Mediation model of comorbid anxiety disorders in late-life depression.

BACKGROUND: A number of studies have been conducted on risk factors of comorbid anxiety disorders regarding late-life depression (LLD). This study investigated the associated factors and their relationship to comorbid anxiety disorders in LLD. METHODS: Participants included 190 elderly Thais (73.2% female, with a mean age of 68.39 ± 6.74 years) with depressive disorders, diagnosed according to DSM-IV Diagnosis Axis I disorders assessed by Mini-International Neuropsychiatric Interview. Demographic data, medical and psychiatric history, family psychiatric history, past depression, family history of depression, Neuroticism Inventory and 7-Item Hamilton Depression Rating Scale (HAMD-7) were analyzed for path analysis using Structural Equation Model framework. The bootstrapping method was used for testing indirect effects. RESULTS: Being female was associated with comorbid anxiety disorders with an indirect effect (ß = - 0.032, P = 0.018) through neuroticism, depression severity, history and family history of depression. Family history of depression had no effect on comorbidity (P = 0.090). Neuroticism had an indirect effect on comorbid anxiety disorders (ß = 0.075, P = 0.019) via depression severity as reflected by HAMD-7 score (ß = 0.412, P = < 0.001). Total variance explained from this model was 11%. This model had good-fit index with Chi-square > 0.05, CFI and TLI > 0.95 and RMSEA < 0.06. CONCLUSION: Neuroticism mediates the effect of relationship between sex, family history and history of depressive disorders and comorbid anxiety disorders in LLD. Moreover, depression severity is a mediator for neuroticism and comorbid anxiety disorders. Longitudinal studies are warranted to indicate the importance of effective treatment of depression to lower the risk of developing comorbid anxiety disorders among depressed elderly.

Core Symptom Index (CSI): testing for bifactor model and differential item functioning.

OBJECTIVES: The Core Symptom Index (CSI) is designed to measure anxiety, depression and somatization symptoms. This study examined the construct validity of CSI using confirmatory factor analysis (CFA) including a bifactor model and explored differential item functioning (DIF) of the CSI. The criterion and concurrent validity were evaluated. METHODS: In all, 803 elderly patients, average age 69.24 years, 70% female, were assessed for depressive disorders and completed the CSI and the geriatric depression scale (GDS). A series involving CFA for ordinal scale was applied. Factor loadings and explained common variance were analyzed for general and specific factors; and Omega was calculated for model-based reliability. DIF was analyzed using the Multiple-Indicator Multiple-Cause model. Pearson's correlation, ANOVA, and ROC analysis were used for associations and to compare CSI and GDS in predicting major depressive disorders (MDD). RESULTS: The bifactor model provided the best fit to the data. Most items loaded on general rather than specific factors. The explained common variance was acceptable, while Omega hierarchical for the subscale and explained common variance for the subscales were low. Two DIF items were identified; 'crying' for sex items and 'self-blaming' for education items. Correlation among CSI and clinical disorders and the GDS were found. AUC for the GDS was 0.83, and for the CSI was 0.81. CONCLUSION: CSI appears sufficiently unidimensional. Its total score reflected a single general factor, permitting users to interpret the total score as a sufficient reliable measure of the general factors. CSI could serve as a screening tool for MDD.

Prevalence and associated factors of comorbid anxiety disorders in late-life depression: findings from geriatric tertiary outpatient settings.

PURPOSE: The study evaluated the prevalence of comorbid anxiety disorders in late-life depression (LLD) and identified their associated factors. PATIENTS AND METHODS: This study involved 190 elderly Thais with depressive disorders diagnosed according to the Mini-International Neuropsychiatric Interview (MINI). Anxiety disorders were also diagnosed by the MINI. The 7-item Hamilton Depression Rating Scale (HAMD-7), Montreal Cognitive Assessment, Geriatric Depression Scale (GDS), Core Symptoms Index, Neuroticism Inventory, Perceived Stress Scale and Multidimensional Scale for Perceived Social Support were completed. Descriptive statistics and ORs were used for analysis. RESULTS: Participants included 139 females (73.2%) with a mean age of 68.39±6.74 years. The prevalence of anxiety disorders was 7.4% for generalized anxiety disorder (GAD), 4.7% for panic disorder, 5.3% for agoraphobia, 1.1% for social phobia, 2.1% for obsessive-compulsive disorder and 3.7% for post-traumatic stress disorder, with an overall prevalence of 16.84%. The comorbidity of anxiety disorders was associated with gender (P=0.045), history of depressive disorder (P=0.040), family history of depressive disorder (P=0.004), GDS (P=0.037), HAMD-7 (P=0.001), suicidality (P=0.002) and neuroticism (P=0.003). History of alcohol use was not associated. CONCLUSION: The prevalence of anxiety in LLD was comparable to other studies, with GAD and agoraphobia being the most prevalent. This study confirmed the role of depression severity and neuroticism in developing comorbid anxiety disorders.

