Hypnosis and suggestion as interventions for functional neurological disorder: A systematic review

OBJECTIVE

Functional neurological disorder (FND) involves the presence of neurological symptoms that cannot be explained by neurological disease. FND has long been linked to hypnosis and suggestion, both of which have been used as treatments. Given ongoing interest, this review examined evidence for the efficacy of hypnosis and suggestion as treatment interventions for FND.

METHOD

A systematic search of bibliographic databases was conducted to identify group studies published over the last hundred years. No restrictions were placed on study design, language, or clinical setting. Two reviewers independently assessed papers for inclusion, extracted data, and rated study quality.

RESULTS

The search identified 35 studies, including 5 randomised controlled trials, 2 non-randomised trials, and 28 pre-post studies. Of 1584 patients receiving either intervention, 1379 (87%) showed significant improvements, including many who demonstrated resolution of their symptoms in the short-term. Given the heterogeneity of interventions and limitations in study quality overall, more formal quantitative synthesis was not possible.

CONCLUSIONS

The findings highlight longstanding and ongoing interest in using hypnosis and suggestion as interventions for FND. While the findings appear promising, limitations in the evidence base, reflecting limitations in FND research more broadly, prevent definitive recommendations. Further research seems warranted given these supportive findings.

An observer-rated strategy for differentiating schizophrenic and manic states in inpatient settings

OBJECTIVES

Differentiating schizophrenia from mania in acutely psychotic patients can be difficult, but is important in determining immediate and subsequent management. Such differentiation is generally addressed by clinical interviews, but an observational approach may assist. This paper therefore describes the development of a relevant observational measure.

METHODS

We developed a provisional list of 49 items (weighting features with suggested specificity to schizophrenia and mania) for independent completion by two nurses and judged its ability to predict diagnosis provided by consultant psychiatrists.

RESULTS

Eighty-seven psychotic patients were recruited, and 173 completed data sets were analysed. We refined the item set to two sets of 10 items that best-differentiated schizophrenia from mania and vice versa. Optimal differentiation was achieved with a score of at least 7 on both the schizophrenia and mania item sets. Difference scores (i.e. schizophrenia items affirmed minus mania items affirmed) were also generated, with a difference score of +1 (i.e. one or more schizophrenia items being affirmed than mania items) showing optimal differentiation (sensitivity 0.67, specificity 0.82) between the two conditions. Evaluating all potential difference scores, we demonstrated that, as difference scores increased, diagnostic accuracy in identifying each condition was very high.

CONCLUSION

Analyses allow the properties of an observational measure (the 20-item Sydney Psychosis Observation Tool) to be described. While a single cut-off difference score was derived with acceptable discriminatory ability, we also established the capacity of varying difference scores to assign both schizophrenia and mania diagnoses with high accuracy.

Apathy and depression in mild cognitive impairment: distinct longitudinal trajectories and clinical outcomes

OBJECTIVES

Apathy is a common symptom in mild cognitive impairment (MCI) and may predict progression to dementia. Little research, however, has investigated the longitudinal trajectory of apathy in patients with MCI or controlled for depression, which can mimic apathy, when examining its clinical correlates. The current study sought to address these issues.

DESIGN

A prospective longitudinal study was conducted over 3 years.

SETTING

Nine memory clinics around Australia.

PARTICIPANTS

One hundred and eighty-five patients with MCI at baseline.

MEASUREMENTS

Measures of cognition, function, neuropsychiatric symptoms, caregiver burden, and medication use were completed annually with additional assessments at 3 and 6 months. Patients were also assessed for dementia by expert clinicians at these time points.

RESULTS

Of 164 patients who completed measures of neuropsychiatric symptoms, 59 (36.0%) had apathy and 61 (37.2%) had depression. The proportion affected by apathy and overall apathy scores increased over time, in contrast to measures of depression, which remained relatively stable. Apathy was associated with incident dementia and worse cognition, function, neuropsychiatric symptoms, and caregiver burden independent of both depression and incident dementia. Depression was associated with worse function, albeit to lesser degree than apathy, and neuropsychiatric symptoms.

CONCLUSIONS

Apathy increases in MCI and is associated with worse clinical outcomes. These findings provide further evidence for apathy as a marker of clinical decline in older people and poorer outcomes across neurocognitive disorders.

