Event-related potentials to rare visual targets and negative symptom severity in a transdiagnostic psychiatric sample.

OBJECTIVES: Negative psychiatric symptoms are often resistant to treatments, regardless of the disorder in which they appear. One model for a cause of negative symptoms is impairment in higher-order cognition. The current study examined how particular bottom-up and top-down mechanisms of selective attention relate to severity of negative symptoms across a transdiagnostic psychiatric sample. METHODS: The sample consisted of 130 participants: 25 schizophrenia-spectrum disorders, 26 bipolar disorders, 18 unipolar depression, and 61 nonpsychiatric controls. The relationships between attentional event-related potentials following rare visual targets (i.e., N1, N2b, P2a, and P3b) and severity of the negative symptom domains of anhedonia, avolition, and blunted affect were evaluated using frequentist and Bayesian analyses. RESULTS: P3b and N2b mean amplitudes were inversely related to the Positive and Negative Syndrome Scale-Negative Symptom Factor severity score across the entire sample. Subsequent regression analyses showed a significant negative transdiagnostic relationship between P3b amplitude and blunted affect severity. CONCLUSIONS: Results indicate that negative symptoms, and particularly blunted affect, may have a stronger association with deficits in top-down mechanisms of selective attention. SIGNIFICANCE: This suggests that people with greater severity of blunted affect, independent of diagnosis, do not allocate sufficient cognitive resources when engaging in activities requiring selective attention.

Childhood Cat Bites Relate to Increased Adulthood Severity of Schizotypy, Psychotic-Like Experiences, and Social Anhedonia in a Transdiagnostic Psychiatric Sample.

INTRODUCTION: Previous research has linked childhood cat scratches and bites to an increased risk for depression, and childhood cat ownership to increased risk of schizophrenia, bipolar disorder, and social anhedonia. Our group previously reported that childhood cat bites, but not ownership, related to increased schizotypy severity in an undergraduate sample. METHODS: The current study expands this research by inquiring about cat bites and ownership in a transdiagnostic adult sample (N = 162; 51% female; mean age = 38.15, SD = 10.65), composed of schizophrenia spectrum disorders (n = 30), bipolar disorders (n = 30), unipolar depression (n = 23), and nonpsychiatric participants (n = 79). Participants completed a diagnostic interview, scales of symptom severity, and a cat interaction history interview. RESULTS: Across the entire sample, self-report of cat bites prior to age 13, but not after, related to greater current severity of overall schizotypy, self-reported and clinician-rated psychotic-like symptoms, and social anhedonia, when compared to individuals who reported no lifetime cat bites. Cat bites prior to age 13 did not relate to severity of depression, non-social anhedonia, or clinician-rated negative symptoms. Self-report of residing with a cat prior to age 13, or a first cat bite after age 12, did not relate to any symptom severity measure examined. CONCLUSIONS: One theory for these findings is that an unknown infectious agent common in cat saliva interacted with brain development in childhood to increase the likelihood of these symptoms. A novel theory for the infectious agent Pasteurella multocidais discussed. Future research can examine candidate infectious agents to identify potential causal mechanisms for these relationships.

Protective Behavioral Strategies Moderate the Association between Narcissistic Traits and Alcohol Pathology in College Student Drinkers.

BACKGROUND: Personality traits found in Cluster B personality disorders have garnered considerable empirical attention and have been linked to a litany of issues, such as alcohol-related problems. While psychopathic traits have been linked to alcohol-use consequences, narcissistic traits remain understudied. OBJECTIVES: The current study examines the relationship between narcissistic traits and alcohol use and consequences as a function of Protective Behavioral Strategies (PBS) in a sample of college students. METHOD: Participants (n = 387 college student drinkers; 69.25% female) completed a series of questionnaires assessing alcohol use and consequences, PBS use, and narcissistic traits. RESULTS: There was a significant positive association between narcissistic traits and alcohol use and consequences. The interaction of PBS and narcissistic traits was also statistically significant. Simple slopes revealed that at high levels of PBS (+1SD), the relationship between narcissistic traits and alcohol-use consequences was attenuated and not significant, while at low levels of PBS (-1SD), this association was potentiated. CONCLUSION: These findings suggest that interventions targeting PBS use may be one way to reduce alcohol problems among those with higher levels of narcissistic traits.

