Neurobiological underpinnings of insight deficits in schizophrenia

Do psychiatric registries include all persons with schizophrenia in the general population? A population-based longitudinal study

BACKGROUND

Psychiatric hospitalization registries are utilized to investigate the incidence and prevalence of schizophrenia for both research and administrative purposes. The assumption behind this is that most individuals with schizophrenia will be hospitalized at least once in their life-time.

METHOD

In an epidemiological survey conducted in the 1980s, a population-based sample (n = 4914) of Israel-born individuals then aged 25-34 were screened in the community, and 29 (0.6%) were subsequently diagnosed by psychiatrists using SADS/RDC criteria. Twenty four years later we linked data from the epidemiological survey with the Israeli National Psychiatric Hospitalization Registry.

RESULTS

Twenty seven of the 29 individuals (93%) diagnosed with schizophrenia in the survey were identified in the hospitalization registry with the same diagnosis. Fifty-two (1.0%) participants not diagnosed during the survey with schizophrenia were identified in the psychiatric hospitalization registry 24 years later with schizophrenia. The majority of them were diagnosed with other psychiatric disorders in the survey. If all diagnoses of schizophrenia are accepted at face value, the lifetime prevalence rate would be 1.8% for this cohort.

CONCLUSION

The overwhelming majority of individuals diagnosed with schizophrenia at ages 25-34 in an epidemiological survey were present in the Psychiatric Hospitalization Registry. However, the assessment of life-time rates of schizophrenia at these ages is problematic because some future cases are asymptomatic, others have premorbid non-psychotic disorders, while in others it is difficult to differentiate between affective disorders and schizophrenia. Availability of psychiatric services and hospitalization policy must be considered when generalizing these findings to other countries.

Gray matter volume deficits and correlation with insight and negative symptoms in first-psychotic-episode subjects

OBJECTIVE

To determine brain areas reduced in first episode of psychotic subjects and its association with lack of insight and negative symptoms.

METHOD

Twenty-one drug naive first-episode subjects and 20 controls underwent a structural MRI scan and were clinically assessed. Optimized voxel-based-morphometry analysis (VBM) was implemented to find between-group differences and correlations between GM volume and: (i) lack of insight and (ii) negative symptoms.

RESULTS

Patients showed GM reduction in prefrontal and left temporal areas. A significant correlation was found between insight and GM volume in the cerebellum (corrected P = 0.01), inferior temporal gyrus (corrected P = 0.022), medial superior frontal gyrus (corrected P < 0.001), and inferior frontal gyrus (corrected P = 0.012), as the insight decreased, the volume decreased. Negative symptoms correlated with decreased GM volume at cerebellum (corrected P = 0.037) and frontal inferior regions (corrected P < 0.001), the more negative symptoms, the less volume.

CONCLUSION

Our findings support an association between prefrontal, temporal, and cerebellar deficits and lack of insight in schizophrenia and confirm previous findings of GM deficits in patients since the first episode of psychosis.

White matter integrity and lack of insight in schizophrenia and schizoaffective disorder

OBJECTIVE

Poor insight into illness is commonly associated with schizophrenia and has implications for the clinical outcome of the disease. A better understanding of the neurobiology of these insight deficits may help the development of new treatments targeting insight. Despite the importance of this issue, the neural correlates of insight deficits in schizophrenia remain poorly understood.

METHOD

Thirty-six individuals diagnosed with schizophrenia or schizoaffective disorder underwent diffusion tensor imaging (DTI). The subjects were assessed on two dimensions of insight (symptom awareness and attribution of symptoms) using the Scale to Assess Unawareness of Mental Disorder (SUMD). Level of psychosis was assessed with the Positive and Negative Syndrome Scale (PANSS).

RESULTS

White matter abnormalities in the right superior frontal gyrus, left middle frontal gyrus, bilateral parahippocampal gyrus, adjacent to the right caudate head, right thalamus, left insula, left lentiform nucleus, left fusiform gyrus, bilateral posterior cingulate, left anterior cingulate, right cingulate gyrus, left lingual gyrus, and bilateral claustrum were associated with symptom unawareness. Misattribution of symptoms was related to deficits in the white matter adjacent to the right lentiform nucleus, left middle temporal gyrus, and the right precuneus.

CONCLUSIONS

Impaired insight in schizophrenia implicates a complex neural circuitry: white matter deficits in fronto-temporo brain regions are linked to symptom unawareness; compromised temporal and parietal white matter regions are involved in the misattribution of symptoms. These findings suggest the multidimensional construct of insight has multiple neural determinants.

Trait and state attributes of insight in first episodes of early-onset schizophrenia and other psychoses: a 2-year longitudinal study

BACKGROUND

Increasing evidence supports the important role of illness state and individual characteristics in insight.