Prevalence, clinical and psychosocial variables of depression, anxiety and suicidality in geriatric tertiary care settings.

OBJECTIVE: The study investigated the prevalence of depressive and anxiety disorders and suicide risk in geriatric outpatients in tertiary care hospitals. MATERIALS AND METHODS: An observational, cross-sectional study was conducted with 803 participants aged 60 and above attending geriatric outpatient clinics in tertiary care hospitals in Thailand. Participants were assessed using DSM-IV-TR criteria to calculate the prevalence of deressive and anxiety disorders, and their suicide risk. Montreal Cognitive Assessment (MoCA), Perceived Stress Scale (PSS), Multidimensional Scale of Perceived Social Support, Core Symptom Index (CSI), 15-item Geriatric Depression Scale (GDS-15), Neuroticism Inventory (NI) and the Revised Experience of Close Relationships Questionnaire (ECR-R) were administered. Quality of life was assessed using the EuroQoL (EQ-5D). RESULTS: The prevalence rate for depressive disorders was 23.7%, anxiety disorders was 6.4%, and current suicide risk was 20.4%. PSS, MSPSS, GDS, CSI, and NI scores were significantly higher in all clinical disorders and a suicide group compared with nonclinical subjects. MoCA and ECR-R did not differentiate between clinical disorder and nonclinical samples. Comparing all four outcomes, the EQ-5D differed most in the mixed depressive-anxiety disorder and nonclinical groups (t = 12.20, p < .001). CONCLUSION: The present findings revealed a high prevalence of depression, anxiety and suicidality among elderly patients attending tertiary care hospitals. Perceived stress, perceived social support, and neuroticism scores were significantly higher in this group. Role of sociodemographic, clinical and psychosocial variables as risk factors for these clinical disorders should be further examined.

Influence of the UGT2B7 -161C>T polymorphism on the population pharmacokinetics of lamotrigine in Thai patients.

BACKGROUND AND OBJECTIVES: A high inter-individual variability in the pharmacokinetics of lamotrigine has been observed. Lamotrigine is primarily metabolized by UGT1A4 and UGT2B7, both of which show genetic polymorphisms. Both genetic and non-genetic factors may influence the pharmacokinetics of lamotrigine. The aim of this study was to determine the pharmacokinetic parameters of lamotrigine and to investigate the effect of genetic variants of UGT1A4 and UGT2B7 and various non-genetic factors on its pharmacokinetics. METHODS: Four single nucleotide polymorphisms (SNPs; UGT1A4 142 T>G, UGT1A4 70C>T, UGT2B7 372A>G, UGT2B7 -161C>T) were identified using the TaqMan Allelic Discrimination Assay. Data were analyzed using NONMEM. Model evaluation was performed using the bootstrap approach and predictive check. RESULTS: A total of 116 samples were obtained from 75 patients and included in the population analysis. The use of enzyme inducers, valproic acid, and the UGT2B7-161 C>T SNP were found to significantly influence lamotrigine apparent clearance (CL/F). Lamotrigine CL/F in patients carrying the UGT2B7 -161 CT or TT SNP was 18% lower than that in patients carrying the UGT2B7 -161 CC SNP. CONCLUSION: Both genetic and non-genetic factors were found to influence lamotrigine pharmacokinetics. These factors should be considered when determining lamotrigine dosing. The model presented here could be useful for lamotrigine dose adjustment in clinical practice.