorder (GAD). Given the importance of pathological worry in GAD, the need for psychometrically sound measures of this construct has increased. The purpose of this study was to investigate the usefulness of the Korean version of Penn State Worry Questionnaire (K-PSWQ) for screening GAD. METHODS: Two hundred and forty six patients were initially screened, from which 102 GAD patients and 118 patients with anxiety disorder not otherwise specified (anxiety disorder NOS) were finally enrolled. Patients were diagnosed by a structured clinical interview for the DSM-IV Axis I. We also enrolled 114 control subjects who had no medical or psychiatric history. Pathological worry in both patients and control subjects were assessed at baseline using the PSWQ and we estimated optimal cutoff score by the receiver operating characteristic (ROC) analysis. RESULTS: We found that in the first ROC analysis, a score of 53 could simultaneously optimize sensitivity and specificity in order to discriminate GAD patients from control subjects. From the second receiver operating characteristic analysis, when both sensitivity and specificity were optimized, we can suggest a score of 61 as being the cutoff for differentiating GAD patients from patients with anxiety disorder NOS. CONCLUSION: The Korean version of PSWQ is a useful method for screening GAD patients, although ethnic and cultural differences may affect the cutoff score of PSWQ for GAD.

Clinical Characteristics of the Respiratory Subtype in Panic Disorder Patients

OBJECTIVE: Panic disorder has been suggested to be divided into the respiratory and non-respiratory subtypes in terms of its clinical presentations. The present study aimed to investigate whether there are any differences in treatment response and clinical characteristics between the respiratory and non-respiratory subtypes of panic disorder patients. METHODS: Among the 48 patients those who completed the study, 25 panic disorder patients were classified as the respiratory subtype, whereas 23 panic disorder patients were classified as the non-respiratory subtype. All patients were treated with escitalopram or paroxetine for 12 weeks. We measured clinical and psychological characteristics before and after pharmacotherapy using the Panic Disorder Severity Scale (PDSS), Albany Panic and Phobic Questionnaire (APPQ), Anxiety Sensitivity Index-Revised (ASI-R), State-Trait Anxiety Inventory (STAI-T, STAI-S), Hamilton Anxiety Rating Scale (HAM-A), and Hamilton Depression Rating Scale (HAM-D). RESULTS: The prevalence of the agoraphobia was significantly higher in the respiratory group than the non-respiratory group although there were no differences in gender and medication between the two groups. The respiratory group showed higher scores on the fear of respiratory symptoms of the ASI-R. In addition, after pharmacotherapy, the respiratory group showed more improvement in panic symptoms than the non-respiratory group. CONCLUSION: Panic disorder patients with the respiratory subtype showed more severe clinical presentations, but a greater treatment response to SSRIs than those with non-respiratory subtype. Thus, classification of panic disorder patients as respiratory and non-respiratory subtypes may be useful to predict clinical course and treatment response to SSRIs.

Temperament Affects Sympathetic Nervous Function in a Normal Population

OBJECTIVE: Although specific temperaments have been known to be related to autonomic nervous function in some psychiatric disorders, there are few studies that have examined the relationship between temperaments and autonomic nervous function in a normal population. In this study, we examined the effect of temperament on the sympathetic nervous function in a normal population. METHODS: Sixty eight healthy subjects participated in the present study. Temperament was assessed using the Korean version of the Cloninger Temperament and Character Inventory (TCI). Autonomic nervous function was determined by measuring skin temperature in a resting state, which was recorded for 5 minutes from the palmar surface of the left 5th digit using a thermistor secured with a Velcro(R) band. Pearson's correlation analysis and multiple linear regression were used to examine the relationship between temperament and skin temperature. RESULTS: A higher harm avoidance score was correlated with a lower skin temperature (i.e. an increased sympathetic tone; r=-0.343, p=0.004) whereas a higher persistence score was correlated with a higher skin temperature (r=0.433, p=0.001). Hierarchical linear regression analysis revealed that harm avoidance was able to predict the variance of skin temperature independently, with a variance of 7.1% after controlling for sex, blood pressure and state anxiety and persistence was the factor predicting the variance of skin temperature with a variance of 5.0%. CONCLUSION: These results suggest that high harm avoidance is related to an increased sympathetic nervous function whereas high persistence is related to decreased sympathetic nervous function in a normal population.

