Cross-cultural validation of the revised Green et al., paranoid thoughts scale.

BACKGROUND: With efforts increasing worldwide to understand and treat paranoia, there is a pressing need for cross-culturally valid assessments of paranoid beliefs. The recently developed Revised Green et al., Paranoid Thoughts Scale (R-GPTS) constitutes an easy to administer self-report assessment of mild ideas of reference and more severe persecutory thoughts. Moreover, it comes with clinical cut-offs for increased usability in research and clinical practice. With multiple translations of the R-GPTS already available and in use, a formal test of its measurement invariance is now needed. METHODS: Using data from a multinational cross-sectional online survey in the UK, USA, Australia, Germany, and Hong Kong (N = 2510), we performed confirmatory factory analyses on the R-GPTS and tested for measurement invariance across sites. RESULTS: We found sufficient fit for the two-factor structure (ideas of reference, persecutory thoughts) of the R-GPTS across cultures. Measurement invariance was found for the persecutory thoughts subscale, indicating that it does measure the same construct across the tested samples in the same way. For ideas of reference, we found no scalar invariance, which was traced back to (mostly higher) item intercepts in the Hong Kong sample. CONCLUSION: We found sufficient invariance for the persecutory thoughts scale, which is of substantial practical importance, as it is used for the screening of clinical paranoia. A direct comparison of the ideas of reference sum-scores between cultures, however, may lead to an over-estimation of these milder forms of paranoia in some (non-western) cultures.

Predictors of successful discontinuation of antipsychotics and antidepressants.

BACKGROUND: To offer support for patients who decide to discontinue antipsychotic and antidepressant medication, identifying which potentially modifiable factors correlate with discontinuation success is crucial. Here, we analyzed the predictive value of the professional support received, circumstances prior to discontinuation, a strategy of discontinuation, and use of functional and non-functional coping strategies during discontinuation on self-reported discontinuation success and on objective discontinuation. METHODS: Patients who had attempted discontinuing antipsychotics (AP) and/or antidepressants (AD) during the past 5 years (n = 316) completed an online survey including questions on subjective and objective discontinuation success, sociodemographic, clinical and medication-related factors, and scales to assess the putative predictors. RESULTS: A regression model with all significant predictors explained 20-30% of the variance in discontinuation success for AD and 30-40% for AP. After controlling for baseline sociodemographic, clinical and medication-related factors, the most consistent predictor of subjective discontinuation success was self-care behavior, in particular mindfulness, relaxation and making use of supportive relationships. Other predictors depended on the type of medication: For AD, good alliance with the prescribing physician predicted higher subjective success whereas gradual tapering per se was associated with lower subjective success and a lower chance of full discontinuation. In those tapering off AP, leaving time to adjust between dose reductions was associated with higher subjective success and fewer negative effects. CONCLUSIONS: The findings can inform evidence-based clinical guidelines and interventions aiming to support patients during discontinuation. Further studies powered to take interactions between variables into account are needed to improve the prediction of successful discontinuation.

Aberrant adapting of beliefs under stress: a mechanism relevant to the formation of paranoia?

BACKGROUND: Difficulties in the ability to adapt beliefs in the face of new information are associated with psychosis and its central symptom - paranoia. As cognitive processes and psychotic symptoms are both known to be sensitive to stress, the present study investigated the exact associations between stress, adapting of beliefs [reversal learning (RL), bias against disconfirmatory evidence (BADE), and jumping to conclusions (JTC)] and paranoia. We hypothesized that paranoia would increase under stress and that difficulties in adapting of beliefs would mediate or moderate the link between stress and paranoia. Furthermore, we hypothesized that the investigated effects would be strongest in the group of individuals diagnosed with a psychotic disorder. METHODS: We exposed 155 participants (38 diagnosed with a psychotic disorder, 40 individuals with attenuated psychotic symptoms, 39 clinical controls diagnosed with an obsessive-compulsive disorder, and 38 healthy controls) to a control condition and a stress condition, in which we assessed their levels of paranoia and their ability to adapt beliefs. We applied multilevel models to analyze the data. RESULTS: Paranoia was higher in the stress condition than in the control condition, b = 1.142, s.e. = 0.338, t(150) = 3.381, p < 0.001. RL, BADE, and JTC did not differ between conditions and did not mediate or moderate the association between stress and paranoia (all ps > 0.05). CONCLUSIONS: The results support the assumption that stress triggers paranoia. However, the link between stress and paranoia does not seem to be affected by the ability to adapt beliefs.