METHODS

Insight, as measured with the Scale to Assess Unawareness of Mental Disorder, over the first 2 years of early-onset first-episode psychosis and its correlations with clinical, socio-demographic, cognitive, and structural brain variables are studied.

RESULTS

(1) insight at 2 years is poorer in schizophrenia spectrum disorders (SSDs) than in subjects with other psychoses; (2) the more severe the psychosis, the worse the insight. In SSD, depressive symptoms, poorer baseline executive functioning, lower IQ, longer duration of untreated psychosis (DUP), and poorer premorbid infancy adjustment are associated with poorer insight; frontal and parietal gray matter (GM) reductions at baseline correlate with worse insight into having psychotic symptoms at 2 years; (3) insight into having a mental disorder (Scale to Assess Unawareness of Mental Disorder [SUMD]1) at 1 year, DUP, and baseline IQ are the most consistent variables explaining different aspects of insight at 2 years in SSD patients. IQ and SUMD1 at 1 year, together with left frontal and parietal GM volumes, explain 80% of the variance of insight into having specific psychotic symptoms in SSD patients (adjusted R(2) = 0.795, F = 15.576, P < .001).

CONCLUSION

Insight is a complex phenomenon that depends both on severity of psychopathology and also on disease and subject characteristics, such as past adjustment, IQ, DUP, cognitive functioning, frontal and parietal GM volumes, and age, gender, and ethnicity.

Correlates, change and 'state or trait' properties of insight in schizophrenia

BACKGROUND

The associations of insight into illness and clinical and socio-demographic variables in schizophrenia have been examined, yet little attention has been given to premorbid functioning, insight change and outcomes.

OBJECTIVES

We examined these associations in a large cohort of recent onset schizophrenia spectrum disorder patients.

METHODS

This was a prospective 6-month, open-label, multicentre, phase IV trial in 303 subjects with recent onset (<or=2 years) schizophrenia treated with risperidone long-acting injection (RLAI). Insight (Schedule for the Assessment of Insight - Expanded), treatment efficacy (Positive and Negative Syndrome Scale, Clinical Global Impression) and quality of life (Short Form-36) were assessed at baseline and after 2, 4 and 6 months. The Premorbid Adjustment Scale was administered at baseline.

RESULTS

Insight was positively associated with better premorbid functioning, more education and schizoaffective disorder versus schizophrenia. Insight improved modestly, but significantly throughout treatment, particularly illness beliefs. Baseline insight was negatively correlated with quality of life and positive symptoms and positively correlated with anxiety/depression. It was not significantly associated with change in symptom severity or time in trial, but was positively associated with age.

CONCLUSIONS

Insight, at least in this stable, comparatively high-insight sample, improved during treatment but this is not closely related to improvement in psychotic symptoms. Insight appears to have trait-like qualities demonstrated by association with premorbid factors. While insight is generally a favorable attribute and is associated with fewer psychotic symptoms, it is also associated with increased depression and lower perceived quality of life. Some components of insight are more amenable to improvement; particularly the ability to adopt less fixed illness attributions.

Beyond dopamine: functional MRI predictors of responsiveness to cognitive behaviour therapy for psychosis

Despite the favourable effects of antipsychotics on positive symptoms of schizophrenia, many patients continue to suffer from distressing symptoms. Additional benefits of cognitive behaviour therapy for psychosis (CBTp) have been reported for approximately 50% of such patients. Given the role of left hemisphere-based language processes in responsiveness to CBT for depression, and language pathway abnormalities in psychosis, this study examined whether pre-therapy brain activity during a verbal monitoring task predicts CBTp responsiveness in schizophrenia. Fifty-two outpatients, stable on antipsychotics with at least one persistent distressing positive symptom and wishing to receive CBTp adjunctive to their treatment-as-usual, and 20 healthy participants underwent fMRI during monitoring of self- and externally-generated (normal and distorted) speech. Subsequently, 26 patients received CBTp for 6–8 months adjunctive to their treatment-as-usual (CBTp + TAU, 20 completers), and 26 continued with their treatment-as-usual (TAU-alone, 18 completers). Symptoms were assessed (blindly) at entry and follow-up. The CBTp + TAU and TAU-alone groups had comparable demographic characteristics, performance and baseline symptoms. Only the CBTp + TAU group showed improved symptoms at follow-up. CBTp responsiveness was associated with (i) greater left inferior frontal gyrus (IFG) activity during accurate monitoring, especially of own voice, (ii) less inferior parietal deactivation with own, relative to others’, voice, and (iii) less medial prefrontal deactivation and greater thalamic and precuneus activation during monitoring of distorted, relative to undistorted, voices. CBTp + TAU patients, on average, displayed left IFG and thalamic hypo-activation (<healthy participants). The findings implicate language processing (IFG), attention (thalamus), insight and self-awareness (medial prefrontal and parietal cortices) in CBTp responsiveness in schizophrenia.