Apathy and Depression in Huntington's Disease: Distinct Longitudinal Trajectories and Clinical Correlates

OBJECTIVE

Huntington's disease (HD) is an autosomal-dominant neurodegenerative disease resulting in motor disturbances, dementia, and psychiatric symptoms. Apathy is a common manifestation and rated as one of the most impactful by patients and caregivers. It can often be difficult to distinguish from depression because of shared features and frequent overlap. This study examined the longitudinal trajectories and clinical correlates of apathy and depression.

METHODS

Data were drawn from the Cooperative Huntington Observational Research Trial, a prospective, multicenter observational study that recruited 1,082 patients with HD. Measures of cognition, function, neuropsychiatric symptoms, motor function, and medication use were completed annually over 5 years.

RESULTS

Overall, 423 patients (39%) showed evidence of apathy at study baseline, and both the prevalence and overall severity of apathy increased over time. Depression, by contrast, affected a similar proportion at baseline, although levels remained relatively stable over the study. Apathy was associated with worse cognition, function, neuropsychiatric symptoms, and motor symptoms. Depression was associated with worse neuropsychiatric symptoms, suicidal ideation, and independence but not other outcomes after control for other variables.

CONCLUSIONS

Apathy in HD increased over time and was associated with worse clinical outcomes. These associations were independent of depression and other clinical variables. The findings highlight the need to distinguish between apathy and depression given their distinct implications for prognosis and management.

Calibrating violence risk assessments for uncertainty

Psychiatrists and other mental health clinicians are often tasked with assessing patients' risk of violence. Approaches to this vary and include both unstructured (based on individual clinicians' judgement) and structured methods (based on formalised scoring and algorithms with varying scope for clinicians' judgement). The end result is usually a categorisation of risk, which may, in turn, reference a probability estimate of violence over a certain time period. Research over recent decades has made considerable improvements in refining structured approaches and categorising patients' risk classifications at a group level. The ability, however, to apply these findings clinically to predict the outcomes of individual patients remains contested. In this article, we review methods of assessing violence risk and empirical findings on their predictive validity. We note, in particular, limitations in calibration (accuracy at predicting absolute risk) as distinct from discrimination (accuracy at separating patients by outcome). We also consider clinical applications of these findings, including challenges applying statistics to individual patients, and broader conceptual issues in distinguishing risk and uncertainty. Based on this, we argue that there remain significant limits to assessing violence risk for individuals and that this requires careful consideration in clinical and legal contexts.

Presentations to the emergency department with self-harm or suicidal behaviours: A role for digital mental health services?

Emergency Department (ED) is an important site for assessing people presenting with self-harm or suicidal behaviors. Digital mental health services (DMHS) offer evidence-based interventions for mental health issues, but are often under-utilised, and information about them is rarely provided in ED. This feasibility study explored whether offering information about a DMHS to individuals presenting to ED with self-harm/suicidal behaviors resulted in self-enrolment in DMHS interventions for anxiety, depression and/or chronic pain.

METHODS

all individuals aged 18+ presenting with self-harm/suicidal behaviors to a metropolitan ED were screened for symptoms of anxiety, depression and/or chronic pain. Those with these symptoms were invited to participate in a study investigating enrolment with a DMHS. Study participants were provided with information about DMHS and followed up at one month.

RESULTS

260 individuals presented with self-harm/suicidal behaviors over the 6-month study period. Many reported low mood (73.5%, n = 191) anxiety (67.2%, n = 174) and/or chronic pain (18.5%, n = 48). Half of those eligible for DMHS agreed at point of ED discharge to be contacted about participation in the DMHS study (51.4%, n = 108). One-third of these participated in the study (35.2%, n = 38). Rates of past-month high-risk SB (65.8%, n = 25), depression (92.1%, n = 35), anxiety (78.9%, n = 30) and chronic pain (57.9%, n = 22) were very high. Of these, 39.5% (n = 15) self-enrolled with the DMHS; almost all (80.0%, n = 13) engaged with an online intervention.

CONCLUSIONS

A subset of people presenting to emergency department with suicidal behaviors will engage with DMHS. Better understanding is needed of factors contributing to uptake of DMHS in this group.

