Orexin-a elevation in antipsychotic-treated compared to drug-free patients with schizophrenia: A medication effect independent of metabolic syndrome.

BACKGROUND/PURPOSE: Orexin-A levels are reportedly increased in antipsychotic (APD)-treated patients with schizophrenia compared to healthy controls and have been associated with metabolic abnormalities. It is not clear whether the orexin-A elevation is related specifically to the drug (APDs) effect, which should be clarified by including a drug-free group for comparison, or related to drug-induced metabolic abnormalities. METHODS: Blood orexin-A levels and metabolic profiles were compared between 37 drug-free, 45 aripiprazole-treated, and 156 clozapine-treated patients with schizophrenia. The association between orexin-A and metabolic outcomes were examined. We explored the effects of APDs treatment and metabolic status on orexin-A levels by linear regression. RESULTS: Patients under APDs treatment had increased orexin-A levels compared to drug-free patients, with aripiprazole-treated group having higher orexin-A levels than clozapine-treated group. Higher orexin-A levels reduced the risks of metabolic syndrome (MS) and type 2 diabetes mellitus, indicating a relationship between orexin-A levels and metabolic problems. After adjusting the effect from metabolic problems, we found APD treatment is still associated with orexin-A regulation, with aripiprazole more significantly than clozapine. CONCLUSION: With the inclusion of drug-free patients rather than healthy controls for comparison, we demonstrated that orexin-A is upregulated following APD treatment even after we controlled the potential effect from MS, suggesting an independent effect of APDs on orexin-A levels. Furthermore, the effect differed between APDs with dissimilar obesogenicity, i.e. less obesogenicity likely associated with higher orexin-A levels. Future prospective studies exploring the causal relationship between APDs treatment and orexin-A elevation as well as the underlying mechanisms are warranted.

Crosstalk between Schizophrenia and Metabolic Syndrome: The Role of Oxytocinergic Dysfunction.

The high prevalence of metabolic syndrome in persons with schizophrenia has spurred investigational efforts to study the mechanism beneath its pathophysiology. Early psychosis dysfunction is present across multiple organ systems. On this account, schizophrenia may be a multisystem disorder in which one organ system is predominantly affected and where other organ systems are also concurrently involved. Growing evidence of the overlapping neurobiological profiles of metabolic risk factors and psychiatric symptoms, such as an association with cognitive dysfunction, altered autonomic nervous system regulation, desynchrony in the resting-state default mode network, and shared genetic liability, suggest that metabolic syndrome and schizophrenia are connected via common pathways that are central to schizophrenia pathogenesis, which may be underpinned by oxytocin system dysfunction. Oxytocin, a hormone that involves in the mechanisms of food intake and metabolic homeostasis, may partly explain this piece of the puzzle in the mechanism underlying this association. Given its prosocial and anorexigenic properties, oxytocin has been administered intranasally to investigate its therapeutic potential in schizophrenia and obesity. Although the pathophysiology and mechanisms of oxytocinergic dysfunction in metabolic syndrome and schizophrenia are both complex and it is still too early to draw a conclusion upon, oxytocinergic dysfunction may yield a new mechanistic insight into schizophrenia pathogenesis and treatment.

Oxytocin in Schizophrenia: Pathophysiology and Implications for Future Treatment.

Schizophrenia is a form of mental disorder that is behaviorally characterized by abnormal behavior, such as social function deficits or other behaviors that are disconnected from reality. Dysregulation of oxytocin may play a role in regulating the expression of schizophrenia. Given oxytocin's role in social cognition and behavior, a variety of studies have examined the potential clinical benefits of oxytocin in improving the psychopathology of patients with schizophrenia. In this review, we highlight the evidence for the role of endogenous oxytocin in schizophrenia, from animal models to human studies. We further discuss the potential of oxytocin as a therapeutic agent for schizophrenia and its implication in future treatment.

Association of Craving and Depressive Symptoms in Ketamine-Dependent Patients Undergoing Withdrawal Treatment.