Pandemic paranoia in the general population: international prevalence and sociodemographic profile.

BACKGROUND: The term 'pandemic paranoia' has been coined to refer to heightened levels of mistrust and suspicion towards other people specifically due to the COVID-19 pandemic. In this study, we examine the international prevalence of pandemic paranoia in the general population and its associated sociodemographic profile. METHODS: A representative international sample of general population adults (N = 2510) from five sites (USA N = 535, Germany N = 516, UK N = 512, Australia N = 502 and Hong Kong N = 445) were recruited using stratified quota sampling (for age, sex, educational attainment) and completed the Pandemic Paranoia Scale (PPS). RESULTS: The overall prevalence rate of pandemic paranoia was 19%, and was highest in Australia and lowest in Germany. On the subscales of the PPS, prevalence was 11% for persecutory threat, 29% for paranoid conspiracy and 37% for interpersonal mistrust. Site and general paranoia significantly predicted pandemic paranoia. Sociodemographic variables (lower age, higher population size and income, being male, employed and no migrant status) explained additional variance and significantly improved prediction of pandemic paranoia. CONCLUSIONS: Pandemic paranoia was relatively common in a representative sample of the general population across five international sites. Sociodemographic variables explained a small but significant amount of the variance in pandemic paranoia.

Effectiveness of a transdiagnostic emotion regulation training in an at-risk sample: a randomized-controlled trial of group-based training versus self-help bibliotherapy.

OBJECTIVES: Subclinical psychotic, depression, and anxiety symptoms form a transdiagnostic 'at-risk state' for the development of mental disorders. Emotion regulation has been identified as a transdiagnostic factor relevant to the formation of these symptoms that can be successfully addressed in clinical interventions. Here, we tested whether a group-based emotion regulation training would be effective in reducing distress and at preventing the transition to mental disorders in an at-risk sample. METHODS: Participants with distressing subclinical psychotic, depression, or anxiety symptoms (n = 138) were randomly allocated to either the 8-week group-based affect regulation training (ART; Springer, New York) or an 8-week self-help bibliotherapy (BT). They underwent biweekly measurements during the intervention, as well as at a six- and 12-month follow-up. In an exploratory analysis, we tested whether the ART would be superior to BT in preventing the transition to any mental disorder at 12-month follow-up. We also tested for differences in trajectories of psychopathology and emotion regulation (via questionnaires) and emotion regulation in daily life (via the experience-sampling method). RESULTS: Participants in the ART condition showed a greater improvement of emotion regulation in daily life than those with BT, but the ART was not superior over BT in preventing the transition to mental disorders. There were significant longitudinal reductions from pre- to post-intervention for general psychopathology and symptoms but no superiority of the ART over BT. CONCLUSIONS: Despite its efficacy in improving emotion regulation skills, the ART does not produce effects on psychopathology that justify its recommendation over self-help approaches.

Comparing psychotic experiences in low-and-middle-income-countries and high-income-countries with a focus on measurement invariance.

BACKGROUND: The prevalence of psychotic experiences (PEs) is higher in low-and-middle-income-countries (LAMIC) than in high-income countries (HIC). Here, we examine whether this effect is explicable by measurement bias. METHODS: A community sample from 13 countries (N = 7141) was used to examine the measurement invariance (MI) of a frequently used self-report measure of PEs, the Community Assessment of Psychic Experiences (CAPE), in LAMIC (n = 2472) and HIC (n = 4669). The CAPE measures positive (e.g. hallucinations), negative (e.g. avolition) and depressive symptoms. MI analyses were conducted with multiple-group confirmatory factor analyses. RESULTS: MI analyses showed similarities in the structure and understanding of the CAPE factors between LAMIC and HIC. Partial scalar invariance was found, allowing for latent score comparisons. Residual invariance was not found, indicating that sum score comparisons are biased. A comparison of latent scores before and after MI adjustment showed both overestimation (e.g. avolition, d = 0.03 into d = -0.42) and underestimation (e.g. magical thinking, d = -0.03 into d = 0.33) of PE in LAMIC relative to HIC. After adjusting the CAPE for MI, participants from LAMIC reported significantly higher levels on most CAPE factors but a significantly lower level of avolition. CONCLUSION: Previous studies using sum scores to compare differences across countries are likely to be biased. The direction of the bias involves both over- and underestimation of PEs in LAMIC compared to HIC. Nevertheless, the study confirms the basic finding that PEs are more frequent in LAMIC than in HIC.

The effect of salience of rewards on effort-based decision making in psychotic disorders.