Distinguishing apathy and depression in dementia: A longitudinal study

OBJECTIVES

Apathy is a common symptom in dementia, though can be difficult to distinguish from depression due to shared features and frequent co-occurrence. As such, a significant limitation of much previous research on apathy is the failure to control for depression. The current study sought to address this by examining the trajectory and clinical correlates of apathy after controlling for depression.

METHODS

Seven hundred and seventy-nine patients with dementia were recruited from nine memory clinics around Australia. Measures of dementia severity, cognition, functional ability, neuropsychiatric symptoms, caregiver burden and medication use were completed at baseline and at regular intervals over a 3-year period. Driving and institutionalisation data were obtained throughout the study. Mortality data were obtained from state registries 8 years after baseline.

RESULTS

Of the 662 patients with completed measures of neuropsychiatric symptoms, 342 (51.7%) had apathy and 332 (50.2%) had depression at baseline, while 212 (32.0%) had both. Whereas apathy increased over time, depression remained relatively stable. Apathy, but not depression, was associated with greater dementia severity, poorer cognition and function, driving cessation and mortality. Both apathy and depression were associated with greater neuropsychiatric symptoms, psychosis, caregiver burden and institutionalisation.

CONCLUSIONS

Apathy increases over the course of dementia and is associated with worse clinical outcomes independent of depression. Distinguishing apathy and depression appears important given their different implications for prognosis and management.

Pseudodementia, pseudo-pseudodementia, and pseudodepression

Dementia has a wide range of reversible causes. Well known among these is depression, though other psychiatric disorders can also impair cognition and give the appearance of neurodegenerative disease. This phenomenon has been known historically as "pseudodementia." Although this topic attracted significant interest in the 1980s and 1990s, research on the topic has waned. In this paper, we consider reasons for this decline, including objections to the term itself and controversy about its distinctness from organic dementia. We discuss limitations in the arguments put forward and existing research, which, crucially, does not support inevitable progression. We also discuss other neglected masquerades, such as of pseudodementia itself ("pseudo-pseudodementia") and depression ("pseudodepression"). Based on this reappraisal, we argue that these terms, while not replacing modern diagnostic criteria, remain relevant as they highlight unique groups of patients, potential misdiagnosis, and important, but neglected, areas of research.

Dementia and caregiver burden: A three-year longitudinal study

OBJECTIVES

Dementia, with its progressive cognitive and functional decline and associated neuropsychiatric symptoms, places a large burden on caregivers. While frequently studied, longitudinal findings about the overall trajectory of burden are mixed. The study sought to characterize caregiver burden over a 3-year period and identify predictors of this burden.

METHODS

Seven-hundred-and-eighty-one patients with dementia were recruited from nine memory clinics around Australia. Measures of caregiver burden, cognition, function, and neuropsychiatric symptoms were completed with patients and their caregivers at regular intervals over a 3-year period. Patients' level of services and medication use were also recorded.

RESULTS

Of the 720 patients with measures of caregiver burden at baseline, 47.4% of caregivers had clinically significant levels of burden. This proportion increased over time, with 56.8% affected at 3 years. Overall levels of burden increased for caregivers of patients without services, though did not change for caregivers of patients receiving services or residential care after controlling for other variables. Patient characteristics-including greater neuropsychiatric symptoms, lower functional ability, fewer medications, lack of driving ability-and female sex of caregivers were associated with greater burden.

CONCLUSIONS

High levels of caregiver burden are present in a large proportion of caregivers of people with dementia and this increases over time for those without services. Clinical characteristics of patients (including neuropsychiatric symptoms, function, overall health, driving status), level of services, and caregiver sex appear to be the best predictors of this burden. These characteristics may help identify caregivers at greater risk of burden to target for intervention.

Psychosis and longitudinal outcomes in Huntington disease: the COHORT Study

OBJECTIVE

Huntington disease (HD) is an autosomal dominant neurodegenerative disease involving motor disturbances, cognitive decline and psychiatric symptoms. Psychotic symptoms occur in a significant proportion of patients. We sought to characterise the clinical outcomes of this group of patients.

METHODS

Data were drawn from the Cooperative Huntington Observational Research Trial, a prospective, multi-centre observational study. 1082 patients with HD were recruited. Measures of cognition, function, behavioural disturbance and motor function were completed annually over 5 years.