The P1 visual-evoked potential, red light, and transdiagnostic psychiatric symptoms.

A reduced P1 visual-evoked potential amplitude has been reported across several psychiatric disorders, including schizophrenia-spectrum, bipolar, and depressive disorders. In addition, a difference in P1 amplitude change to a red background compared to its opponent color, green, has been found in schizophrenia-spectrum samples. The current study examined whether specific psychiatric symptoms that related to these P1 abnormalities in earlier studies would be replicated when using a broad transdiagnostic sample. The final sample consisted of 135 participants: 26 with bipolar disorders, 25 with schizophrenia-spectrum disorders, 19 with unipolar depression, 62 with no current psychiatric disorder, and 3 with disorders in other categories. Low (8%) and high (64%) contrast check arrays were presented on gray, green, and red background conditions during electroencephalogram, while an eye tracker monitored visual fixation on the stimuli. Linear regressions across the entire sample (N = 135) found that greater severity of both clinician-rated and self-reported delusions/magical thinking correlated with a reduced P1 amplitude on the low contrast gray (neutral) background condition. In addition, across the entire sample, higher self-reported constricted affect was associated with a larger decrease in P1 amplitude (averaged across contrast conditions) to the red, compared to green, background. All relationships remained statistically significant after covarying for diagnostic class, suggesting that they are relatively transdiagnostic in nature. These findings indicate that early visual processing abnormalities may be more directly related to specific transdiagnostic symptoms such as delusions and constricted affect rather than specific psychiatric diagnoses or broad symptom factor scales.

Structural Relationships Among the Revised Reinforcement Sensitivity Theory and Grandiose and Vulnerable Narcissism.

Research shows that grandiosity and vulnerability are distinct aspects of narcissism. The Contemporary Clinical Model (CCM) of narcissism suggests that individuals fluctuate between grandiose narcissism (GN) and vulnerable narcissism (VN). The authors examine the relative contributions of the Behavioral Approach System (BAS), the Behavioral Inhibition System (BIS), and the Fight-Flight-Freeze System (FFFS) in the Revised Reinforcement Sensitivity Theory of Personality (r-RST) to GN and VN. Few studies examine the r-RST, and even fewer examine the VN and GN distinction. To remain consistent with the CCM, structural equation modeling was used to account for individuals' relative levels of VN and GN. Across two independent samples (Ns = 854 and 258), results indicated that GN is associated with higher BAS scores and that VN is associated with higher BIS scores. Relations among GN, VN, and FFFS were inconsistent between samples. Implications of the r-RST results are interpreted within the context of the CCM.

Transdiagnostic Psychiatric Symptoms and Event-Related Potentials following Rewarding and Aversive Outcomes.

