Ambulatory Heart Rate Variability in Schizophrenia or Depression: Impact of Anticholinergic Burden and Other Factors

Assessment of symptom severity in psychotic disorder patients based on heart rate variability and accelerometer mobility data

BACKGROUND

Advancement in mental health care requires easily accessible, efficient diagnostic and treatment assessment tools. Viable biomarkers could enable objectification and automation of the diagnostic and treatment process, currently dependent on a psychiatric interview. Available wearable technology and computational methods make it possible to incorporate heart rate variability (HRV), an indicator of autonomic nervous system (ANS) activity, into potential diagnostic and treatment assessment frameworks as a biomarker of disease severity in mental disorders, including schizophrenia and bipolar disorder (BD).

METHOD

We used a commercially available electrocardiography (ECG) chest strap with a built-in accelerometer, i.e. Polar H10, to record R-R intervals and physical activity of 30 hospitalized schizophrenia or BD patients and 30 control participants through ca. 1.5-2 h time periods. We validated a novel approach to data acquisition based on a flexible, patient-friendly and cost-effective setting. We analyzed the relationship between HRV and the Positive and Negative Syndrome Scale (PANSS) test scores, as well as the HRV and mobility coefficient. We also proposed a method of rest period selection based on R-R intervals and mobility data. The source code for reproducing all experiments is available on GitHub, while the dataset is published on Zenodo.

RESULTS

Mean HRV values were lower in the patient compared to the control group and negatively correlated with the results of the PANSS general subcategory. For the control group, we also discovered the inversely proportional dependency between the mobility coefficient, based on accelerometer data, and HRV. This relationship was less pronounced for the treatment group.

CONCLUSIONS

HRV value itself, as well as the relationship between HRV and mobility, may be promising biomarkers in disease diagnostics. These findings can be used to develop a flexible monitoring system for symptom severity assessment.

Medication impact on oral health in schizophrenia

BACKGROUND

Patients with schizophrenia constitute a particularly vulnerable group for oral diseases. Among the different factors involved, we aimed to examine the evidence of how drugs could contribute to the poorer oral health of this population.

MATERIAL AND METHODS

An overview of the potential impact of medication on dental/oral health among people with schizophrenia was proposed focusing on selected literature.

RESULTS

Studies show a higher dental caries and degree of periodontal diseases in this population and point to drug-induced xerostomia as an important risk factor for oral health deterioration. The risk of dry mouth depends on not only antipsychotics, but also drugs with anticholinergic activity. We hypothesize that antipsychotic induced glycaemic alterations might contribute to reduced oral health, and that the antimicrobial activity of certain antipsychotics could have an impact on oral microbiota affecting oral condition. Pharmacovigilance data show that involuntary movements are caused by typical and some atypical antipsychotics. Dry mouth is most frequently reported for quetiapine and olanzapine, while clozapine is more frequently associated with sialorrhea.

CONCLUSIONS

Literature clearly shows higher caries and periodontal disease in schizophrenic patients. However, overall, there is scarce literature about the potential influence of drugs in these disorders. Health professionals should be aware of this issue in order to implement adequate preventive measures in this vulnerable population.

The relationship between heart rate variability and TNM stage, co-morbidity, systemic inflammation and survival in patients with primary operable colorectal cancer

High vagal nerve activity, reliability measured by HRV, is considered protective in cancer, reducing oxidative stress, inflammation and opposing sympathetic nerve activity. The present monocentric study examines the relationship between HRV, TNM stage, co-morbidity, systemic inflammation and survival in patients who underwent potentially curative resections for colorectal cancer (CRC). Time-domain HRV measures, Standard Deviation of NN-intervals (SDNN) and Root Mean Square of Successive Differences (RMSSD), were examined as categorical (median) and continuous variables. Systemic inflammation was determined using systemic inflammatory grade (SIG) and co-morbidity using ASA. The primary end point was overall survival (OS) and was analysed using Cox regression. There were 439 patients included in the study and the median follow-up was 78 months. Forty-nine percent (n = 217) and 48% (n = 213) of patients were categorised as having low SDNN (< 24 ms) and RMSSD (< 29.8 ms), respectively. On univariate analysis, SDNN was not significantly associated with TNM stage (p = 0.830), ASA (p = 0.598) or SIG (p = 0.898). RMSSD was not significantly associated with TNM stage (p = 0.267), ASA (p = 0.294) or SIG (p = 0.951). Neither SDNN or RMSSD, categorical or continuous, were significantly associated with OS. In conclusion, neither SDNN or RMSSD were associated with TNM stage, ASA, SIG or survival in patients undergoing potentially curative surgery for CRC.