RESULTS

Overall, 190 patients (17.6%) displayed psychotic symptoms. These patients demonstrated worse cognition, function and behavioural disturbances than patients without psychosis over time. Patients with psychosis also demonstrated lower levels of chorea than patients without psychosis, despite adjusting for concurrent antipsychotic and tetrabenazine use.

CONCLUSIONS

Psychosis in HD is associated with poorer outcomes in cognition, function and behavioural symptoms. Patients with psychotic symptoms may also have less chorea. Altogether, the findings suggest patients with psychosis have a distinct clinical course.

Mild Cognitive Impairment and Caregiver Burden: A 3-Year-Longitudinal Study

OBJECTIVES

Mild cognitive impairment (MCI) is common, affecting 10%-35% of people over 65, and poses unique challenges for patients and their caregivers. Comparatively little research has examined caregiver burden in this population, with longitudinal research, in particular, lacking. We examined caregiver burden in a sample of people with MCI over 3 years.

DESIGN

Three-year observational study.

SETTING

Nine memory clinics in Australia.

PARTICIPANTS

One-hundred-and-eighty-five people with MCI and their caregivers.

MEASUREMENTS

Measures of caregiver burden, cognition, function, neuropsychiatric symptoms, driving status, and medication use were completed with patients and their caregivers at regular intervals over a 3-year period.

RESULTS

Between 21.1% and 29.5% of caregivers reported a clinically significant level of burden over the study. Patients' higher levels of neuropsychiatric symptoms, lower functional ability, and lack of driving ability, and caregivers' employment were associated with greater caregiver burden over time. Caregiver burden did not increase over time when controlling for patient and caregiver characteristics.

CONCLUSIONS

High levels of caregiver burden are present in a significant proportion of caregivers of people with MCI. Clinical characteristics of patients - including severity of neuropsychiatric symptoms and functional impairment - and the employment status of caregivers predict burden. Such characteristics may help identify caregivers at greater risk of burden to target for intervention.

Longitudinal outcomes of patients with pseudodementia: a systematic review

Depression and a number of other psychiatric conditions can impair cognition and give the appearance of neurodegenerative disease. Collectively, this group of disorders is known as 'pseudodementia' and are important to identify given their potential reversibility with treatment. Despite considerable interest historically, the longitudinal outcomes of patients with pseudodementia remain unclear. We conducted a systematic review of longitudinal studies of pseudodementia. Bibliographic databases were searched using a wide range of search terms. Two reviewers independently assessed papers for inclusion, rated study quality, and extracted data. The search identified 18 studies with follow-up varying from several weeks to 18 years. Overall, 284 patients were studied, including 238 patients with depression, 18 with conversion disorder, 14 with psychosis, and 11 with bipolar disorder. Irrespective of diagnosis, 33% developed irreversible dementia at follow-up, 53% no longer met criteria for dementia, and 15% were lost to follow-up. Considerable variability was identified, with younger age at baseline, but not follow-up duration, associated with better outcomes. ECT and pharmacological interventions were also reported to be beneficial, though findings were limited by the poor quality of the studies. Overall, the findings suggest that pseudodementia may confer an increased risk of irreversible dementia in older patients. The findings also indicate, however, that a significant proportion improve, while many remain burdened with their psychiatric condition, independent of organic dementia. The findings support the clinical value of the construct and the need for its re-examination in light of developments in neuroimaging, genomics, other investigative tools, and trial methodology.

Non-pharmacological interventions for Lewy body dementia: a systematic review

Lewy body dementia (consisting of dementia with Lewy bodies and Parkinson's disease dementia) is a common neurodegenerative disease characterised by visual hallucinations, fluctuating attention, motor disturbances, falls, and sensitivity to antipsychotics. This combination of features presents challenges for pharmacological management. Given this, we sought to review evidence for non-pharmacological interventions with patients with Lewy body dementia and their carers. Bibliographic databases were searched using a wide range of search terms and no restrictions were placed on study design, language, or clinical setting. Two reviewers independently assessed papers for inclusion, rated study quality, and extracted data. The search identified 21 studies including two randomised controlled trials with available subgroup data, seven case series, and 12 case studies. Most studies reported beneficial effects of the interventions used, though the only sizeable study was on dysphagia, showing a benefit of honey-thickened liquids. Given the heterogeneity of interventions and poor quality of the studies overall, no quantitative synthesis was possible. Overall, identified studies suggested possible benefits of non-pharmacological interventions in Lewy body dementia, but the small sample sizes and low quality of studies mean no definite recommendations can be offered. Our findings underscore the clear and urgent need for future research on this topic.