BACKGROUND AND OBJECTIVES: Ketamine has emerged as one of the major illicit substances worldwide. Craving, a primary symptom for addiction, is a key challenge for ketamine abusers attempting abstinence. A link between craving and negative affect has been suggested previously for other substances. We examined the relationship between craving and negative effect (depression and anxiety) in patients with ketamine dependence (KD) undergoing withdrawal treatment. METHODS: We included 104 patients with KD (76 males and 28 females) who received inpatient treatment for ketamine withdrawal and assessed them by using Beck Depression Inventory (BDI), Beck Anxiety Inventory, and a visual analog scale (VAS; 0-100 mm) for ketamine craving on day 2 to 3 of admission. RESULTS: Fifty-nine (59%) and 38 (38.7%) of our patients reported moderate-to-severe depression and anxiety symptoms, respectively. Patients with greater cravings (ie, greater than the median VAS) reported spending more days on ketamine in the preceding month and displayed severer depressive symptoms than did those with lower cravings. VAS was significantly correlated with BDI scores after adjustment. Patients who stayed in the treatment longer (more than 2 weeks) experienced more cravings and depressive symptoms than those who did not. DISCUSSION AND CONCLUSIONS: We observed a high prevalence of depression in patients with KD, particularly those with higher cravings. Patients with greater cravings and severer depression might require a longer duration of withdrawal treatment. SCIENTIFIC SIGNIFICANCE: This research provides intimal evidence for an association between depression and craving in patients with KD. Screening and management of depression are recommended for this population. (Am J Addict 2019;00:00-00).

Orexin-A Levels in Relation to the Risk of Metabolic Syndrome in Patients with Schizophrenia Taking Antipsychotics.

Background: The role of orexin-A in regulating metabolic homeostasis has been recognized, but its association with antipsychotic-induced metabolic abnormalities remains unclear. We investigated the association between orexin-A levels and metabolic syndrome in patients with schizophrenia treated with clozapine or less obesogenic antipsychotics compared with nonpsychiatric controls. Methods: Plasma orexin-A levels and metabolic parameters were determined in 159 patients with schizophrenia: 109 taking clozapine; 50 taking aripiprazole, amisulpride, ziprasidone, or haloperidol; and 60 nonpsychiatric controls. Results: Orexin-A levels were significantly higher in the group taking less obesogenic antipsychotics, followed by the clozapine group and the controls (F=104.6, P<.01). Higher orexin-A levels were correlated with better metabolic profiles in the patient groups but not in the controls. Regression analyses revealed that the patients with higher orexin-A levels had significantly lower risk of metabolic syndrome (adjusted odds ratio [OR]=0.04, 95% CI: 0.01-0.38 for the 2nd tertile; OR=0.04, 95% CI: 0.01-0.36 for the 3rd tertile, compared with the first tertile), after adjustment for age, sex, smoking history, types of antipsychotics (clozapine vs less obesogenic antipsychotics), duration of antipsychotic treatment, and disease severity. Conclusions: Our results revealed that the orexin-A level was upregulated in patients with schizophrenia treated with antipsychotics, especially for the group taking less obesogenic antipsychotics. Furthermore, higher orexin-A levels were independently associated with better metabolic profiles. These observations suggest that an upregulation of orexin-A has a protective effect against the development of metabolic abnormalities in patients with schizophrenia receiving antipsychotic treatment.

Homocysteine, rather than age of onset, is a better predictor for cognitive function in older adults with bipolar disorder.

OBJECTIVES: The association between older-age bipolar disorder and cognitive impairments may be mediated by vascular burden. The aim of the study was to examine the difference of cognitive function between older people with late-onset bipolar disorder (LOBD) and early-onset bipolar disorder (EOBD) by considering rigorous vascular risk burden evaluation, comprehensive cognitive tests, and relevant biochemistry data. METHODS: We recruited 95 outpatients aged over 55 with a DSM-IV-TR diagnosis of bipolar I disorder. Fifty had LOBD, defined by age of onset after 40. Cognitive function was evaluated through a battery of tests assessing verbal memory, attention/speed, visuospatial function, verbal fluency, and cognitive flexibility. Vascular risk assessments included individual disorders, 10-year Framingham cardiovascular risk scores, and serum levels of homocysteine, vitamin B12, folate, and triiodothyronine. RESULTS: No differences were observed between LOBD and EOBD on any cognitive test after adjusting for potential confounders. In addition to age and educational years, multiple linear regression analyses indicated significantly negative associations between serum homocysteine levels and cognitive performances in attention, psychomotor speed, verbal memory, and executive function. CONCLUSIONS: Among older people with bipolar disorder, LOBD is not associated with more cognitive dysfunction in this study. However, higher serum homocysteine levels were significantly associated with worse cognitive performance in this particular group. Clinicians therefore have to pay attention to the cognitive function in older bipolar patients with higher levels of homocysteine.

