Serum proteomics analysis of drug-naïve patients with generalised anxiety disorder: Tandem mass tags and multiple reaction monitoring

OBJECTIVES

The prevalence of generalised anxiety disorder (GAD) is high. However, the underlying mechanisms remain elusive. Proteomics techniques can be employed to assess the pathological mechanisms involved in GAD.

METHODS

Twenty-two drug-naive GAD patients were recruited, their serum samples were used for protein quantification and identified using Tandem Mass Tag and Multiple Reaction Monitoring (MRM). Machine learning models were employed to construct predictive models for disease occurrence by using clinical scores and target proteins as input variables.

RESULTS

A total of 991 proteins were differentially expressed between GAD and healthy participants. Gene Ontology analysis revealed that these proteins were significantly associated with stress response and biological regulation, suggesting a significant implication in anxiety disorders. MRM validation revealed evident disparities in 12 specific proteins. The machine learning model found a set of five proteins accurately predicting the occurrence of the disease at a rate of 87.5%, such as alpha 1B-glycoprotein, complement component 4 A, transferrin, V3-3, and defensin alpha 1. These proteins had a functional association with immune inflammation.

CONCLUSIONS

The development of generalised anxiety disorder might be closely linked to the immune inflammatory stress response.

Gender differences in prevalence and clinical risk factors of suicide attempts in young adults with first-episode drug-naive major depressive disorder

BACKGROUND

Suicide rates in adolescents with major depressive disorder (MDD) change with age and gender. Early adulthood is an important transitional stage between late adolescence and adulthood, in which an individual's mind gradually matures. However, there are fewer studies on prevalence and variables linked to the suicide attempts of young adults with MDD.

AIMS

To explore gender differences in the prevalence and risk factors associated with suicide attempts in young adults with first-episode drug-naive MDD.

METHOD

The Hamilton Rating Scale for Depression (HRSD), Hamilton Rating Scale for Anxiety (HRSA) and Positive Subscale of the Positive and Negative Syndrome Scale (PANSS) were used to assess depression, anxiety and psychotic symptoms respectively and various biochemical indicators were assessed.

RESULTS

Among 293 young adults with first-episode drug-naive MDD, the prevalence of suicide attempts was 15.45% (19/123) for males and 14.12% (24/170) for females. Males with suicide attempts had higher levels of thyroid-stimulating hormone (TSH) and higher PANSS Positive Subscale scores, whereas females with suicide attempts had higher TSH, serum total cholesterol, fasting blood glucose and diastolic blood pressure levels and higher scores on the HRSD, HRSA, PANSS Positive Subscale (all Bonferroni corrected P < 0.05). In males, PANSS Positive Subscale score (B = 0.17, P = 0.03, OR = 1.19, 95% CI 1.02-1.38) was a risk factor for suicide attempts.

CONCLUSIONS

There were significant gender differences in the risk factors for suicide attempts in young adults with first-episode drug-naive MDD.

Mismatch negativity and P3a in drug-naive adults with attention-deficit hyperactivity disorder

BACKGROUND

Individuals with attention-deficit hyperactivity disorder (ADHD) often display over-response to stimuli that are irrelevant to the ongoing task, and their attentional abilities disproportionately worsen in the presence of competing stimuli. Auditory event-related potentials (ERPs) such as mismatch negativity (MMN) and P3a using the passive oddball paradigm have been studied in children and adolescents with ADHD. Still, there is no such data for adults with ADHD. This study aimed to compare the MMN and P3a and their clinical and neurocognitive correlations between drug-naive adults with ADHD and control adults.

METHODS

We recruited 52 adults with ADHD (26.5 ± 6.2 years), and 62 age-matched controls (25.6 ± 5.6 years). They received the psychiatric interviews, auditory ERP, the Conners' continuous performance test (CCPT), and the Cambridge gambling test (CGT). They also completed the questionnaires about ADHD symptoms and real-world executive functions. MMN and P3a were assessed during a passive duration-deviant auditory oddball paradigm from the midline electrodes Cz.

RESULTS

Adults with ADHD demonstrated smaller Cz MMN amplitude, more severe ADHD symptoms, poorer attention profiles (CCPT), and a wide range of executive dysfunctions than controls. As for the correlates, Cz peak amplitude of MMN correlated with inattention symptoms, executive dysfunctions, attentional vigilance (CCPT), and decision-making (CGT) in ADHD adults but only with decision-making in controls.

