Pain perception in people diagnosed with schizophrenia: where we are and where we are going

The insula: Leveraging cellular and systems-level research to better understand its roles in health and schizophrenia

Schizophrenia is a highly heterogeneous disorder characterized by a multitude of complex and seemingly non-overlapping symptoms. The insular cortex has gained increasing attention in neuroscience and psychiatry due to its involvement in a diverse range of fundamental human experiences and behaviors. This review article provides an overview of the insula's cellular and anatomical organization, functional and structural connectivity, and functional significance. Focusing on specific insula subregions and using knowledge gained from humans and preclinical studies of insular tracings in non-human primates, we review the literature and discuss the functional roles of each subregion, including in somatosensation, interoception, salience processing, emotional processing, and social cognition. Building from this foundation, we then extend these findings to discuss reported abnormalities of these functions in individuals with schizophrenia, implicating insular involvement in schizophrenia pathology. This review underscores the insula's vast role in the human experience and how abnormal insula structure and function could result in the wide-ranging symptoms observed in schizophrenia.

Evaluation of acute and chronic nociception in subchronically administered MK-801-induced rat model of schizophrenia

Patients diagnosed with schizophrenia have been reported to exhibit atypically low pain sensitivity and to vary in their experience of chronic pain. To the best of our knowledge, there has yet to be an animal study that provides information concerning the relationship between models of schizophrenia and pain. In the present study, we investigated several distinct nociceptive behaviors in a translational rat model of schizophrenia (0. 5 mg/kg MK-801, twice a day for 7 days followed by a 7-day washout period). The presence of the expected cognitive deficit was confirmed with novel object recognition (NOR) paradigm prior to nociception testing. MK-801-treated rats with lack of novelty interest in NOR testing showed: hyposensitivity to thermal and mechanical stimuli; short-term hypoalgesia followed by augmented hyperalgesia in response to formalin-induced spontaneous nociception and increased thermal and mechanical hyperalgesia in the complete Freund's adjuvant (CFA) induced chronic pain model. In conclusion, MK-801 induced antinociception effects for thermal stimuli in rats that were consistent with the decreased pain sensitivity observed in schizophrenia patients. Additionally, the amplified biphasic response exhibited by the MK-801 group in the formalin-induced spontaneous nociception test affirms the suitability of the test as a model of acute to delayed pain transition.

Emotion-focused group therapy among women with premenstrual dysphoric disorder: A randomized clinical trial

OBJECTIVE

Premenstrual Dysphoric Disorder (PMDD) contributes to couple burnout, reduced quality of life, sexual dysfunction, and social isolation. The present study aimed to investigate the effectiveness of emotion-focused group therapy (EFGT) in pain perception, self-compassion, sexual function, and couple burnout in women with PMDD. Method: Among married females with PMDD, 72 participants were selected and randomly assigned to experimental and waitlist control groups. EFGT was performed in 10 sessions for the subjects in the experimental groups. The McGill Pain Questionnaire, Self-Compassion Scale, Female Sexual Function Index and Couple Burnout Measure were used to collect data in the pre-test and post-test. To analyze the data, an analysis of covariance test was applied. Results: The findings demonstrated that EFGT was effective in pain perception (p < .001, η²=.80), self-compassion (p < .001, η²= .86), sexual function (p < .001, η²= .38), and couple burnout (p < .001, η²= .70). Participants of EFGT improved well, were satisfied with treatment, and had a good therapeutic relationship. Conclusion: Implementing EFGT increased the components of self-compassion and sexual function, and reduced the components of pain perception and couple burnout. It seems that EFGT could be effective in women with PMDD.

Proposing a causal pathway for health-related quality of life in people with psychotic disorders

This study aimed to establish independent predictors for health-related quality of life (HRQoL) in people with psychotic disorders, and the mediating role of global functioning in those relationships. Data for 1642 people collected as part of the second Australian National Survey of Psychosis were analyzed. The Assessment of Quality of Life (AQoL)-4D and the Personal and Social Performance scale were used for assessing HRQoL and global functioning respectively. The study commenced with a theoretical model comprised of 26 sociodemographic and clinical variables. A predictive model for HRQoL was built up using a purposeful selection strategy to arrive at a set of clinically meaningful, independent predictors. The mediating effect of global functioning was then assessed. Seven variables were found to have an independent effect on HRQoL: perception of loneliness, number of negative symptoms, use of psychotropic and anticholinergic medications, course of disorder, lifetime histories of chronic pain and cardiovascular disease and living arrangements at the time of the interview. All variables except perceived loneliness and chronic pain were partially mediated through global functioning. This final model explained 46% of the variance in HRQoL, with loneliness and number of negative symptoms the strongest predictors. Evidence in support of a credible causal pathway for HRQoL in people with psychotic disorders, mediated by global functioning was presented. The importance of the quality of social relationships was highlighted, and potential targets for improving the HRQoL of this population identified.

The aetiology of social deficits within mental health disorders: The role of the immune system and endogenous opioids

The American National Institute for Mental Health (NIMH) has put out a set of research goals that include a long-term plan to identify more reliable endogenous explanations for a wide variety of mental health disorders (Insel, 2013). In response to this, we have identified a major symptom that underlies multiple mental health disorders - social bonding dysfunction. We suggest that endogenous opioid abnormalities can lead to altered social bonding, which is a symptom of various mental health disorders, including depression, schizophrenia and ASD. This article first outlines how endogenous opioids play a role in social bonding. Then we show their association with the body's inflammation immune function, and review recent literature linking inflammation to mental health 'immunophenotypes'. We finish by explaining how these immunophenotypes may be caused by alterations in the endogenous opioid system. This is the first overview of the role of inflammation across multiple disorders where we provide a biochemical explanation for why immunophenotypes might exist across diagnoses. We propose a novel mechanism of how the immune system may be causing 'sickness-type' behaviours (fatigue, appetite change, social withdrawal and inhibited motivation) in those who have these immunophenotypes. We hope that this novel aetiology can be used as a basis for future research in mental health.