BACKGROUND: Although motivational negative symptoms account for reduced functioning and quality of life in individuals with psychotic disorders, the underlying mechanisms are yet not fully understood. Neuroimaging studies suggest that an impaired perception of reward cues could result in a lack of incentive value that then leads to a decrease in goal-directed behavior. Therefore, the aim of this study was to test the effect of increasing the salience of reward cues on goal-directed behavior. METHODS: We recruited a sample of n = 30 participants with a psychotic disorder and at least mild negative symptoms and n = 30 healthy controls. We used the Balloon Effort Task, an effort-based decision-making paradigm, to assess amotivation on a behavioral level. We manipulated the salience of rewards in the paradigm by highlighting the monetary rewards in half of the trials. RESULTS: Total effort expenditure did not differ between participants with and without psychotic disorders, but participants with psychotic disorders showed a significantly reduced effort allocation to the level of rewards. The salience of rewards manipulation significantly increased effort expenditure both in participants with psychotic disorders and in the healthy controls, but had no impact on effort allocation. CONCLUSIONS: Increasing the salience of reward cues promotes goal-directed behavior. This opens up new possibilities for interventions addressing amotivation in individuals with negative symptoms by facilitating the perception of reward cues.

Does social defeat cause negative symptoms? A prospective study in a multi-national community sample.

Psychological models of the consequences of ostracism (i.e. being socially excluded and ignored) and negative symptoms in schizophrenia suggest that repeatedly experiencing ostracism can lead to elevated levels of amotivation, anhedonia, and asociality (i.e. negative symptoms). We tested this assumption in a prospective study, following up a large multi-national community sample from Germany, Indonesia, and the United States (N = 962) every four months over one year. At each of the four assessment points (T0 - T3), participants rated their recent ostracism experiences and negative symptoms. Using cross-lagged panel analyses we found a) that negative symptoms and experiences of ostracism were significantly associated in each of the four assessment points, b) that ostracism predicted negative symptoms over time (T2 to T3), and c) that negative symptoms increased ostracism (T0 to T1). The results are in line with the social defeat model of negative symptoms and suggest a bi-directional longitudinal relationship between ostracism and negative symptoms. Moving forward, it will therefore be important to gain an understanding of potential moderators involved in the mechanism.

Increasing motivation in effort-based decision-making tasks: effects of salience and reward expectancy manipulations.

BACKGROUND: A significant proportion of patients with affective and psychotic disorders show a marked reduction in goal-directed behaviour, which is also reflected in the behavioural outcomes of effort-based decision-making paradigms. The factors underlying this reduction are not yet fully understood. Reward salience and reward expectancy have been discussed as factors that potentially influence approach behaviour. The aim of this study was thus to test their effects on behaviour in an effort-based decision-making paradigm. METHODS: In two studies with community samples we applied a modified version of the Balloon Task. In study 1, we manipulated reward salience in a within-subject design (N = 32) by highlighting the monetary rewards. In study 2, we manipulated reward expectancy in a between-subject design (N = 72) by adding five practice trials with either positive or negative feedback prior to the task. RESULTS: The salience of rewards manipulation significantly increased effort expenditure and the allocation of effort to the level of rewards whereas the reward expectancy manipulation did not. CONCLUSIONS: The finding that increasing the salience of rewards increases motivated behaviour in an effort-based decision-making paradigm offers promising possibilities for intervention in disorders characterised by motivational deficits, such asaffective and psychotic disorders.

How you think about an emotion predicts how you regulate: an experience-sampling study.

Emotion evaluations are assumed to play a crucial role in the emotion regulation process. We tested a postulate from our framework of emotion dysregulation (Nowak, U., Wittkamp, M. F., Clamor, A., & Lincoln, T. M. [2021]. Using the Ball-in-Bowl metaphor to outline an integrative framework for understanding dysregulated emotion. Frontiers in Psychiatry, 12, 118), namely that the extent to which individuals evaluate an emotion as harmful and their personal resources to modify and accept/tolerate the emotion as sufficient predict the subsequent use of regulation strategies. Participants (n = 118) from a community sample took part in an experience-sampling assessment over 7 days including 10 daily paired measurements. The first measured momentary affective valence and arousal along with harmfulness evaluations and evaluations of personal resources to modify and accept/tolerate an emotion. The second followed three minutes later and measured emotion regulation strategies. The more harmful individuals evaluated an emotion, the more likely they were to use an emotion regulation strategy. The more harmful individuals evaluated an emotion, and the less sufficient they evaluated their personal resources to accept/tolerate an emotion, the more likely they were to use a maladaptive emotion regulation strategy. We conclude that emotions that people evaluate as harmful or difficult to accept are most likely to be regulated in a maladaptive manner. This implies that modifying beliefs about emotions could represent a promising treatment approach.