Proportional hazard model estimation under dependent censoring using copulas and penalized likelihood

This paper considers Cox proportional hazard models estimation under informative right censored data using maximum penalized likelihood, where dependence between censoring and event times are modelled by a copula function and a roughness penalty function is used to restrain the baseline hazard as a smooth function. Since the baseline hazard is nonnegative, we propose a special algorithm where each iteration involves updating regression coefficients by the Newton algorithm and baseline hazard by the multiplicative iterative algorithm. The asymptotic properties for both regression coefficients and baseline hazard estimates are developed. The simulation study investigates the performance of our method and also compares it with an existing maximum likelihood method. We apply the proposed method to a dementia patients dataset.

Mild Cognitive Impairment and Driving Cessation: A 3-Year Longitudinal Study

BACKGROUND/AIMS

Driving cessation is associated with significant morbidity in older people. People with mild cognitive impairment (MCI) may be at particular risk of this. Very little research has examined driving in this population. Given this, we sought to identify predictors of driving cessation in people with MCI.

METHODS

One hundred and eighty-five people with MCI were recruited from 9 memory clinics around Australia. People with MCI and their carers reported their driving status and completed measures of cognition, function, neuropsychiatric symptoms, and medication use at regular intervals over a 3-year period.

RESULTS

Of the 144 people still driving at baseline, 50 (27.0%) stopped driving during the study. Older age, greater cognitive and functional impairment, and greater decline in cognition and function at 6 months predicted subsequent driving cessation. Twenty-nine of the 50 people (58%) who stopped driving were diagnosed with dementia during the study; all except one of whom ceased driving after their dementia diagnosis.

CONCLUSION

A significant proportion of people diagnosed with MCI stop driving over the following 3 years. This cannot be entirely attributed to developing dementia. Easily assessable characteristics - such as age, cognition, and function - and changes in these measures over 6 months predict driving cessation.

Hypnotic clever hands: Agency and automatic responding

The Clever Hands task (Wegner, Fuller, & Sparrow, 2003) is a behavioral illusion in which participants make responses to a trivia quiz for which they have no sense of agency. Sixty high hypnotizable participants completed two versions of the Clever Hands task. Quiz One was a replication of the original study. Quiz Two was a hypnotic adaptation using three suggestions that were based on clinical disruptions to the sense of agency. The suggestions were for: random responding, thought insertion, and alien control. These suggestions led to differences in accuracy (action production) and estimates of accuracy (action projection). Specifically, whereas the random responding suggestion had little effect, the two clinically based suggestions had opposite impacts on action production: the thought insertion suggestion led to an increase in the rate of correct responses (although participants still believed they were responding randomly); while the alien control suggestion led to a reduction in the rate of correct answers and a pattern of results that more closely approximated randomness. Contrary to theoretical accounts that claim that hypnosis affects executive monitoring rather than executive control, this result indicates that specific hypnotic suggestions can also influence the implicit processes involved in action production. (PsycINFO Database Record

Psychosis and Clinical Outcomes in Alzheimer Disease: A Longitudinal Study

OBJECTIVE

Psychotic symptoms are a common feature in Alzheimer disease (AD), occurring in approximately 40% of patients. These symptoms are associated with worse clinical outcomes. Comparatively little research, however, has distinguished delusions and hallucinations, which may have distinct clinical, neuropathological, and genetic correlates. To address this, the current study examined the clinical outcomes associated with delusions and hallucinations in AD.

DESIGN

Three-year observational study.

SETTING

Nine memory clinics in Australia.

PARTICIPANTS

A total of 445 patients with AD.

MEASUREMENTS

Measures of neuropsychiatric symptoms, dementia severity, cognition, function, caregiver burden, and medication use were completed annually for 3 years with additional assessments at 3 months and 6 months in the first year. Mortality data were obtained from state registries approximately 5 years after the study.