Efficacy and Safety of Paliperidone Extended Release in Schizophrenia Patients Requiring a Switch in Antipsychotic Medication by Switching Previous Antipsychotics to Paliperidone Extended Release / 대한정신약물학회지

OBJECTIVE: This study aimed to evaluate the clinical efficacy, safety, and tolerability of paliperidone extended release (ER) in patients with schizophrenia by switching previous antipsychotics to paliperidone ER. METHODS: An open-label, 24 weeks, prospective, non-comparative, multi-center study evaluated total 387 patients with schizophrenia requiring a switch in antipsychotic medication due to suboptimal efficacy, intolerability, and non-compliance. Patients were switched to flexible-dose trial of paliperidone ER (3-12 mg/day). Efficacy was measured by Krawiecka Scale, Clinical Global Impression-Schizophrenia-Severity (CGI-SCH-S), Clinical Global Impression-Schizophrenia-Improvement (CGI-SCH-I), sleep visual analog scale (VAS), and Personal and Social Performance Scale (PSP). Safety assessments included adverse events (AEs), evaluation of extrapyramidal symptoms (EPS) using the Drug Induced Extrapyramidal Symptoms Scale (DIEPSS), and laboratory tests. RESULTS: Data from a total of 321 subjects who took the paliperidone ER and had at least one follow-up assessment without a major protocol violation were analyzed. Switching to paliperidone ER led to a significant improvement in the Krawiecka, CGI-SCH-S, CGI-SCH-I, PSP, and DIEPSS scales. However, serum prolactin levels and metabolic parameters including body weight and waist circumference were significantly increased. Insomnia was the most common adverse event. CONCLUSION: This study suggested that patients with schizophrenia who showed insufficient response or intolerance to other previous antipsychotics can be switched to paliperidone ER, with efficacy, safety, and tolerability.

A Study on Reliability and Validity of the Nurses' Global Assessment of Suicide Risk (NGASR) for Psychiatric Inpatients / 정신간호학회지

PURPOSE: Assessment of suicide risk is a critical task for nurses, especially for nurses working with psychiatric inpatients. The purpose of this study was to verify the reliability and validity of the Nurses' Global Assessment of Suicide Risk (NGASR) for psychiatric inpatients. METHODS: This study was methodological study. A scale composed of 15 items was used with 106 psychiatric inpatients in open and closed psychiatric units of a tertiary hospital. Cohen's kappa coefficient, Intraclass correlation, factor analysis and Jonckheere-Terpstra Test for Ordered Alternatives were used for statistic analysis. RESULTS: Main results were as follows; Reliability of the scale was supported with a total intraclass correlation coefficient of .890 (range from .722 to 1.000). In investigating construct validity, 15 items loaded on six factors which explained 63.4% of total variance. Also the Jonckheere-Terpstra test revealed a significant trend in the order of median scores of NGASR across the three groups of Evaluation of Suicide Risk (ESR). These results supported the criterion-related validity of the scale. CONCLUSION: The findings in this study indicate that this scale is reliable and valid in assessing suicide risk of psychiatric inpatients. Therefore it is an appropriate scale to assess suicide risk for psychiatric inpatients.

Long-term Escitalopram Treatment in Korean Patients with Panic Disorder: A Prospective, Naturalistic, Open-label, Multicenter Trial

OBJECTIVE: Panic disorder is characterized by recurrent panic attacks, persistent concerns about additional attacks, and worry about the implications of the attack or significant changes in behavior related to the attacks. We examined the efficacy of 24-week naturalistic, open-label escitalopram treatment in terms of the response and remission rates and functional disability in 119 adult Korean patients with panic disorder from 6 clinical centers in South Korea. METHODS: Clinical severity and functional impairment were assessed at baseline and at 4, 12, and 24 weeks after the treatment using the Panic Disorder Severity Scale and Sheehan Disability Scale. Ninety-six patients (80.7%) showed a treatment response, and 87 patients (73.1%) had attained remission after 24 weeks of escitalopram treatment. RESULTS: Continuous improvement in the Panic Disorder Severity Scale and Sheehan Disability Scale scores was found over the 24 weeks of treatment. CONCLUSION: These findings suggest that escitalopram treatment is very effective for panic disorder in terms of both response and remission rates and that long-term pharmacotherapy with escitalopram continuously improved panic symptoms and functional disability in Korean patients with panic disorder.