Predictors of attendance in outpatient group treatment for women with posttraumatic stress disorder and substance use disorder.

Objective: The present study investigated predictors of treatment attendance among 226 women with posttraumatic stress disorder (PTSD) and substance use disorder (SUD). Participants received either an integrated intervention for PTSD and SUD ("Seeking Safety") or a relapse prevention training (RPT) as part of a multicenter randomized controlled trial. Method: Beta-binomial regression was conducted to investigate baseline sociodemographic, motivational, mental health and substance use predictors of session attendance. Treatment by predictor interactions were included to identify treatment-specific predictors. Results: Session attendance was predicted by employment status, drug use severity and abstinence status. Higher drug use severity and unemployment were associated with less session attendance. The effect of abstinence status was treatment-specific, with abstinent participants in RPT attending most sessions. Conclusions: Considering individual characteristics could enhance session attendance in outpatient treatment for women with PTSD and SUD. This might include matching treatment concepts to abstinence status, the identification of attendance barriers in unemployed women and more intensive treatment settings for those with severe drug use.

[Modern cognitive behavior therapy of psychotic disorders]. / Moderne kognitive Verhaltenstherapie bei psychotischen Störungen.

The current treatment guidelines recommend several effective psychotherapeutic approaches for different indications or aims in the therapy of patients with psychotic disorders. In particular, cognitive behavior therapy (CBTp) is recommended for the treatment of positive and general symptoms in all phases of the disorder without any restriction. Although CBTp could be easily implemented in routine care, very few of the affected patients have access to this evidence-based procedure in inpatient or outpatient settings. The interventions in CBTp directly address the psychotic symptoms themselves as well as the factors involved in the development and maintenance of symptoms. The core features of CBTp are a normalizing attitude of the therapist towards symptoms, an individualized approach and cognitive interventions. Recent developments include symptom-specific, metacognitive as well as mindfulness and acceptance-based approaches. Moreover, the reduction of comorbid symptoms can add to the benefit of the treatment. This article provides an overview of the basic CBTp techniques and of some of the latest developments in this field. It is hoped that this will contribute to the training of therapists and to the better implementation of evidence-based and guideline-based psychotherapy in the care of patients with psychotic disorders.

Traumatic Experiences, Revictimization and Posttraumatic Stress Disorder in German Inpatients Treated for Alcohol Dependence.

BACKGROUND: Traumatic experiences and posttraumatic stress disorder (PTSD) are prevalent in patients with alcohol use disorders (AUDs) and affect its course and outcome. Prior prevalence reports are limited by the inclusion of individuals with additional substance use disorders (SUDs), a focus on childhood events only and the use of self-ratings only. OBJECTIVES: To examine the prevalence of traumatic experiences, revictimization and PTSD in inpatients treated for alcohol dependence without other SUD, emphasizing interpersonal violence across the whole lifespan. METHODS: For this cross-sectional study alcohol-dependent patients without additional SUD (N = 230, 73% male, mean age 43 years) were recruited in an inpatient detoxification unit and were administered the Structured Trauma Interview, the Posttraumatic Diagnostic Scale, and the Structured Clinical Interview for DSM-IV. Data analysis comprised descriptive statistics and appropriate significance tests. RESULTS: 36.2% reported severe childhood physical or sexual abuse and 45.6% reported at least one of these types of abuse in adulthood. The lifetime rate of interpersonal violence was 61.1%. The prevalence of current PTSD was 13.2%. Women with a history of childhood abuse were about seven times as likely to be victimized in adulthood as women without these experiences, while in men revictimization was not significant. CONCLUSIONS: Even in patients with alcohol dependence without additional SUD experiences of interpersonal violence and PTSD are frequent. In order to adequately respond to the needs of this population, trauma and PTSD should routinely be assessed in alcohol-dependence treatment and considered in treatment planning if necessary.

Sleeping Paranoia Away? An Actigraphy and Experience-Sampling Study with Adolescents.