Topiramate mitigates weight gain in antipsychotic-treated patients with schizophrenia: meta-analysis of randomised controlled trials.

OBJECTIVE: Weight gain is one of the most challenging issues in patients with schizophrenia treated with antipsychotics. Several meta-analyses have been conducted to review the efficacy of topiramate in reducing weight, however, several issues regarding the methodology had arisen of which make the results remain ambiguous. METHODS: We conducted a meta-analysis of randomised controlled trials about the use of topiramate in patients with schizophrenia for weight reduction. Ten double-blinded randomised placebo-controlled trials and seven open-label randomised controlled trials included 905 patients. RESULTS: Patients treated with topiramate experienced a greater reduction in body weight and BMI. Patients in countries of the lower overweight population showed more significant BMI reduction. Besides, studies from the Middle East and South Asia showed the greatest effect in body weight change, followed by East Asia, then Europe/America. Topiramate group was outperformed control group with significant psychopathology improvement. No difference between two groups regarding the overall side effects. CONCLUSIONS: Topiramate was significantly superior to control group in mitigating weight gain and psychopathology in antipsychotic-treated patients with schizophrenia. The effects of topiramate augmentation need further investigations in larger definitive studies using methodological rigor and thorough assessments.

Delirium Phenotype by Age and Sex in a Pooled Data Set of Adult Patients.

The authors aimed to evaluate whether the clinical phenotype of delirium differs if dichotomized either by sex or age (cutoff age, 65 years old) in a pooled sample of 406 nondemented adult patients with delirium as defined by DSM-IV criteria. Delirium characteristics were measured with the Delirium Rating Scale-Revised-98 (DRS-R-98). DRS-R-98 items were subgrouped to represent subscores representing the three core domains of delirium (cognitive, higher-order thinking, and circadian), noncore accessory symptoms (psychotic and affective), and diagnostic characteristics (temporal onset, fluctuation, and physical disorder). The authors compared means of the DRS-R-98 subscores and medians of individual items. Exploratory factor analyses evaluated delirium characteristics for each subgroup for each of the four groups-male, female, nongeriatric, and geriatric-while taking into account active medical diagnoses. Males had higher scores on motor agitation and affective lability (behavioral), whereas females had a higher frequency of hypoactive delirium. Delirium had a two-factor structure that emerged in all four study groups, and all its core domains loaded (i.e., correlated together) onto some of these two factors and with circadian domain correlating with accessory symptoms. Although the influence of a variety of active diagnoses on delirium was small and complex, traumatic brain injury had a clear influence on cognitive domain and abrupt onset. Age had a mild influence over delirium characteristics for both males and females. In conclusion, the authors confirmed a two-factor structure for delirium phenomenology, regardless of age and sex, with few significant differences between etiological groups.

Increased blood 8-hydroxy-2-deoxyguanosine levels in methamphetamine users during early abstinence.