Uncontrolled Self-Medication with Venlafaxine in a Patient with Major Depressive Disorder

Antidepressants are known to have no significant ability to cause addiction. However, a recent study showed many individuals with mood disorders self-medicated with antidepressants to relieve symptoms. We report here a male physician, diagnosed five years ago with major depressive disorder, with insomnia, anxiousness, and chest heaviness. He began self-medicating with 150 mg of venlafaxine daily, without any monitoring. During his most recent severe depressive episode, he was taking up to 1,500 mg of venlafaxine daily. Without this medication, he experienced discontinuation syndrome, which included severe anxiety, chest heaviness, and breathing difficulty, and which he judged as indicating a more severely depressed state. He also experienced overdose symptoms, such as hypertension and tachycardia. He attempted suicide with drugs that he possessed. In conclusion, careful monitoring is needed when treating patients with venlafaxine, because its discontinuation syndrome is similar to symptoms of major depressive disorder, and suicidality may result from an overdose.

The Genetic Basis of Panic Disorder

Panic disorder is one of the chronic and disabling anxiety disorders. There has been evidence for either genetic heterogeneity or complex inheritance, with environmental factor interactions and multiple single genes, in panic disorder's etiology. Linkage studies have implicated several chromosomal regions, but no research has replicated evidence for major genes involved in panic disorder. Researchers have suggested several neurotransmitter systems are related to panic disorder. However, to date no candidate gene association studies have established specific loci. Recently, researchers have emphasized genome-wide association studies. Results of two genome-wide association studies on panic disorder failed to show significant associations. Evidence exists for differences regarding gender and ethnicity in panic disorder. Increasing evidence suggests genes underlying panic disorder overlap, transcending current diagnostic boundaries. In addition, an anxious temperament and anxiety-related personality traits may represent intermediate phenotypes that predispose to panic disorder. Future research should focus on broad phenotypes, defined by comorbidity or intermediate phenotypes. Genome-wide association studies in large samples, studies of gene-gene and gene-environment interactions, and pharmacogenetic studies are needed.

Productivity Time Lost by Sleep Disturbance among Workers in Korea / 신경정신의학

OBJECTIVES: The daily activities and performance of the working population can be threatened by sleep disturbances, including insomnia. This study evaluated the sleep patterns, sleep problems, daytime sleepiness, and lost productivity time (LPT) resulting from sleep quality and sleep duration issues among workers. METHODS: The Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), and the Health and Work Performance Questionnaire (HPQ) were completed by 653 workers in an urban area. Statistical analyses were performed using independent t-tests. RESULTS: The average sleep duration among the subjects was 6 h 37 min. While 19.6% of the subjects complained of poor sleep quality, 53.4% were affected during the day by insomnia. The estimated annual cost of LPT due to presenteeism (Won13,892,545 vs. Won11,840,140 ; p=0.033) and the total annual cost of LPT (Won14,040,968 vs. Won11,961,302 ; p=0.032) were higher in poor sleepers than in good sleepers. Furthermore, workers with a shorter sleep duration had a higher annual LPT due to presenteeism (747.83 vs. 648.57 h ; p=0.046) and a higher total annual LPT (754.48 vs. 657.99 h ; p=0.049) than workers with a longer sleep duration. CONCLUSION: Sleep deprivation among workers caused 1 h 51 min LPT per week. This suggests that sleep disturbance affects workers' performance in an organization, as well as in terms of individual health.

Productivity Time Lost by Sleep Disturbance among Workers in Korea / 신경정신의학

OBJECTIVES: The daily activities and performance of the working population can be threatened by sleep disturbances, including insomnia. This study evaluated the sleep patterns, sleep problems, daytime sleepiness, and lost productivity time (LPT) resulting from sleep quality and sleep duration issues among workers. METHODS: The Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), and the Health and Work Performance Questionnaire (HPQ) were completed by 653 workers in an urban area. Statistical analyses were performed using independent t-tests. RESULTS: The average sleep duration among the subjects was 6 h 37 min. While 19.6% of the subjects complained of poor sleep quality, 53.4% were affected during the day by insomnia. The estimated annual cost of LPT due to presenteeism (Won13,892,545 vs. Won11,840,140 ; p=0.033) and the total annual cost of LPT (Won14,040,968 vs. Won11,961,302 ; p=0.032) were higher in poor sleepers than in good sleepers. Furthermore, workers with a shorter sleep duration had a higher annual LPT due to presenteeism (747.83 vs. 648.57 h ; p=0.046) and a higher total annual LPT (754.48 vs. 657.99 h ; p=0.049) than workers with a longer sleep duration. CONCLUSION: Sleep deprivation among workers caused 1 h 51 min LPT per week. This suggests that sleep disturbance affects workers' performance in an organization, as well as in terms of individual health.