CONCLUSIONS

Our findings that smaller amplitude of MMN and its differential associated pattern with inattention, real-world executive dysfunction, and decision-making, in drug-naive adults with ADHD from adult controls, provide evidence to support the potential electrophysiological biomarker for adult ADHD.

Large-scale dynamic causal modeling of major depressive disorder based on resting-state functional magnetic resonance imaging

Major depressive disorder (MDD) is a serious mental illness characterized by dysfunctional connectivity among distributed brain regions. Previous connectome studies based on functional magnetic resonance imaging (fMRI) have focused primarily on undirected functional connectivity and existing directed effective connectivity (EC) studies concerned mostly task-based fMRI and incorporated only a few brain regions. To overcome these limitations and understand whether MDD is mediated by within-network or between-network connectivities, we applied spectral dynamic causal modeling to estimate EC of a large-scale network with 27 regions of interests from four distributed functional brain networks (default mode, executive control, salience, and limbic networks), based on large sample-size resting-state fMRI consisting of 100 healthy subjects and 100 individuals with first-episode drug-naive MDD. We applied a newly developed parametric empirical Bayes (PEB) framework to test specific hypotheses. We showed that MDD altered EC both within and between high-order functional networks. Specifically, MDD is associated with reduced excitatory connectivity mainly within the default mode network (DMN), and between the default mode and salience networks. In addition, the network-averaged inhibitory EC within the DMN was found to be significantly elevated in the MDD. The coexistence of the reduced excitatory but increased inhibitory causal connections within the DMNs may underlie disrupted self-recognition and emotional control in MDD. Overall, this study emphasizes that MDD could be associated with altered causal interactions among high-order brain functional networks.

Impaired Binocular Depth Perception in First-Episode Drug-Naive Patients With Schizophrenia

Binocular depth perception (BDP) is one of the most demanding visual function that involves both dorsal and ventral visual information streams. Substantial research has been conducted on the disruption of BDP in patients with schizophrenia. However, research on first-episode and drug-naive patients with schizophrenia (FEDN) is limited. To assess the BDP of schizophrenia patients while controlling for the effects of antipsychotics and the duration of illness. We investigated BDP in patients with schizophrenia via the Titmus Stereopsis Test in this study, by matching the patients into three groups: FEDN (n = 17), long duration of illness and medicine treatment (LDMT) (n = 31) and the healthy control group (n = 40). Results showed that both the FEDN (mean = 1.71, 95% confidence interval [CI]: [1.57, 1.84]) and LDMT (1.73, 95% CI: [1.66, 1.81]) patients displayed a significant decline (p = 0.01, Cohen's d = 0.67, p = 0.001, Cohen's d = 0.92, respectively) in depth perception compared to the healthy control (1.55, 95% CI: [1.48, 1.61]) group. Additionally, there were no significant differences (p = 0.68, Cohen's d = 0.11) between the FEDN and LDMT groups, and no correlation (Pearson r = -0.16, p = 0.38, R2 = 0.03) was observed between the duration of illness and impaired BDP in the LDMT group. The proportion of individuals with stereopsis detection in either FEDN (12/17) or LDMT (26/31) groups under stereo threshold 63 arc seconds (″), were significantly lower (Pearson χ2 = 6.29, p = 0.043, φc = 0.27) compared to the healthy control group (38/40). Significant difference in stereopsis detection also occurred at 50″ (Pearson χ2 = 12.31, p = 0.001, φc = 0.37), 40″ (Pearson χ2 = 12.38, p = 0.002, φc = 0.38), 32″ (Pearson χ2 = 6.69, p = 0.035, φc = 0.28), 25″ (Pearson χ2 = 14.82, p = 0.001, φc = 0.41) and 20″ (Pearson χ2 = 6.73, p = 0.034, φc = 0.28) between the three groups. These findings showed a moderately strong association between schizophrenia and defective stereopsis.

Minor hallucinations occur in drug-naive Parkinson's disease patients, even from the premotor phase

OBJECTIVES

The description of minor hallucinatory phenomena (presence, passage hallucinations) has widened the spectrum of psychosis in Parkinson's disease (PD). Minor hallucinatory phenomena seem to antedate the development of more severe hallucinations. Early detection of minor hallucinations may be useful for screening patients with more severe endophenotypes. Motivated by the observation of "de novo," drug-naive PD patients reporting minor hallucinations, we aimed to prospectively identify "de novo" untreated PD patients experiencing hallucinatory phenomena, and to compare their clinico-demographic characteristics with those of untreated PD patients without hallucinations and healthy controls.