BACKGROUND: Reactive oxygen species (ROS) are thought to play a role in the adverse physical and mental consequences of methamphetamine usage. The oxidative DNA adduct 8-hydroxy-2'-deoxyguanosine (8-OHdG) is a well-known biomarker of ROS-induced DNA damage. Currently, there is insufficient clinical information about methamphetamine-induced oxidative DNA damage. OBJECTIVES: This study examined differences in blood levels of 8-OHdG between methamphetamine users and non-users as well as alterations in 8-OHdG levels after 2 weeks of methamphetamine abstinence. METHODS: We recruited 182 methamphetamine users (78.6% of male) and 71 healthy controls (95.8% of male). Baseline serum 8-OHdG levels were measured in both groups using a competitive enzyme-linked immunosorbent assay. In methamphetamine users, 8-OHdG levels were measured again 2 weeks after baseline measurement. RESULTS: The results showed that methamphetamine users had significantly higher 8-OHdG levels (0.34 ± 0.13 ng/mL) than healthy controls (0.30 ± 0.08 ng/mL) (p < 0.001). The 8-OHdG levels did not alter after 2 weeks of methamphetamine abstinence (0.32 ± 0.12 ng/mL, p = 0.051 compared to baseline measurement; p = 0.12 compared to healthy controls). No significant correlations were observed between baseline 8-OHdG levels in methamphetamine users and post-abstinence interval, age of the first methamphetamine use, duration of methamphetamine use, or history of frequent methamphetamine use. CONCLUSION: Our findings suggest that methamphetamine users had an enhanced level of oxidative damage, which did not normalize during early abstinence. Future studies are required to determine the effects of long-term methamphetamine abstinence and potential confounders on 8-OHdG levels in methamphetamine users.

The Relationships of Obesity-Related Genetic Variants With Metabolic Profiles and Response to Metformin in Clozapine-Treated Patients With Schizophrenia.

Obesity-related genetic variants, including TMEM18 (rs6548238), SH2B1 (rs7498665), and GNPDA2 (rs10938397), have been shown to be associated with obesity in the general population. Our study aimed to test whether these genetic variants are associated with metabolic profiles and metformin treatment response in clozapine-treated schizophrenic patients. We recruited 107 clozapine-treated patients who were genotyped and measured their metabolic profiles. Fifty-five subjects, who had at least 1 metabolic abnormality in a range of measures, were subsequently randomized to a 24-week trial of metformin (n = 28) or placebo (n = 27). We examined the associations between TMEM18, SH2B1, GNPDA2 genetic variants and metabolic profiles at baseline in all patients and metabolic changes in the trial groups. We found a significant association between SH2B1 and blood pressure at baseline in all patients. In the metformin group, TMEM18 minor allele carriers had a greater reduction in insulin levels (P = 0.04). A significantly higher proportion of TMEM18 and GNPDA2 minor allele carriers (60% and 40%) lost more than 7% of their body weight after metformin treatment as compared with their homozygous counterparts (21.7% and 15.4%, P = 0.02 and 0.004, respectively).There were trends toward favorable metabolic changes in minor allele carrier groups. In the placebo group, no association between genetic variants and changes in metabolic profiles was found. In conclusion, the study results suggest that these genes might be associated with metabolic abnormalities and response to metformin in clozapine-treated patients with schizophrenia.

Confirmatory Factor Analysis of the Delirium Rating Scale Revised-98 (DRS-R98).

Principal components analysis applied to the Delirium Rating Scale-Revised-98 contributes to understanding the delirium construct. Using a multisite pooled international delirium database, the authors applied confirmatory factor analysis to Delirium Rating Scale-Revised-98 scores from 859 adult patients evaluated by delirium experts (delirium, N=516; nondelirium, N=343). Confirmatory factor analysis found all diagnostic features and core symptoms (cognitive, language, thought process, sleep-wake cycle, motor retardation), except motor agitation, loaded onto factor 1. Motor agitation loaded onto factor 2 with noncore symptoms (delusions, affective lability, and perceptual disturbances). Factor 1 loading supports delirium as a single construct, but when accompanied by psychosis, motor agitation's role may not be solely as a circadian activity indicator.

Consumption of Alcoholic Energy Drinks Is Associated with Work-related Injury or Disease Among Manual Workers in Taiwan.