RESULTS

Of 445 patients, 102 (22.9%) developed only delusions, 39 (8.8%) developed only hallucinations, and 84 (18.9%) developed both symptoms. Delusions and hallucinations were both associated with greater dementia severity, poorer cognition and function, higher levels of other neuropsychiatric symptoms, and greater caregiver burden. The presence of both symptoms was associated with worse outcomes than only one of these symptoms. Delusions, both by themselves and in combination with hallucinations, predicted institutionalization. Antipsychotic medication use predicted mortality.

CONCLUSIONS

Delusions and hallucinations independently and in combination are associated with poor clinical outcomes. The findings highlight the challenges managing these patients, particularly given the high levels of caregiver burden associated with psychotic symptoms and the likely mortality arising from antipsychotic medication.

Screening for Dementia in Primary Care: A Comparison of the GPCOG and the MMSE

BACKGROUND/AIMS

The General Practitioner Assessment of Cognition (GPCOG) is a brief cognitive test. This study compared the GPCOG to the Mini-Mental State Examination (MMSE), the most widely used test, in terms of their ability to detect likely dementia in primary care.

METHODS

General practitioners across three states in Australia recruited 2,028 elderly patients from the community. A research nurse administered the GPCOG and the MMSE, as well as the Cambridge Examination for Mental Disorders of the Elderly Cognitive Scale-Revised that we used to define likely dementia.

RESULTS

Overall, the GPCOG and the MMSE were similarly effective at detecting likely dementia. The GPCOG, however, had a higher sensitivity than the MMSE when using published cutpoints.

CONCLUSION

The GPCOG is an effective screening tool for dementia in primary care. It appears to be a viable alternative to the MMSE, whilst also requiring less time to administer.

Predictors of Mortality in Dementia: The PRIME Study

BACKGROUND

Dementia is a terminal illness. While various baseline characteristics of patients, such as age, sex, and dementia severity, are known to predict mortality, little research has examined how changes in patients' symptoms over time predict survival. There are also limited data on patients seen in memory clinics, as opposed to other health care settings, and whether antipsychotic medications are associated with mortality in dementia once patients' demographic and clinical features are controlled for.

OBJECTIVE

To identify predictors of mortality in patients with dementia.

METHOD

Of 970 patients recruited from nine memory clinics around Australia, 779 patients had dementia at baseline. Patients completed measures of dementia severity, cognition, functional ability, neuropsychiatric symptoms, caregiver burden, and medication use at baseline and at regular intervals over a three-year period. Mortality data were obtained from state registries eight years after baseline.

RESULTS

Overall, 447 (57.4%) of the patients with dementia died within the eight years. Older age, male sex, more severe dementia and functional impairment at baseline, greater decline in dementia severity and functional impairment over six months, taking a larger number of medications, and use of atypical antipsychotic medication predicted earlier mortality.

CONCLUSIONS

The findings confirm that demographic and diagnostic features predict the survival of patients with dementia. Importantly, the findings indicate that changes in dementia severity and functional impairment over time predict mortality independently of baseline levels, and provide further evidence for the higher mortality risk of patients taking antipsychotic medications.

Cognition and mortality in older people: the Sydney Memory and Ageing Study

BACKGROUND

Both cognitive ability and cognitive decline have been shown to predict mortality in older people. As dementia, a major form of cognitive decline, has an established association with shorter survival, it is unclear the extent to which cognitive ability and cognitive decline predict mortality in the absence of dementia.

OBJECTIVE

To determine whether cognitive ability and decline in cognitive ability predict mortality in older individuals without dementia.

DESIGN

The Sydney Memory and Ageing Study is an observational population-based cohort study. Participants completed detailed neuropsychological assessments and medical examinations to assess for risk factors such as depression, obesity, hypertension, diabetes, hypercholesterolaemia, smoking and physical activity. Participants were regularly assessed at 2-year intervals over 8 years.

SETTING

A community sample in Sydney, Australia.

SUBJECTS

One thousand and thirty-seven elderly people without dementia.

RESULTS

Overall, 236 (22.8%) participants died within 8 years. Both cognitive ability at baseline and decline in cognitive ability over 2 years predicted mortality. Decline in cognitive ability, but not baseline cognitive ability, was a significant predictor of mortality when depression and other medical risk factors were controlled for. These relationships also held when excluding incident cases of dementia.