Relationship between Personality and Insomnia in Panic Disorder Patients

OBJECTIVE: Panic disorder (PD) is frequently comorbid with insomnia, which could exacerbate panic symptoms and contribute to PD relapse. Research has suggested that characteristics are implicated in both PD and insomnia. However, there are no reports examining whether temperament and character affect insomnia in PD. Thus, we examined the relationship between insomnia and personality characteristics in PD patients. METHODS: Participants were 101 patients, recruited from 6 university hospitals in Korea, who met the DSM-IV-TR criteria for PD. We assessed sleep outcomes using the sleep items of 17-item Hamilton Depression Rating Scale (HAMD-17)(item 4=onset latency, item 5=middle awakening, and item 6=early awakening) and used the Cloninger's Temperament and Character Inventory-Revised-Short to assess personality characteristics. To examine the relationship between personality and insomnia, we used analysis of variance with age, sex, and severity of depression (total HAMD scores minus sum of the three sleep items) as the covariates. RESULTS: There were no statistical differences (p>0.1) in demographic and clinical data between patients with and without insomnia. Initial insomnia (delayed sleep onset) correlated to a high score on the temperamental dimension of novelty seeking 3 (NS3)(F1,96=6.93, p=0.03). There were no statistical differences (p>0.1) in NS3 between patients with and without middle or terminal insomnia. CONCLUSION: The present study suggests that higher NS3 is related to the development of initial insomnia in PD and that temperament and character should be considered when assessing sleep problems in PD patients.

The Positive and Negative Affect Schedule: Psychometric Properties of the Korean Version

OBJECTIVE: The Positive and Negative Affect Schedule (PANAS) was developed as a measure of positive affect (PA) and negative affect (NA). The aim here is to examine the factor structure and concurrent validity of the Korean version of the Positive and Negative Affect Schedule (K-PANAS) in a clinical sample in Korea. METHODS: K-PANAS was administered to a clinical sample in Korea. Internal consistency, test-retest reliability, and confirmatory factor analysis (CFA) were undertaken to examine the factorial structure and reliability of the K-PANAS. RESULTS: The reliability of K-PANAS is satisfactory. CFA showed that several of the models commonly used in Western populations provided an insufficient fit. The modified model provided a more adequate fit to the data. CONCLUSION: The authors demonstrate that the K-PANAS has adequate psychometric properties, and that findings obtained in the West using PANAS were partially replicated.

Changes in Cerebral Cortex and Limbic Brain Functions after Short-Term Paroxetine Treatment in Panic Disorder: An 18FFDG-PET Pilot Study

OBJECTIVE: Panic disorder (PD) is a common and often chronic psychiatric illness, and serotonin-specific reuptake inhibitors (SSRIs) are the drugs of choice for the treatment of PD. Previous studies suggested the cerebral cortex and limbic brain structures played a major role in the development of PD, but the therapeutic effect of SSRIs on specific brain structures remains unclear in PD. We examined the changes in PD patients' glucose metabolism using the [18F] Fluorodeoxy-glucose-positron emission tomography (FDG-PET) before and after 12 weeks of paroxetine treatment. METHODS: We assessed the brain glucose metabolism of 5 PD patients, using the [18F]FDG-PET, and treated them with paroxetine (12.5-37.5 mg/day) for 12 weeks. Then, we compared before and after treatment PET images of the patients, using voxel-based statistical analysis and a post hoc regions of interest analysis. Furthermore, we measured the patients' clinical variables, including information from the Panic Disorder Severity Scale (PDSS), Clinical Global Impression for Severity (CGI-S), and Hamilton Anxiety Rating Scale (HAMA). RESULTS: After 12 weeks of paroxetine treatment, the patients showed significant clinical improvement in terms of PDSS, CGI-S and HAMA scores (12.8+/-1.8 vs. 3.8+/-2.3, 4.6+/-0.5 vs. 2.0+/-1.4, and 15.2+/-4.0 vs. 5.0+/-1.2, respectively; all p values<0.05). After treatment, patients' glucose metabolism increased significantly in global brain areas: the right precentral gyrus, right middle frontal gyrus, right amygdala, right caudate body, right putamen, left middle frontal gyrus, left precentral gyrus, left insula, left parahippocampal gyrus, and left inferior frontal gyrus (All areas were significant at uncorrected p<0.001 and cluster level corrected p<0.05). CONCLUSION: In these PD patients, cerebral cortex and limbic brain functions changed after short-term treatment with paroxetine. The therapeutic action of paroxetine may be related to altered glucose metabolism at both the cerebral cortex and limbic brain areas.