AIMS: Alcoholic energy drinks (AEDs) have been popular among Taiwanese manual workers. Study results concerning increased health risks of AED consumption relative to alcohol alone have been inconsistent, and the risk for potential work-related injury or disease has not been studied. Our study goal was to evaluate the association between AED consumption and work-related injury or disease in manual workers in Taiwan. METHODS: National survey data of the working population in 2007 was utilized. A total of 1192 manual workers, who drank alcohol more than once per week, were divided into AED-drinkers and non-AED drinkers. We compared AED drinking behaviors and risk of work-related injury or disease between the two groups. RESULTS: AED drinkers had a higher risk of work-related injury or disease, with an odds ratio of 1.48 (95% CI: 1.14-1.93), after controlling demographic, smoking and drinking characteristics. The presence of problem drinking (defined by CAGE score equal to or higher than two) was another risk factor of having work-related injury or disease. Compared to non-AED counterparts, AED drinkers had a significantly higher prevalence of work-related injury or disease in the strata of CAGE score of 1 and 2. CONCLUSION: AED consumers presented increased risks of work-related injury or disease compared with non-AED drinkers among manual workers in Taiwan. In order to conduct an effective intervention program to protect Taiwanese manual workers from potential risks, the reasons for this increased risk among AED drinkers need to be further studied.

Lack of efficacy of dextromethorphan in managing alcohol withdrawal: a preliminary report of a randomized, double-blind, placebo-controlled trial.

Alcohol withdrawal syndrome is associated with increased central N-methyl-D-aspartate (NMDA) glutamate transmission. Medications that reduce glutamate release or block NMDA overactivation have shown efficacy for treating alcohol withdrawal syndrome. Dextromethorphan (DXM), a widely used antitussive drug, is a low-affinity, noncompetitive NMDA antagonist with potential neuroprotective properties. This study, using a randomized, double-blind, placebo-controlled study design, examined the benefit of DXM in the management of acute alcohol withdrawal. Alcohol-dependent patients admitted for detoxification treatment and experiencing moderate alcohol withdrawal, as measured by a score greater than 10 on the revised Clinical Institute Withdrawal Assessment for Alcohol (CIWA-Ar), were randomly assigned to receive either DXM 360 mg/d or an identical placebo for 7 days in a double-blind manner. All subjects received a concurrent dose of lorazepam 2 mg along with the initial administration of DXM or placebo and were given additional lorazepam (1 mg) as a rescue medication according to the symptom-triggered detoxification protocol. Outcome measures consisted of the mean total dose of lorazepam received, the sequential scores on the CIWA-Ar, and craving assessed by the Obsessive-Compulsive Drinking Scale. Forty subjects completed the study, 18 in the DXM group and 22 in the placebo group. We found that compared with placebo, DXM use was not associated with lower lorazepam doses to control alcohol withdrawal symptoms. The progression in CIWA-Ar and Obsessive-Compulsive Drinking Scale scores was also comparable between the 2 groups. Our preliminary results do not support the efficacy of high-dose DXM in reducing the need of benzodiazepines to treat withdrawal symptoms in alcohol-dependent patients.

Comparison of oxidative DNA damage between alcohol-dependent patients with and without delirium tremens.

BACKGROUND: Chronic and excessive alcohol consumption increases oxidative stress. We previously found that levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage, are elevated in alcohol-dependent patients without delirium tremens (DTs). The aim of this study was to compare serum 8-OHdG levels between alcohol-dependent patients with and without DTs. METHODS: We recruited 16 alcohol-dependent patients with DTs (DTs group) and 58 patients without DTs (non-DTs group). Alcohol withdrawal severity was evaluated using the Chinese version of the revised Clinical Institute Withdrawal Assessment for Alcohol Scale (CIWA-Ar-C) every 8 hours. Serum levels of 8-OHdG and other biological indices were assayed at baseline and after 1 week of detoxification. RESULTS: The mean 8-OHdG level in the DTs group was significantly higher than that in the non-DTs group (0.50 vs. 0.34 ng/ml, p < 0.001). A significant correlation was found between the highest CIWA-Ar-C scores and serum 8-OHdG levels (ß = 0.43, p = 0.001) in the non-DTs group, but not in the DTs group (ß = 0.34, p = 0.19). An area under receiver operating characteristic curve of 0.83 suggests that 8-OHdG levels potentially differentiate patients with DTs from those without DTs. After dividing the patients into quartiles by 8-OHdG level, we found that compared to the patients in the third and fourth quartiles, the patients in the highest quartile had an odds ratio of 24.1 (p < 0.001) to have DTs, while those in the second highest quartile had an odds ratio of 3.5 (p = 0.19). Serum 8-OHdG levels did not significantly change after 1 week of detoxification in either group. CONCLUSIONS: Alcohol-dependent patients with DTs have higher serum 8-OHdG levels than those without DTs, suggesting that higher oxidative stress carries a greater risk of the occurrence of DTs.