CONCLUSIONS

The findings indicate that decline in cognition is a robust predictor of mortality in older people without dementia at a population level. This relationship is not accounted for by co-morbid depression or other established biomedical risk factors.

A cognitive account of belief: a tentative road map

Over the past decades, delusions have become the subject of growing and productive research spanning clinical and cognitive neurosciences. Despite this, the nature of belief, which underpins the construct of delusions, has received little formal investigation. No account of delusions, however, would be complete without a cognitive level analysis of belief per se. One reason for this neglect is the assumption that, unlike more established and accessible modular psychological process (e.g., vision, audition, face-recognition, language-processing, and motor-control systems), beliefs comprise more distributed and therefore less accessible central cognitive processes. In this paper, we suggest some defining characteristics and functions of beliefs. Working back from cognitive accounts of delusions, we consider potential candidate cognitive processes that may be involved in normal belief formation. Finally, we advance a multistage account of the belief process that could provide the basis for a more comprehensive model of belief.

Social cognition and social judgment in schizophrenia

Schizophrenia typically involves poor social functioning. This may be due, in part, to deficits in theory-of-mind, the cognitive ability to reason flexibly about the mental states of others. Patients also have deficits in social knowledge. It is currently unclear how these two impairments interrelate in schizophrenia. To address this issue, 43 patients with schizophrenia and 25 healthy controls completed two theory-of-mind tests and a novel test of social judgment. This latter measure required participants to judge whether various social behaviors were normal or reasonable in the context in which the behaviors occurred. Whereas patients demonstrated clear deficits in theory-of-mind, they performed similarly to controls when judging socially appropriate behaviors and violations of social norms. Patients, however, were less likely than controls to judge social behavior as reasonable when the behavior was impolite but understandable if the characters’ thoughts were taken into account. This latter difficulty correlated with patients’ performance deficits on the theory-of-mind tasks. Overall, findings suggest that basic social knowledge is intact in schizophrenia, though judgments of social behavior are affected by patients’ theory-of-mind deficits.

Theory of mind and neurocognition in early psychosis: a quasi-experimental study

BACKGROUND

People with chronic psychosis often display theory of mind impairments that are not fully accounted for by other, more general neurocognitive deficits. In these patients, both theory of mind and neurocognitive deficits contribute to poor functioning, independently of psychotic symptoms. In young people with recent-onset psychosis, however, it is unclear the extent to which theory of mind impairment is independent of neurocognitive deficits. The primary aim of this study was to examine the evidence for specific theory of mind impairments in early psychosis. A secondary aim was to explore the relations between theory of mind, neurocognition, symptom severity, and functional outcomes.

METHODS

Twenty-three patients who were within two years of their first psychotic episode and 19 healthy controls completed theory of mind and neurocognitive batteries. Social functioning, quality of life, and symptom severity were also assessed in patients.

RESULTS

Patients demonstrated deficits in tasks assessing theory of mind and neurocognition relative to controls. Patients' deficits in theory of mind were evident even after adjusting for their deficits in neurocognition. Neither theory of mind nor neurocognition predicted social functioning or quality of life in this early psychosis sample. Severity of negative symptoms, however, was a significant predictor of both outcomes.

CONCLUSIONS

While a specific theory of mind impairment was evident in this early psychosis sample, severity of negative symptoms emerged as the best predictor of poor functional outcome. Further early psychosis research is needed to examine the longitudinal progression of theory of mind impairments - independent of neurocognitive deficits - and their impact on psychosocial function.

Progression from mild cognitive impairment to dementia: a 3-year longitudinal study

OBJECTIVE

To examine characteristics that predict the progression from mild cognitive impairment to dementia.

METHODS

Of 970 patients recruited from nine memory clinics around Australia, 185 had mild cognitive impairment diagnosed. Measures of cognitive ability, functional ability, and neuropsychiatric symptoms were completed at baseline and over 3 years of follow up.

RESULTS

Over 3 years, 52 (28%) patients with mild cognitive impairment developed dementia. Older age, lower cognitive ability at baseline, and faster decline in cognitive ability over the first 6 months of follow up, but not depression, predicted progression to dementia.

CONCLUSIONS

The findings confirm that simple clinical data such as age, cognitive ability at baseline, and rate of cognitive decline are important predictors of progression from mild cognitive impairment to dementia over 3 years.

