- Email: [email protected]
Neural correlates of paranoia: An ERP study of clinically anxious and healthy participants
IOP 2016
107
357
358
Modelling complex relationships between physiological and psychosocial factors in depression
Neural correlates of paranoia: An ERP study of clinically anxious and healthy participants
Susan J. Thomasa, Peter R.C. Leesona, Theresa Larkina, Chao Denga,b, Brahmavar Nagesh Paia, Jessica Millsa, Peter McLennana a Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, Australia b Illawarra Health and Medical Research Institute, Wollongong, Australia
Susan J. Thomasa, Craig J. Gonsalvezb, Stuart J. Johnstonea a University of Wollongong Australia, Wollongong, Australia b University of Western Sydney, Sydney, Australia
Background: Depression is a major cause of morbidity and death globally, and its incidence is increasing. Increases have been linked to modern dietary changes, stress, loneliness, sleep deprivation and endocrine dysfunction. Its diagnostic criteria span psychological and physical symptoms, including low mood, negative thinking and changes in sleep, appetite and weight. Additionally, there are strong relationships between depression and physical health, particularly heart disease. Key biomarkers identified to operate at the nexus of physical and mental health include cortisol, oxytocin, omega-3 fatty acids and leptin. While these show potential for novel therapeutic strategies, studies show inconsistent results, likely due to complex interactions between biopsychosocial variables and heterogeneous symptom subtypes. Structural equation modelling (SEM) is an analytical technique allowing examination of complex interactions between variables that predict important outcomes, such as illness. SEM has been extensively applied to coronary heart disease to identify points for interventions among numerous lifestyle and physical factors. As yet, similar, comprehensive models of depression are lacking. Developing and testing complex models including key biological and psychosocial variables may lead to improved interventions. Method: We quantified plasma cortisol, oxytocin, omega-3 fatty acid and leptin levels in 60 healthy participants and 60 meeting DSM-5 criteria for Major Depressive Disorder who were not receiving treatment. Participants completed detailed measures of psychopathology, stress, quality of life, psychosocial functioning, cognitive distortions and lifestyle data. Other physiological healthrelated measures included BMI, heat-rate, blood pressure and waist circumference. We employed correlational analyses and SEM using AMOS to test hypotheses about relationships between key physiological and psychological variables. Results: Several individual biomarkers showed distinct relationships with psychopathology, distress, quality of life, psychosocial functioning and cognition. In particular, cortisol levels were related to stress, psychopathology, perceived lack of social support and depressive cognitive distortions. Oxytocin levels were inversely associated with psychopathology and positively associated with perceived social support. Physiological health indices including heart rate and blood pressure were related both to specific psychopathological symptoms and to hormone levels. These relationships were further explored through SEM. Discussion: This study identified new information about links between several key biomarkers and specific symptoms in depression. Our application of SEM allows more complex understanding of the strength and direction of relationships between psychophysiological variables associated with depression. Further, large scale, studies are needed. Conclusion: This approach shows promise for increasing understanding of biological trajectories towards depression and ill health, which may potentially lead to targeted early interventions.
doi:10.1016/j.ijpsycho.2016.07.323
Background: Paranoia is a common trans-diagnostic psychological symptom involving thoughts and feelings of irrational mistrust, suspicion, persecution, threat or conspiracy. Paranoia occurs most commonly in psychotic disorders but also commonly occurs in other mental disorders and on a continuum in the general population. It is often associated with anxiety, hostility, hypervigilance and defensiveness. The psychophysiological processes involved in paranoia are not fully understood. Paranoia has been variously hypothesised to reflect disturbances in early perceptual processing, impaired emotional processing or regulation, impulsivity in terms of jumping to conclusions, or impairment in reasoning ability to assign meanings. Previous studies of paranoia have largely relied on self-report methodology. The high temporal resolution of event-related potentials (ERPS) allows the study of brain electrical activity during information-processing associated with early perceptual processing versus relatively more complex stages of inhibition and cognition. ERPs may thus be able to locate informationprocessing stages associated with anomalous brain activity in paranoia, to differentiate between explanations and improve understanding of this common symptom. Method: We examined ERPs in 60 participants, 20 with a diagnosed anxiety disorder, 20 with obsessive-compulsive disorder and 20 healthy controls. Paranoid ideation was assessed using the Brief Symptom Inventory (BSI). ERP components were measured during implicit and explicit attention tasks involving emotionally threatening and neutral stimuli. Hierarchical multiple regressions were performed. Results: Paranoid ideation showed correlations with amplitudes of multiple ERP components, however associations were strongest for the P3 component. In particular, P3 amplitude to emotionally threatening stimuli in the implicit attention task was inversely correlated with Paranoia. No sex differences were found. Discussion: The findings demonstrate that multiple processing stages are related to Paranoid Ideation, however there appears to be a greater involvement of cognitive processes reflected in the P3 component in Paranoid Ideation than those associated with other, earlier components. The results are consistent with previous observations that paranoid ideation may be particularly related to individuals’ attempts to interpret ambiguous (implicit) emotional arousal. Additionally they are consistent with findings of inverse correlations between psychotic symptoms and P3 amplitudes in several studies. Conclusion: The results have potential implications for cognitive models and interventions addressing paranoia.