There is a need for a better understanding of transdiagnostic psychiatric symptoms that relate to neurophysiological abnormalities following rewarding and aversive feedback in order to inform development of novel targeted treatments. To address this need, we examined a transdiagnostic sample of 44 adults (mean age: 35.52; 57% female), which consisted of individuals with broadly-defined schizophrenia-spectrum disorders (n = 16), bipolar disorders (n = 10), other mood and anxiety disorders (n = 5), and no history of a psychiatric disorder (n = 13). Participants completed a Pavlovian monetary reward prediction task during 32-channel electroencephalogram recording. We assessed the event-related potentials (ERPs) of feedback-related negativity (FRN), feedback-related positivity (FRP), and the late positive potential (LPP), following better and worse than expected outcomes. Examination of symptom relationships using stepwise regressions across the entire sample revealed that an increase in the clinician-rated Negative Symptoms factor score from the Positive and Negative Syndrome Scale, was related to a decreased LPP amplitude during better than expected (i.e., rewarding) outcomes. We also found that increased self-reported scores on the Schizotypal Personality Questionnaire (Brief-Revised) Disorganized factor related to an increased FRN amplitude during worse than expected (i.e., aversive) outcomes. Across the entire sample, the FRP component amplitudes did not show significant relationships to any of the symptoms examined. Analyses of the three diagnostic groups of schizophrenia-spectrum disorders, bipolar disorders, and nonpsychiatric controls did not reveal any statistically significant differences across the ERP amplitudes and conditions. These findings suggest relationships between specific neurophysiological abnormalities following rewarding and aversive outcomes and particular transdiagnostic psychiatric symptoms.

Metacognitive processes in psychometrically defined schizotypy.

Metacognitive abnormalities have been implicated in the experience of psychotic symptoms; however, the process through which this occurs remains unclear. The aim of this study was to clarify the association of self-reported schizotypy with metacognitive beliefs and neural activity related to higher-order cognition. Event-related potentials (ERPs) including the error-related negativity (ERN) and error positivity (Pe) were recorded during a Flanker task in 20 controls and 22 individuals with high self-reported schizotypy on the Schizotypal Personality Questionnaire-Brief Revised (SPQ-BR). Participants continuously evaluated their task performance and completed the Metacognitions Questionnaire-30 (MCQ-30). The high schizotypy group demonstrated higher scores on all subscales of the MCQ-30. In contrast, task performance, accuracy of self-performance evaluation, and amplitudes of the ERN and Pe did not differ between groups. The MCQ-30 factors that measure cognitive confidence and positive beliefs about worry significantly predicted SPQ-BR total score, whereas ERPs did not. High self-reported schizotypy appears to be more associated with dysfunctional metacognitive beliefs than physiological abnormalities in brain areas related to metacognition.

Genetic determinants of anti-malarial acquired immunity in a large multi-centre study.

BACKGROUND: Many studies report associations between human genetic factors and immunity to malaria but few have been reliably replicated. These studies are usually country-specific, use small sample sizes and are not directly comparable due to differences in methodologies. This study brings together samples and data collected from multiple sites across Africa and Asia to use standardized methods to look for consistent genetic effects on anti-malarial antibody levels. METHODS: Sera, DNA samples and clinical data were collected from 13,299 individuals from ten sites in Senegal, Mali, Burkina Faso, Sudan, Kenya, Tanzania, and Sri Lanka using standardized methods. DNA was extracted and typed for 202 Single Nucleotide Polymorphisms with known associations to malaria or antibody production, and antibody levels to four clinical grade malarial antigens [AMA1, MSP1, MSP2, and (NANP)4] plus total IgE were measured by ELISA techniques. Regression models were used to investigate the associations of clinical and genetic factors with antibody levels. RESULTS: Malaria infection increased levels of antibodies to malaria antigens and, as expected, stable predictors of anti-malarial antibody levels included age, seasonality, location, and ethnicity. Correlations between antibodies to blood-stage antigens AMA1, MSP1 and MSP2 were higher between themselves than with antibodies to the (NANP)4 epitope of the pre-erythrocytic circumsporozoite protein, while there was little or no correlation with total IgE levels. Individuals with sickle cell trait had significantly lower antibody levels to all blood-stage antigens, and recessive homozygotes for CD36 (rs321198) had significantly lower anti-malarial antibody levels to MSP2. CONCLUSION: Although the most significant finding with a consistent effect across sites was for sickle cell trait, its effect is likely to be via reducing a microscopically positive parasitaemia rather than directly on antibody levels. However, this study does demonstrate a framework for the feasibility of combining data from sites with heterogeneous malaria transmission levels across Africa and Asia with which to explore genetic effects on anti-malarial immunity.