Paranoid symptoms co-occur with distress and poor functioning and constitute a risk for psychosis and other mental disorders. Poor sleep is known to be associated with paranoid symptoms, but the direction of the effect and the mediating factors have not been studied thoroughly. In an experience-sampling study, 61 adolescents wore an actigraph over eight nights and also rated their sleep, symptoms of paranoia, and potentially mediating factors. Shorter sleep time and more dreaming predicted paranoid symptoms in multilevel regression models. Paranoid symptoms did not significantly predict sleep parameters. Positive and negative affect partially mediated the effect of sleep time on paranoid symptoms. The effects were small, but encourage further research that might then be used to improve the prevention of paranoid symptoms.

Are Schemas Passed on? A Study on the Association Between Early Maladaptive Schemas in Parents and Their Offspring and the Putative Translating Mechanisms.

BACKGROUND: According to Young's schema theory, Early Maladaptive Schemas (EMSs) arise due to the violation of core emotional needs during childhood. It seems likely that parents have difficulties in satisfying their children's emotional needs if they have high levels of EMSs themselves. AIMS: This study investigated whether the extent of EMSs in parents is associated with the extent of EMSs in their offspring. Moreover, we tested for two putative mechanisms that account for this association: parental coping styles and parenting behaviour. METHODS: Sixty dyads of parents (mother or father) and their adult children (N = 120), recruited from the general population, completed the Young Schema Questionnaire. The parents rated their schema coping styles and the children retrospectively rated the parenting of the participating parent. RESULTS: As expected, parents' EMSs were significantly associated with EMSs in their offspring. This association was accounted for by the parental coping style Overcompensation and the adverse parenting that the child remembered. The parental coping style Avoidance did not account for the association. CONCLUSIONS: This study provides preliminary evidence for the notion that EMSs are passed on from one generation to the next via parental coping and parenting. Our findings thus support the assumption of schema theory that EMSs are connected to the family environment in terms of adverse parenting. If further confirmed, this has relevant implications for family-based interventions.

The predictive value of early maladaptive schemas in paranoid responses to social stress.

BACKGROUND: Social stress and negatively valenced cognitive representations of the self (self-schemas) play an important role in the formation of delusions. However, it has not been investigated whether and which self-schemas explain paranoid responses to social stress. Building on the framework of schema theory, the aim of this study was thus to investigate whether more pronounced early maladaptive schemas (EMSs) were associated with increased paranoid ideation after a social stress induction in patients with persecutory delusions (PD). METHOD: Patients with PD (n = 20) and healthy controls (n = 40) were assessed for EMSs with the Young Schema Questionnaire. They were then exposed to a social stress situation in which they were socially excluded in a Cyberball paradigm. Prior to and after the social stress induction, paranoid symptoms were assessed. RESULTS: Patients with PD responded with a stronger increase in paranoia and revealed a significantly higher EMS total score compared to the healthy controls. As expected, higher increases in paranoia following the social stress were accounted for by higher EMS total scores. Exploratory analyses showed that particularly the specific EMSs Defectiveness/Shame and Enmeshment/Undeveloped Self were associated with the increase in paranoia. CONCLUSIONS: EMSs are associated with stress-related symptom increases in patients with PD. It thus seems worthwhile to further investigate the relevance of specific schemas for paranoia. The findings also suggest that addressing EMSs in psychological treatment of patients with PD holds potential.

The lonely road to paranoia. A path-analytic investigation of loneliness and paranoia.

Loneliness and paranoia are related, but the mechanisms that link them to each other remain unclear. Systematic reviews on loneliness propose a social-cognitive model in which loneliness leads to negative evaluations of other persons and a lack of interpersonal trust. However, the data discussed in these reviews are based on healthy individuals. Building on this model, the present study investigated 1) whether negative interpersonal schemata mediate the association between loneliness and paranoia and 2) whether a low level of perceived social support and less frequent social contact are related to loneliness. Using a cross-sectional design, sixty-five participants with a diagnosis of schizophrenia were recruited online and completed questionnaire-based measures of loneliness, paranoia, negative interpersonal schemata, perceived social support and frequency of social contact. Data were analyzed taking a path-analytic approach. The association between loneliness and paranoia was significantly and fully mediated by negative schemata of others. Moreover, a low level of perceived social support was significantly associated with loneliness, whereas self-reported frequency of social contact was not. The present results highlight the potential role of interpersonal negative schemata in the formation and maintenance of paranoia and elucidate the crucial role of loneliness in the way individuals construe themselves within a social environment.

Associations of attention-deficit/hyperactivity and other childhood disorders with psychotic experiences and disorders in adolescence.