METHODS

Screening and description of psychosis was assessed by the Movement Disorders Society Unified Parkinson's Disease Rating Scale-Part I and a structured interview covering all types of psychotic phenomena reported in PD. Clinical, neuropsychological, and demographic data of PD patients with and without psychotic phenomena were compared with those of age- and education-matched healthy controls.

RESULTS

Fifty drug-naive, "de novo" PD patients and 100 controls were prospectively included. Minor hallucinations were experienced in 42% (21 of 50) PD patients and 5% controls (P < 0.0001). Coexistence of passage and presence hallucinations was the most common finding. Unexpectedly, 33.3% of patients with minor hallucinations manifested these as a pre-motor symptom, starting 7 months to 8 years before first parkinsonian motor symptoms. The presence of minor hallucinations was significantly associated with presence of rapid eye movement sleep behavior disorder.

CONCLUSIONS

In this first study to prospectively analyze the frequency of minor hallucinatory phenomena in incident, untreated PD patients, hallucinations appeared as a frequent early non-motor symptom that may even predate the onset of parkinsonism.

Characterization of the deficit syndrome in drug-naive schizophrenia patients: the role of spontaneous movement disorders and neurological soft signs

This study aimed to characterize the deficit syndrome in drug-naive schizophrenia patients and to examine the relationship between deficit features and primary neurological abnormalities. Drug-naive schizophrenia patients (n = 102) were examined at baseline for demographics, premorbid functioning, duration of untreated illness (DUI), psychopathology, neurological signs, and deficit symptoms, and reassessed at 1-year follow-up. Neurological abnormalities were examined before inception of antipsychotic medication and included four domains of spontaneous movement disorders (SMD) and four domains of neurological soft signs (NSS). Patients fulfilling the deficit syndrome criteria at the two assessments (n = 20) were compared with nondeficit patients (n = 82) across demographic, clinical, and neurological variables. Deficit and nondeficit groups showed similar demographic characteristics and levels of psychotic, disorganization, and depressive symptoms. Compared with nondeficit patients, deficit patients showed poorer premorbid adjustment, higher premorbid deterioration, a lengthier DUI, and much poorer functional outcome. Relative to the nondeficit patients, those with the deficit syndrome showed higher levels of SMD--excepting akathisia--and NSS. This association pattern was also evident for deficit and neurological ratings in the whole sample of schizophrenia patients. Parkinsonism, motor sequencing, and release signs were all independently related to the deficit syndrome. These findings confirm that the deficit/nondeficit categorization is replicable and reliable in first-admission patients and raise the possibility that premorbid deterioration, deficit symptoms, and neurological abnormalities represent a triad of manifestations that share common underlying neurobiological mechanisms. More specifically, the data are consistent with a neurodevelopmental model of deficit symptoms involving basal ganglia dysfunction.

EEG alpha coherence and psychopathological dimensions of schizophrenia

The aim of this study was to evaluate the correlation between psychopathological dimensions in recent-onset neuroleptic-naive schizophrenic patients and EEG alpha coherence in the resting state. 37 neuroleptic-naive recent-onset schizophrenic patients were assessed on the Scale for the Assessment of Negative Symptoms and the Scale for the Assessment of Positive Symptoms, and psychopathological dimension scores on reality distortion, psychomotor poverty and disorganization were calculated. EEG alpha coherence was computed across 14 intra-hemispheric and 8 interhemispheric electrode pairs in the resting eyes closed and eyes open conditions. The relationship between the psychopathological dimension scores and coherence values was assessed using Pearson's product moment correlation with Bonferroni correction for levels of significance. Significant associations between higher psychomotor poverty scores and lower inter-hemispheric coherence values were found across the central and parietal regions in the eyes closed condition and across central regions in the eyes open condition. Reality distortion and disorganization dimensions were not significantly correlated with intra- or inter-hemispheric coherences in both eyes closed and eyes open conditions. However there was a trend for an inverse correlation between disorganization dimension and intra-hemispheric coherence across left frontal, left temporo-parietal and right parieto-occipital regions in the eyes open condition. These findings suggest a possible differential pattern in the extent of brain involvement across the three psychopathological dimensions of schizophrenia in neurolepticnaive patients with recent-onset illness.