Higher orexin-A levels are associated with treatment response to clozapine in patients with schizophrenia: A cross-sectional study.

BACKGROUND: Clozapine is the primary antipsychotic (APD) for treatment-resistant schizophrenia (TRS). However, only 40% of patients with TRS respond to clozapine, constituting a subgroup of clozapine-resistant patients. Recently, the neuropeptide orexin-A was shown to be involved in the pathophysiology of schizophrenia. This study evaluated the association of orexin-A levels with the clozapine response in patients with TRS. METHODS: We recruited 199 patients with schizophrenia, including 37 APD-free and 162 clozapine-treated patients. Clozapine-treated patients were divided into clozapine-responsive (n = 100) and clozapine-resistant (n = 62) groups based on whether they had achieved psychotic remission defined by the 18-item Brief Psychiatric Rating Scale (BPRS-18). We compared blood orexin-A levels among the three groups and performed regression analysis to determine the association of orexin-A level with treatment response in clozapine-treated patients. We also explored the correlation between orexin-A levels and cognitive function, assessed using the CogState Schizophrenia Battery. RESULTS: Clozapine-responsive patients had higher orexin-A levels than clozapine-resistant and APD-free patients. Orexin-A level was the only factor significantly associated with treatment response after adjustment. Orexin-A levels were negatively correlated with BPRS-18 full scale and positive, negative, and general symptoms subscale scores. We also observed a positive correlation between orexin-A levels and verbal memory, visual learning and memory, and working memory function. CONCLUSIONS: This cross-sectional study showed that higher levels of orexin-A are associated with treatment response to clozapine in patients with TRS. Future prospective studies examining changes in orexin-A level following clozapine treatment and the potential benefit of augmenting orexin-A signaling are warranted.

Determining cut-off values and predictors for the Snaith-Hamilton Pleasure Scale: comparison between clinical and school settings.

BACKGROUND: Few previous studies have established Snaith-Hamilton Pleasure Scale (SHAPS) cut-off values using receiver operating characteristic curve analysis and applied these values to compare predictors of anhedonia between clinical and nonclinical groups. AIMS: To determine the optimal cut-off values for the SHAPS and use them to identify predictors of anhedonia in clinical and nonclinical groups in Taiwan. METHOD: This cross-sectional and correlational study used convenience sampling to recruit 160 patients from three hospitals and 412 students from two universities in northern Taiwan. Data analysis included receiver operating characteristic curve, univariate and multivariate analyses. RESULTS: The optimal SHAPS cut-off values were 29.5 and 23.5 for the clinical and nonclinical groups, respectively. Moreover, two-stage analysis revealed that participants in the clinical group who perceived themselves as nondepressed, and participants in the nonclinical group who did not skip classes and whose fathers exhibited higher levels of care and protection were less likely to attain the cut-off values. Conversely, participants in the nonclinical group who reported lower academic satisfaction and were unwilling to seek help from family or friends were more likely to attain the cut-off values. CONCLUSIONS: Our findings highlight the importance of optimal cut-off values in screening for depression risk within clinical and nonclinical groups. Accordingly, the development of comprehensive, individualised programmes to monitor variation trends in SHAPS scores and relevant predictors of anhedonia across different target populations is crucial.

Three core domains of delirium validated using exploratory and confirmatory factor analyses.