Korean Medication Algorithm Project for Generalized Anxiety Disorder 2009 (I) : Initial Treatment Strategy / 신경정신의학

OBJECTIVES: This study investigated the consensus about treatment strategies for the initial treatment of generalized anxiety disorder (GAD). This issue represents one of the subjects addressed by the Korean Medication Algorithm Project for GAD in Korea. METHODS: The executive committee of the Korean Medication Algorithm Project for GAD, supported by The Korean Association of Anxiety Disorders, developed questionnaires about treatment strategies for patients with GAD, based on guidelines or algorithms and clinical trial studies previously published in foreign countries, especially by the International Psychopharmacology Algorithm Project, the National Institute for Clinical Excellence, and the Canadian Psychiatric Association. Fifty-five (64%) of 86 experts on a committee reviewing GAD in Korea responded to the questionnaires. We classified the consensus of expert opinions into three categories (first-line, second-line, and third-line treatment strategies) and identified the treatment of choice according using a Chi-square test and a 95% confidence interval. RESULTS: For the initial treatment of GAD, antidepressant monotherapy and the combination of antidepressants and benzodiazepines as anxiolytics were recommended as the first line strategies. Escitalopram, paroxetine CR and venlafaxine XR were selected as first-line antidepressant treatments, and alprazolam, clonazepam and lorazepam were the preferred benzodiazepines. The mean starting doses and mean maximum doses of the drugs were 7.55+/-3.09 mg and 24.91+/-8.14 mg for escitalopram, 12.57+/-2.83 mg and 44.76+/-15.00 mg for paroxetine CR, and 46.81+/-16.74 mg and 223.32+/-60.64 mg for venlafaxine XR. CONCLUSION: These results, which reflect recent studies and clinical experiences, may provide guidelines for the initial.

Korean Medication Algorithm Project for Generalized Anxiety Disorder 2009 (II) : Medication Algorithm & Long-Term Medication Treatment Strategy / 신경정신의학

OBJECTIVES: This study was performed to investigate the consensus about medication algorithms, including long-term medication treatment strategies, in the treatment of generalized anxiety disorder (GAD). METHODS: The executive committee of the Korean Medication Algorithm Project for GAD developed questionnaires about the psychopharmacologic treatment strategies for patients with GAD. Fifty-five (65%) of 84 experts of a reviewing committee answered the questionnaires. The consensus of expert opinion was classified into three categories, and the treatments of choice were selected by use of 95% confidence intervals and chi-square-tests. RESULTS: The consensus on the first-line treatment strategy for GAD was as follows. Step 1 is the use of the one of a selective serotonin reuptake inhibitor (SSRI), a serotonin and noradrenaline reuptake inhibitor (SNRI) and buspirone for at least four to six weeks. Step 2 is to switch from a SSRI to a SNRI or buspirone or vice versa. Step 3 is to augment medication with an atypical antipsychotic or add a benzodiazepine or antihistamine. Step 4 is to switch to another combination, which includes a SSRI, a SNRI, mirtazapine or a tricyclic antidepressant Step 6 is to review the diagnosis, and 'benzodiazepines including clonazepam and alprazolam can be combined with another drug even from the initial period'. In terms of long-term medication treatment, the consensus first-line tr-eatment strategy involved the use of venlafaxine XR, escitalopram, fluoxetine, paroxetine CR, sertraline and buspirone. CONCLUSION: This study provided information about the consensus among Korean experts regarding medication algorithms, including long-term medication treatment strategies, in the treatment of GAD.