Emotion regulation relates to clinical characteristics and quality of life but not daily functioning in psychosis spectrum outpatients

Difficulties in emotion regulation (ER) can negatively impact the clinical course and outcomes of a range of psychiatric conditions, including psychosis spectrum disorders. Individuals with psychosis may exhibit poorer ER abilities, which have been associated with increased severity and distress of psychotic symptoms. A paucity of research has investigated the clinical correlates of ER in psychosis and the influence of these difficulties on indices of recovery, such as daily functioning and quality of life. In the present study, 59 outpatients presenting for Cognitive Behaviour Therapy for psychosis (CBTp) in a large psychiatric hospital completed an intake assessment of clinician-rated and self-reported measures prior to treatment. Poor ER abilities were positively correlated with positive symptoms (overall and delusions), social anxiety, depression, and self-reflectiveness and negatively correlated with quality of life and personal recovery. Multiple regression analyses showed ER was a significant predictor of quality of life but not daily functioning, which was predicted most by cognition and psychiatric symptoms. Overall, findings support the clinical utility of assessing emotion dysregulation in psychosis and provide a more nuanced understanding of how such challenges differentially influence recovery in psychosis, which can further inform treatment planning and intervention.

Patient-reported exposures and outcomes link the gut-brain axis and inflammatory pathways to specific symptoms of severe mental illness

We developed a "gut-brain-axis questionnaire" (GBAQ) to obtain standardized person-specific "review of systems" data for microbiome-gut-brain-axis studies. Individual items were compared to PANSS symptom measures using dimensional, transdiagnostic and traditional categorical approaches.

METHOD

Forty psychotic participants, independent of diagnoses, and 42 without psychosis (18 nonpsychotic affective disorders, 24 healthy controls) completed the GBAQ and underwent research diagnostic and symptom assessments. The PANSS scales and its dysphoric mood, autistic preoccupation and activation factors were computed.

RESULTS

Transdiagnostic analyses robustly linked psychosis severity to constipation (p<.001), and Negative (p=.045) and General Psychopathology scores (p=.016) with bowel hypomotility. Activation factor scores predicted numbers of psychiatric (p=.009) and medical conditions (p=.003), BMI (p=.003), skin (p<.001) and other conditions. Categorical analyses comparing psychotic, nonpsychotic and control groups revealed behavioral differences: cigarette smoking (p=.013), alcohol use (p=.007), diet (p's <.05), exercise (p<.001). All subjects accurately self-reported their diagnosis.

CONCLUSIONS

The GBAQ is a promising tool. Transdiagnostic analyses associated psychotic symptoms to gut hypomotility, indicative of low gut vagal tone, consistent with reduced cardiovagal activity in psychosis. Activation, similar to delirium symptoms, predicted medical comorbidity and systemic inflammatory conditions. Group level comparisons only showed behavioral differences. Underpinnings of psychiatric disorders may include reduced gut vagal function, producing psychosis, and systemic inflammation, impacting risks for psychotic and nonpsychotic conditions.

Heart Rate Variability in Schizophrenia and Autism

Suppressed heart rate variability (HRV) has been found in a number of psychiatric conditions, including schizophrenia and autism. HRV is a potential biomarker of altered autonomic functioning that can predict future physiological and cognitive health. Understanding the HRV profiles that are unique to each condition will assist in generating predictive models of health. In the current study, we directly compared 12 adults with schizophrenia, 25 adults with autism, and 27 neurotypical controls on their HRV profiles. HRV was measured using an electrocardiogram (ECG) channel as part of a larger electroencephalography (EEG) study. All participants also completed the UCLA Loneliness Questionnaire as a measure of social stress. We found that the adults with schizophrenia exhibited reduced variability in R-R peaks and lower low frequency power in the ECG trace compared to controls. The HRV in adults with autism was slightly suppressed compared to controls but not significantly so. Interestingly, the autism group reported feeling lonelier than the schizophrenia group, and HRV did not correlate with feelings of loneliness for any of the three groups. However, suppressed HRV was related to worse performance on neuropsychological tests of cognition in the schizophrenia group. Together, this suggests that autonomic functioning is more abnormal in schizophrenia than in autism and could be reflecting health factors that are unique to schizophrenia.