Insight in schizophrenia: From conceptualization to neuroscience

Laboratory of Clinical Neuroscience and Mental Health, Faculty of Medicine and Pharmacy, Casablanca, Morocco.
Psychiatry and Clinical Neurosciences (Impact Factor: 1.62). 04/2012; 66(3):167-79. DOI: 10.1111/j.1440-1819.2012.02325.x
Source: PubMed

ABSTRACT Lack of insight into illness is a prevalent and distinguishing feature of schizophrenia, which has a complex history and has been given a variety of definitions. Currently, insight is measured and treated as a multidimensional phenomenon, because it is believed to result from psychological, neuropsychological and organic factors. Thus, schizophrenia patients may display dramatic disorders including demoralization, depression and a higher risk of suicide, all of which are directly or indirectly related to a lack of insight into their illness, and make the treatment difficult. To improve the treatment of people with schizophrenia, it is thus crucial to advance research on insight into their illness. Insight is studied in a variety of ways. Studies may focus on the relationship between insight and psychopathology, may view behavioral outcomes or look discretely at the cognitive dysfunction versus anatomy level of insight. All have merit but they are dispersed across a wide body of literature and rarely are the findings integrated and synthesized in a meaningful way. The aim of this study was to synthesize findings across the large body of literature dealing with insight, to highlight its multidimensional nature, measurement, neuropsychology and social impact in schizophrenia. The extensive literature on the cognitive consequences of lack of insight and the contribution of neuroimaging techniques to elucidating neurological etiology of insight deficits, is also reviewed.

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Available from: Mounir Ouzir, Oct 14, 2014
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    ABSTRACT: Impaired insight in schizophrenia patients has been linked with prefrontal deficits. In this open-label study, we examined for potential insight facilitation effects of add-on tDCS (with anodal stimulation of left DLPFC and cathodal stimulation over left temporo-parietal junction) in schizophrenia patients (N = 21) with persistent auditory hallucinations despite adequate antipsychotic treatment. Following tDCS, there was a significant improvement in insight with concurrent significant reduction in auditory hallucination severity. Improvement in insight correlated significantly with improvement in severity of auditory hallucinations. These findings suggest improvement of insight with add-on tDCS in schizophrenia with persistent auditory hallucinations.
    Schizophrenia Research 06/2014; 156(1). DOI:10.1016/j.schres.2014.03.029 · 4.43 Impact Factor
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    ABSTRACT: Objectives Insight in psychiatry has been defined and conceptualized in a number of ways but none of them was found to be self-explanatory. There has been an exponential rise in studies of insight, in part accelerated by the availability of several psychometric scales for measuring insight. Lack of insight has been associated in schizophrenia with low treatment adherence, a high number of relapses, increased number of hospital admissions, and subsequently poorer psychological and cognitive functioning. For this reason, there is considerable interest in understanding the underlying neural mechanisms of insight, which may have important implications for the development of future insight-oriented neuro-psychiatric treatment. Neuroimaging may be considered an important technique to help understand the anatomical, functional and metabolic neurocircuitry underlying poor insight in schizophrenia. Growing neuroimaging research provides evidence for underlying brain impairment in insight deficits in schizophrenia. In order to expose a panoramic view to the readers, this article reviews the neuroimaging studies conducted to date, which have investigated the neural bases of insight in schizophrenia. Methods Electronic searches were performed in PubMed, PsycINFO, Sciencedirect and Web of Science databases, using the following keywords: Imaging; neuroimaging; Positron Emission Tomography (PET); spectroscopy; functional Magnetic Resonance Imaging (fMRI); structural Magnetic Resonance Imaging (MRI); Single Photon Emission Computed Tomography (SPECT); Voxel Based Morphometry (VBM); Diffusion Tensor Imaging (DTI); Computed Tomography (CT); Insight; schizophrenia; awareness of illness. Searches were also performed from the references of the systematic review articles on neurobiological correlates of insight in schizophrenia. Animal studies and single case reports were excluded. Twenty-five articles were selected for the present review. From these; 12 used structural MRI; 6 used VBM; 3 used fMRI; 2 used CT; 1 used DTI and 1 used VBM combined to DTI. Results The search showed that studies in this area were published recently and that the neuroanatomic substrate of insight in schizophrenia has not yet been consolidated. This inconsistency could arise from the complex nature of insight and the use of a variety of insight assessments. Most of the studies analyzed in this review used structural neuroimaging techniques to assess brain abnormalities associated with poor insight. The functional neuroanatomy of insight has only recently been investigated and to our knowledge, there are only 3 studies that have examined brain activity with fMRI in relation to insight in schizophrenia. Conclusion This review investigated the neural deficiencies underlying poor insight in schizophrenic patients. In spite of methodological differences among studies, results provide evidence of structural and functional brain abnormalities in frontal, parietal and temporal region related to insight deficits. Some studies have found a hemispheric asymmetry in relationship to poor in insight (the majority of brain abnormalities concern the right hemisphere). In addition, growing research indicated that the prefrontal cortex, particularly the dorsolateral prefrontal cortex, the anterior cingulated cortex, the insula, the precuneus and the cerebellum can also underlying insight in schizophrenia. It is interesting to mention that some authors have suggested that each dimension of insight can be specifically linked to certain brain structures. Taking together, data on the neuropsychological and neuroanatomical correlates of clinical insight suggested that lack of insight in schizophrenia could be conceived as a neurocognitive deficit, analogously to anosognosia in brain injury and dementia. On the contrary, to date, the neuroanatomical correlates of cognitive insight have been scarcely studied. Only two studies reported that Self-reflectiveness was positively related to gray matter volume of the right ventro-lateral prefrontal cortex, the BCIS composite index was positively correlated with total left hippocampal volume, and Self-certainty was inversely correlated with bilateral hippocampal volumes. However, it is important to note that neuroimaging research on cognitive insight in schizophrenia is in a preliminary, and the results on this are inconclusive. Further research is needed to better understand the causal relationships between brain abnormalities and degradation of insight in schizophrenia.
    Annales Médico-psychologiques revue psychiatrique 04/2014; 172:727–734. DOI:10.1016/j.amp.2013.07.012 · 0.15 Impact Factor
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    ABSTRACT: Previous studies have shown correlations between poor insight and neurocognitive impairment in schizophrenia. Deficit schizophrenia has been associated with worse cognitive functioning and poorer insight. This study aimed at investigating the relationship between insight dimensions (measured by Schedule for the Assessment of Insight-Expanded Version and its factors) and specific neurocognitive functions (assessed through a battery of neuropsychological tests) considering separately patients with deficit (n=29) and nondeficit schizophrenia (n=44), categorized according to the Schedule for the Deficit Syndrome. We found that working memory correlated positively and significantly with awareness of mental illness in both groups. In nondeficit group, awareness of mental illness correlated additionally with verbal fluency and attention. If confirmed by further studies, these results may have important consequences, such as the need of tailoring differently cognitive rehabilitation for each group.
    Schizophrenia Research 03/2013; DOI:10.1016/j.schres.2013.02.041 · 4.43 Impact Factor