OBJECTIVE: To confirm the existence of the proposed three-core symptom domains in delirium by analyzing a dataset of nondemented adults using selected core symptoms as measured by the Delirium Rating Scale-Revised-98 (DRS-R98) scale. METHODS: Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) of proposed delirium core symptoms were conducted in a pooled international dataset of 592 delirious and nondelirious patients using DSM-IV criteria from 14 studies with comparable methodologies. Using DRS-R98 categorization, 445 had either subsyndromal or full delirium and comprised the delirium group. The dataset was divided into three independent random subsamples to perform a stepwise analysis. First we performed EFA in 100 cases to delineate latent factor loadings of DRS-R98 items selected to represent the three-core domains (circadian, higher level thinking, and cognitive). These items were then assessed using CFA-modeling (n = 246) followed by a CFA-validation (n = 246). Reliability and goodness of fit of these two CFA were assessed statistically. RESULTS: DRS-R98 items representing the proposed delirium core symptoms loaded onto one factor in the EFA, supporting their core nature. The two CFA confirmed the nature of this core factor as comprising three core domains where DRS-R98 items each loaded with high values (>0.7) onto their corresponding core domain (circadian, higher level thinking, and cognitive) with good fit and reliability. Attention was DRS-R98 item with the highest loading in CFA, followed by thought process, and then by sleep-wake cycle and motor behavior. CONCLUSIONS: Our EFA and CFA confirm and validate the proposed three-core domains of delirium, where symptoms were highly related to the domain that they were hypothesized to represent. These domains are consistent with delirium being a state of impaired consciousness, and should be considered necessary to assess whether in clinical or research settings.

Oxidative stress status in recently abstinent methamphetamine abusers.

AIM: Methamphetamine (METH) administration is associated with excessive oxidative stress. It is not known whether the systemic oxidative stress indices would alter during early abstinence in METH abusers with positive urine testing for recent METH exposure. METHODS: Sixty-four non-treatment-seeking METH abusers enrolled from a controlled environment and 60 healthy controls participated in the study. Fasting serum malondialdehyde (MDA) levels and anti-oxidant indices, including superoxide dismutase (SOD) and catalase (CAT) activity, and glutathione (GSH) levels, were measured at baseline and 2 weeks after the first measurement. We compared the differences of these oxidative stress indices between METH abusers and controls and examined the changes of the indices 2 weeks after baseline in the METH group. RESULTS: At baseline, the recently abstinent METH abusers had significantly higher MDA levels, lower SOD activity, and higher CAT activity and GSH levels compared to healthy controls. CAT and GSH values were positively correlated with MDA but negatively correlated with SOD. These oxidative stress indices did not significantly correlate with age, smoking amount, Alcohol Use Disorder Identification Test scores, or METH use variables. After 2 more weeks of abstinence, the indices did not alter nor normalize. CONCLUSION: Compared to controls, we found that METH abusers have persistently higher systemic oxidative stress throughout early abstinence. The compromised SOD as well as elevated CAT activity and GSH levels may act together as a compensatory mechanism to counteract excessive oxidative stress induced by METH. Whether the oxidative stress could improve after a longer period of abstinence needs to be examined in future studies.

Comorbidity of ketamine dependence with major depressive disorder increases the vulnerability to neuroaxonal pathology.

We recently demonstrated that patients with ketamine dependence (KD) have increased serum levels of neurofilament light chain (NfL), a novel marker of active neuroaxonal pathology, with NfL levels being significantly higher in those KD patients comorbid with major depressive disorder (MDD). However, considering that NfL elevation has been associated with both ketamine-related brain pathology and MDD, we could not determine whether the observed elevation of NfL levels was driven by an interaction of KD with MDD or by MDD itself. Therefore, we compared serum NfL levels between 35 patients with MDD without ketamine use (MDD group), 23 with KD without MDD (KD without MDD group), 30 KD with MDD (KD with MDD group), and 86 healthy controls (HC group). Using a 2*2 (KD*MDD) generalized linear model controlling for age, sex, body mass index, and smoking status, we found that KD and KD*MDD interactions, but not MDD factor, significantly affected NfL levels. Posthoc tests showed that the KD with MDD group had significantly higher NfL levels than all other groups. The KD without MDD group also showed higher NfL levels than the MDD and, as shown before, HC groups. The levels in MDD group were not different from the HC group. These results suggest that the interaction of KD with MDD, but not MDD alone, results in increased vulnerability to neuroaxonal pathology.