Prodromal symptoms of psychosis are associated with an increased risk of transition, functional impairment, poor mental health, and unfavorable developmental prospects. Existing interventions targeting the prodrome are non-satisfactory. It may thus be more promising to attempt to identify risk factors in the premorbid phase preceding the prodrome to increase the chances of successful preventive approaches. Here, we investigate whether childhood mental disorders in general and attention-deficit/hyperactivity disorder (ADHD) specifically indicate a risk for subsequent psychotic experiences and disorders. We used a sample from the prospective Avon Longitudinal Study of Parents and Children (N = 5528). When the participants were 7 years old, mental disorders were assigned according to the DSM-IV. In standardized interviews, psychotic experiences were assessed at age 12 and psychotic disorders at age 18. We examined the associations of each of the childhood mental disorders alone and in combination with psychotic experiences at age 12 and psychotic disorders at age 18 using logistic regression. Compared to participants without a disorder, participants with a mental disorder had a higher risk of psychotic experiences at age 12 (OR 1.70, 95 % CI 1.28-2.27) and of psychotic disorders at age 18 (OR 2.31, 95 % CI 1.03-5.15). Particularly, the ADHD combined subtype at age 7 was strongly associated with psychotic experiences at age 12 (OR 3.26, 95 % CI 1.74-6.10). As expected, childhood mental disorders are risk indicators of psychotic experiences and disorders. To improve prevention, health care professionals need to screen for psychotic experiences in children with non-psychotic disorders.

Feasibility and Effects of a Brief Compassion-Focused Imagery Intervention in Psychotic Patients with Paranoid Ideation: A Randomized Experimental Pilot Study.

Paranoia is characterized by a lack of perceived social safeness and associated negative affect. Low self-esteem, negative self-concepts and negative emotions have been shown to contribute to paranoid symptom formation. Thus, interventions focusing on affiliation and positive affect might be particularly helpful for patients with paranoia. The present study experimentally tested the effect of a one-session, brief compassion-focused imagery derived from Compassion-Focused Therapy (Gilbert, ) versus a control imagery condition in a repeated measures randomized design. A negative affective state was induced via in-sensu exposure to a recent distressful social situation in order to provide a minimum level of threat-related arousal to be down-regulated by the interventions thereafter. The sample consisted of psychotic patients with paranoid ideation (N = 51) who were randomly assigned to one of the experimental conditions. Effects on postulated causal mechanisms, i.e., self-relating (self-reassurance, self-compassion, self-criticism), and affect (self-reported affective states, skin conductance levels) as well as on state paranoia, were tested. Subjective benefit and appraisals of the intervention were explored. There were no specific intervention effects on negative self-relating, negative affect and skin-conductance or on paranoia. However, compassion-focused imagery had significant effects on self-reassurance and happiness. Explorative analyses revealed that the majority of the participants appraised the intervention in a positive manner, indicating good acceptance. The intervention showed an effect on some of the postulated mechanisms but not on others, which might have been because of its brevity. Further investigation of interventions targeting affiliation for people with paranoid experiences appears worthwhile. Copyright © 2016 John Wiley & Sons, Ltd. KEY PRACTITIONER MESSAGE: Affiliative imagery work is feasible and appraised positively in psychotic patients. Brief compassion focused imagery increased feelings of happiness and reassurance but did not improve negative self-relating, negative affect or paranoia. Further investigation is warranted to identify which patients benefit most from affiliative imagery.

Resting vagal activity in schizophrenia: meta-analysis of heart rate variability as a potential endophenotype.

BACKGROUND: Cardiac vagal tone, indexed by heart rate variability (HRV), is a proxy for the functional integrity of feedback mechanisms integrating central and peripheral physiology. AIMS: To quantify differences in HRV in individuals with schizophrenia compared with healthy controls. METHOD: Databases were systematically searched for studies eligible for inclusion. Random effect meta-analyses of standardised mean differences were calculated for vagal activity indicated by high-frequency HRV and the root mean square of successive R-R interval differences (RMSSD). RESULTS: Thirty-four studies were included. Significant main effects were found for high-frequency HRV (P = 0.0008; Hedges' g = -0.98, 95% CI -1.56 to -0.41, k = 29) and RMSSD (P<0.0001; g = -0.91, 95% CI -1.19 to -0.62, k = 24), indicating lower vagal activity in individuals with schizophrenia than in healthy controls. Considerable heterogeneity was evident but effects were robust in subsequent sensitivity analyses. CONCLUSIONS: Given the association between low HRV, threat processing, emotion regulation and executive functioning, reduced vagal tone may be an endophenotype for the development of psychotic symptoms.