doi:10.1016/j.ijpsycho.2016.07.324
405 Automatic categorization of brief changes of facial expression with fast periodic visual stimulation in EEG Bruno Rossion, Milena Dzhelyova University of Louvain, Louvain-la-Neuve, Belgium
107
357
358
Modelling complex relationships between physiological and psychosocial factors in depression
Neural correlates of paranoia: An ERP study of clinically anxious and healthy participants
Susan J. Thomasa, Peter R.C. Leesona, Theresa Larkina, Chao Denga,b, Brahmavar Nagesh Paia, Jessica Millsa, Peter McLennana a Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, Australia b Illawarra Health and Medical Research Institute, Wollongong, Australia
Susan J. Thomasa, Craig J. Gonsalvezb, Stuart J. Johnstonea a University of Wollongong Australia, Wollongong, Australia b University of Western Sydney, Sydney, Australia
Background: Depression is a major cause of morbidity and death globally, and its incidence is increasing. Increases have been linked to modern dietary changes, stress, loneliness, sleep deprivation and endocrine dysfunction. Its diagnostic criteria span psychological and physical symptoms, including low mood, negative thinking and changes in sleep, appetite and weight. Additionally, there are strong relationships between depression and physical health, particularly heart disease. Key biomarkers identified to operate at the nexus of physical and mental health include cortisol, oxytocin, omega-3 fatty acids and leptin. While these show potential for novel therapeutic strategies, studies show inconsistent results, likely due to complex interactions between biopsychosocial variables and heterogeneous symptom subtypes. Structural equation modelling (SEM) is an analytical technique allowing examination of complex interactions between variables that predict important outcomes, such as illness. SEM has been extensively applied to coronary heart disease to identify points for interventions among numerous lifestyle and physical factors. As yet, similar, comprehensive models of depression are lacking. Developing and testing complex models including key biological and psychosocial variables may lead to improved interventions. Method: We quantified plasma cortisol, oxytocin, omega-3 fatty acid and leptin levels in 60 healthy participants and 60 meeting DSM-5 criteria for Major Depressive Disorder who were not receiving treatment. Participants completed detailed measures of psychopathology, stress, quality of life, psychosocial functioning, cognitive distortions and lifestyle data. Other physiological healthrelated measures included BMI, heat-rate, blood pressure and waist circumference. We employed correlational analyses and SEM using AMOS to test hypotheses about relationships between key physiological and psychological variables. Results: Several individual biomarkers showed distinct relationships with psychopathology, distress, quality of life, psychosocial functioning and cognition. In particular, cortisol levels were related to stress, psychopathology, perceived lack of social support and depressive cognitive distortions. Oxytocin levels were inversely associated with psychopathology and positively associated with perceived social support. Physiological health indices including heart rate and blood pressure were related both to specific psychopathological symptoms and to hormone levels. These relationships were further explored through SEM. Discussion: This study identified new information about links between several key biomarkers and specific symptoms in depression. Our application of SEM allows more complex understanding of the strength and direction of relationships between psychophysiological variables associated with depression. Further, large scale, studies are needed. Conclusion: This approach shows promise for increasing understanding of biological trajectories towards depression and ill health, which may potentially lead to targeted early interventions.
doi:10.1016/j.ijpsycho.2016.07.323
Background: Paranoia is a common trans-diagnostic psychological symptom involving thoughts and feelings of irrational mistrust, suspicion, persecution, threat or conspiracy. Paranoia occurs most commonly in psychotic disorders but also commonly occurs in other mental disorders and on a continuum in the general population. It is often associated with anxiety, hostility, hypervigilance and defensiveness. The psychophysiological processes involved in paranoia are not fully understood. Paranoia has been variously hypothesised to reflect disturbances in early perceptual processing, impaired emotional processing or regulation, impulsivity in terms of jumping to conclusions, or impairment in reasoning ability to assign meanings. Previous studies of paranoia have largely relied on self-report methodology. The high temporal resolution of event-related potentials (ERPS) allows the study of brain electrical activity during information-processing associated with early perceptual processing versus relatively more complex stages of inhibition and cognition. ERPs may thus be able to locate informationprocessing stages associated with anomalous brain activity in paranoia, to differentiate between explanations and improve understanding of this common symptom. Method: We examined ERPs in 60 participants, 20 with a diagnosed anxiety disorder, 20 with obsessive-compulsive disorder and 20 healthy controls. Paranoid ideation was assessed using the Brief Symptom Inventory (BSI). ERP components were measured during implicit and explicit attention tasks involving emotionally threatening and neutral stimuli. Hierarchical multiple regressions were performed. Results: Paranoid ideation showed correlations with amplitudes of multiple ERP components, however associations were strongest for the P3 component. In particular, P3 amplitude to emotionally threatening stimuli in the implicit attention task was inversely correlated with Paranoia. No sex differences were found. Discussion: The findings demonstrate that multiple processing stages are related to Paranoid Ideation, however there appears to be a greater involvement of cognitive processes reflected in the P3 component in Paranoid Ideation than those associated with other, earlier components. The results are consistent with previous observations that paranoid ideation may be particularly related to individuals’ attempts to interpret ambiguous (implicit) emotional arousal. Additionally they are consistent with findings of inverse correlations between psychotic symptoms and P3 amplitudes in several studies. Conclusion: The results have potential implications for cognitive models and interventions addressing paranoia.
doi:10.1016/j.ijpsycho.2016.07.324
405 Automatic categorization of brief changes of facial expression with fast periodic visual stimulation in EEG Bruno Rossion, Milena Dzhelyova University of Louvain, Louvain-la-Neuve, Belgium