Korean Medication Algorithm Project for Generalized Anxiety Disorder 2009 (III) : Treatment Strategy for Comorbid Conditions / 신경정신의학

OBJECTIVES: This study investigated the consensus about treatment strategies for comorbid conditions in generalized anxiety disorder (GAD). METHODS: The executive committee of the Korean Medication Algorithm Project for GAD developed questionnaires about treatment strategies for patients with panic disorder based on guidelines or algorithms and clinical trial studies previously published in foreign countries. This study analyzed the treatment strategies for comorbid conditions in GAD. Fifty-five (65%) of 84 experts on a committee reviewing GADs responded to the questionnaires. We classified the consensus of expert opinions into three categories (first-line, second-line, and third-line treatment strategies) and identified the treatment of choice according using a chi2 test and 95% confidence interval. RESULTS: The consensus about treatment strategies in the case of GAD with comorbid depression recommended a selective serotonin reuptake inhibitor (SSRI) and a serotonin norepinephrine reuptake inhibitor (SNRI) as the first-line drug treatment. An SSRI, an SNRI and a benzodiazepine (e.g. alprazolam, clonazepam) are recommended in GAD patients with other comorbid anxiety disorders. CONCLUSION: This study provided information about the consensus among Korean experts with regard to treatment strategies for comorbid conditions of GAD.

Effect of Temperament and Character on Pharmacotherapy in Panic Disorder Patients / 대한정신약물학회지

OBJECTIVE: Temperament and character that represent personality trait are supposed to relate to panic disorder (PD). There are several studies that report a significant relationship among temperament, character and treatment outcome in PD. In this study, we examined whether temperament and character affect the long term outcome of escitalopram treatment in patients with PD. METHODS: Ninety-two patients with PD were recruited at the psychiatric outpatient clinics of 6 university hospitals in South Korea. All patients were treated with escitalopram for 6 months. The Temperament-Character Inventory-Revised-Short (TCI-RS) was administered to all patients at baseline. They were also assessed with the Panic Disorder Severity Scale (PDSS), Hamilton Rating Scale for Anxiety (HAM-A), 17-item Hamilton Rating Scale for Depression (HAMD-17), and Clinical Global Impression on-Severity (CGI-S) at both baseline and after 6 months of pharmacotherapy. RESULTS: There was a significant relationship between reward dependence (RD) and a remission rate in PD patients who were treated with escitalopram, and panic patients who had high RD showed a low remission rate after the treatment. CONCLUSION: This study suggests that high RD predicts a poor treatment response in patients with PD.

Platelet Serotonin Transporter Function and Heart Rate Variability in Patients with Panic Disorder

Many studies showed abnormal serotonin transporter (5-HTT) function and heart rate variability (HRV) in panic disorder patients. The present study investigated the relationship between HRV power spectral analysis findings and platelet serotonin uptake in panic disorder patients. Short-term HRV over 5 min and platelet serotonin transporter uptake parameters (V(max) and K(m)) were measured both in 45 patients with panic disorder and in 30 age-matched normal healthy control subjects. Low frequency power (LF) normalized unit (nu) and LF/high frequency power (HF) were significantly higher, whereas HF and HF nu were lower in the patient group than in the control group. V(max) and K(m) were all significantly lower (i.e., reflects decreased 5-HTT function) in patients with panic disorder than in normal controls. In the patient group, Km was negatively correlated with LF/HF and LF nu whereas no such correlations between them were found in the control group. By multivariate analysis based on multiple hierarchical linear regression, a low Km independently predicted an increased LF nu even after controlling for age, sex, and body mass index in the patient group. These results suggest that impaired 5-HTT function is closely related to dysregulation of autonomic nervous system in panic disorder.

Human Physiological Models of Insomnia / 수면정신생리

Relatively little is known about the neurobiology of insomnia, despite its wide prevalence and broad medical impact. Although much is still to be learned about the pathophysiology of the disorder, identification, systematic assessment, and appropriate treatment are clearly beneficial to patients. Recent research, using quantitative EEG, polysomnography (PSG), multiple sleep latency test (MSLT) and neuroimaging techniques, suggests that some broad areas can be identified as possible pathophysiological models. Sleep-wake homeostat model hypothesizes a failure in homeostatic regulation of sleep, an attenuated increase in sleep drive with time awake, and/or defective sensing of sleep need. Circadian clock model hypothesizes a dysfunctional circadian clock, resulting in changes in the timing of sleep-wake propensity that are incompatible with normal sleep. Intrinsic sleep-wake state mechanism model suggests that abnormal function of insomnia comprises the systems responsible for expression of the sleep states themselves. Extrinsic over-ride mechanism (stress-response) model suggests that insomnia reflects the consequences of overactivity of one of the systems considered "extrinsic" to normal sleep-wake control. Many current therapies for insomnia are based on these physiological models. Several attempts have been made to create a physiological model that would explain this disorder and could be used as a foundation for treatment. However, it appeared that no model can fully explain and clarify all aspects of insomnia. Future research should be necessary to expand our knowledge on the biological dimensions of insomnia.