Help-negation and suicidal ideation: the role of depression, anxiety and hopelessness

Help-negation is expressed behaviorally by the refusal or avoidance of available help and cognitively by the inverse relationship between self-reported symptoms of psychological distress and help-seeking intentions. The current study examined the association between suicidal ideation and intentions to seek help from friends, family and professional mental health sources in a sample of 302 Australian university students. Participants were 77.5% female and aged from 18-25 years old, with 85.4% aged 21 years or younger. Higher levels of suicidal ideation were related to lower help-seeking intentions for family, friends, and professional mental health care, and higher intentions to seek help from no one. Moderation effects indicated that higher levels of depressive symptoms strengthen the help-negating effect of suicidal ideation for seeking help from friends, family and no one. The results indicate that, even at subclinical levels, suicidal ideation impedes the cognitive help-seeking process at the decision making stage. The results also highlight the importance of improving our understanding of why young people become reluctant to seek help as their levels of suicidal ideation and depressive symptoms increase. Raising awareness that the experience of suicidal ideation and depressive symptoms can promote intentions to avoid help might reduce the help-negation effect when symptoms are first recognized.

Remission in patients with first-episode schizophrenia receiving assured antipsychotic medication: a study with risperidone long-acting injection

Recently proposed criteria for remission by a 'Remission in Schizophrenia Working Group' have generated considerable interest. We assessed rates, predictors, and correlates of remission in a sample of patients with first-episode schizophrenia treated with injectable, long-acting risperidone. This allowed us to examine remission among patients known to be receiving medication. This was a single-site open-label study in which 50 newly diagnosed cases of schizophreniform disorder or schizophrenia aged 16 to 43 years were treated with injectable, long-acting risperidone 25-50 mg every 2 weeks for 2 years. Remission, according to Remission in Schizophrenia Working Group criteria, was achieved in 64% of the patients. Of those achieving remission, 97% maintained this status until study completion. Remission was associated with greater improvements in other symptom domains, insight, and social and occupational functioning. Patients in remission received lower doses of antipsychotic medication, had fewer extrapyramidal symptoms, and a more favorable attitude toward medication. The results of this open-label study suggest that a majority of first-episode patients who receive long-acting injectable antipsychotic medication may achieve sustained remission. Double-blind-controlled studies using long-acting injectable antipsychotics in early psychosis are warranted to further test this.

Neurological basis of poor insight in psychosis: a voxel-based MRI study

BACKGROUND

As a reflection of poor insight, people with schizophrenia often disagree with carers and clinicians about whether (a) their experiences are abnormal, (b) they are mentally ill, and (c) they need treatment.

METHODS

This study used voxel-based morphometry to identify the associations between total and regional grey matter volumes and self-reported and observer-rated insight in 52 patients with schizophrenia or schizoaffective disorder. Thirty healthy participants were also studied.

RESULTS

There were positive associations in patients between (i) the ability to recognise experiences as abnormal and the total and right superior temporal gyrus grey matter volumes, (ii), awareness of problems ('something wrong') and the left precuneus grey matter volume and (iii) awareness of symptoms and attributing them to illness and grey matter volumes in the left superior-middle temporal gyrus and the right inferior temporal and lateral parietal gyri. The 'recognition of the need for medication' dimension did not correlate with total or any regional grey matter volumes. Relative to controls, patients had less total and regional grey matter volumes in the thalamus and middle occipital and superior temporal gyri.

CONCLUSIONS

Lower grey matter volumes in the temporal and parietal regions that have been implicated in self-monitoring, working memory and access to internal mental states are associated with poor insight on certain dimensions in psychosis.

Predictors of long-term outcome in schizophrenia

PURPOSE OF REVIEW

Further clarification of factors predicting the outcome in schizophrenia is needed. The present review examines recent research into some of these predictors, focusing on insight, duration of untreated psychosis, cognition and early treatment response. It also addresses the need for standard outcome measures.

RECENT FINDINGS

There is good evidence that poor insight predicts poor outcome, although perhaps not simply as a consequence of poor compliance. Further support is provided for a link between duration of untreated psychosis and long-term outcome. The relationship between cognition and outcome is complex, with specific cognitive deficits apparently predicting particular outcome domains. Early treatment response is closely related to long-term outcome. Outcome studies may be flawed by sample selection bias, and a lack of standardized outcome measures.

SUMMARY

Several predictors are potentially modifiable, indicating that they should be targets for therapeutic intervention. More carefully designed studies are needed. Recently proposed criteria for remission are helpful, and should facilitate cross-sample comparisons.