Theory of mind in early psychosis

AIM

A deficit in theory of mind--the ability to infer and reason about the mental states of others - might underpin the poor social functioning of patients with psychosis. Unfortunately, however, there is considerable variation in how such a deficit is assessed. The current study compared three classic tests of theory of mind in terms of their ability to detect impairment in patients in the early stages of psychosis.

METHODS

Twenty-three patients within 2 years of their first psychotic episode and 19 healthy controls received picture-sequencing, joke-appreciation and story-comprehension tests of theory of mind.

RESULTS

Whereas the picture-sequencing and joke-appreciation tests successfully detected a selective theory-of-mind deficit in patients, the story-comprehension test did not.

CONCLUSIONS

The findings suggest that tests that place minimal demands on language processing and involve indirect, rather than explicit, instructions to assess theory of mind might be best suited to detecting theory-of-mind impairment in early stages of psychosis.

Using hypnosis to disrupt face processing: mirrored-self misidentification delusion and different visual media

Mirrored-self misidentification delusion is the belief that one's reflection in the mirror is not oneself. This experiment used hypnotic suggestion to impair normal face processing in healthy participants and recreate key aspects of the delusion in the laboratory. From a pool of 439 participants, 22 high hypnotisable participants ("highs") and 20 low hypnotisable participants were selected on the basis of their extreme scores on two separately administered measures of hypnotisability. These participants received a hypnotic induction and a suggestion for either impaired (i) self-face recognition or (ii) impaired recognition of all faces. Participants were tested on their ability to recognize themselves in a mirror and other visual media - including a photograph, live video, and handheld mirror - and their ability to recognize other people, including the experimenter and famous faces. Both suggestions produced impaired self-face recognition and recreated key aspects of the delusion in highs. However, only the suggestion for impaired other-face recognition disrupted recognition of other faces, albeit in a minority of highs. The findings confirm that hypnotic suggestion can disrupt face processing and recreate features of mirrored-self misidentification. The variability seen in participants' responses also corresponds to the heterogeneity seen in clinical patients. An important direction for future research will be to examine sources of this variability within both clinical patients and the hypnotic model.

Jumping to delusions in early psychosis

INTRODUCTION

Patients with delusions typically seek less information when making decisions than controls ("jumping-to-conclusions", JTC) and paradoxically over-adjust to counter-evidence on probabilistic reasoning tasks. Previous studies have examined JTC bias across the delusion-prone continuum, but have not considered the co-occurrence of both biases at early stages of psychosis. This was our aim.

METHOD

Twenty-three early psychosis patients and 19 healthy controls completed two versions of the probabilistic reasoning task: a "draws-to-decision" version (to assess JTC) and a "graded-estimates" version (to assess over-adjustment). Both versions have been used previously with clinically delusional people with schizophrenia. IQ, memory and executive function were also examined.

RESULTS

Patients took fewer trials to reach a decision in the draws-to-decision version and showed greater over-adjustment to counter-evidence in the graded-estimates version than controls. Across groups, those who jumped to conclusions showed greater over-adjustment. Poor executive function predicted more extreme biases in controls but not in patients. Task performances were unrelated to memory. Similar results were evident in patient and control subgroups matched on IQ, and years of formal education.

CONCLUSIONS

A jumping-to-conclusions bias and an over-adjustment bias co-occurred in the early psychosis patients. Implications are discussed concerning the role of such biases in delusion-proneness.

Masked and unmasked priming in schizophrenia

Dehaene et al. (2003) showed an absence of conscious, but not masked, conflict effects when patients with schizophrenia performed a number-categorisation priming task. We aimed to replicate these influential results using a different word-categorisation priming task. Counter to Dehaene et al.'s findings, 21 patients and 20 healthy controls showed similar congruence effects for both masked and visible primes. Within patients, a reduced congruence effect for visible primes associated with longer duration of illness and more severe behavioural disorganisation. Patients, unlike controls, were no slower to respond to targets that followed visible compared to masked primes. Conscious conflict effects on priming tasks are not universally reduced in schizophrenia but may associate with chronicity and behavioural disorganisation. That patients were no slower when the preceding primes were clearly visible accords with evidence elsewhere that information processing in schizophrenia is driven more by immediate conscious experience and constrained less by prior events.