Associations between disturbed sleep and attenuated psychotic experiences in people at clinical high risk for psychosis

BACKGROUND

Pre-diagnostic stages of psychotic illnesses, including 'clinical high risk' (CHR), are marked by sleep disturbances. These sleep disturbances appear to represent a key aspect in the etiology and maintenance of psychotic disorders. We aimed to examine the relationship between self-reported sleep dysfunction and attenuated psychotic symptoms (APS) on a day-to-day basis.

METHODS

Seventy-six CHR young people completed the Experience Sampling Methodology (ESM) component of the European Union Gene-Environment Interaction Study, collected through PsyMate® devices, prompting sleep and symptom questionnaires 10 times daily for 6 days. Bayesian multilevel mixed linear regression analyses were performed on time-variant ESM data using the brms package in R. We investigated the day-to-day associations between sleep and psychotic experiences bidirectionally on an item level. Sleep items included sleep onset latency, fragmentation, and quality. Psychosis items assessed a range of perceptual, cognitive, and bizarre thought content common in the CHR population.

RESULTS

Two of the seven psychosis variables were unidirectionally predicted by previous night's number of awakenings: every unit increase in number of nightly awakenings predicted a 0.27 and 0.28 unit increase in feeling unreal or paranoid the next day, respectively. No other sleep variables credibly predicted next-day psychotic symptoms or vice-versa.

CONCLUSION

In this study, the relationship between sleep disturbance and APS appears specific to the item in question. However, some APS, including perceptual disturbances, had low levels of endorsement amongst this sample. Nonetheless, these results provide evidence for a unidirectional relationship between sleep and some APS in this population.

Delayed affective recovery to daily-life stressors signals a risk for depression

OBJECTIVE

The aim of this study is to investigate the time to affective recovery from daily-life stressors between healthy controls (HC) and two groups with an increased risk for developing depression: individuals with subclinical symptoms of depression (SSD), and individuals remitted from a depressive episode with residual symptoms of depression (RRS).

METHOD

The experience sampling method (ESM) was used to measure affective recovery to daily-life stressors. Affective recovery was defined as the moment that negative affect (NA) returned to baseline level following the first stressful event of the day. We assessed two different operationalizations of the baseline: NA at the moment before the stressful event (t_-1), and mean-person NA. The effect of stress intensity, and cumulative stress were also assessed.

RESULTS

Survival analyses showed significantly longer recovery times for the at risk groups in comparison to healthy individuals, albeit no significant difference was found between the two at risk groups (i.e. SSD and RRS). There was also an effect of cumulative stress, but not stress intensity on time to recovery in that cumulative stress resulted in significantly longer recovery times for all three groups.

LIMITATIONS

The present study is limited by the ESM sampling design, assessments take place post-stress and therefore do not capture peak stress. Additionally, we are only able to assess patterns at the group level. Finally, there is a significant age difference between groups.

CONCLUSION

Individuals at risk for depression display a delayed recovery to daily-life stressors when compared to healthy controls, which is not explained by differences in stress intensity or cumulative stress. Understanding what is driving this delay may help combat the development of depression.

The DizzyQuest: relation between self-reported hearing loss, tinnitus and objective hearing thresholds in patients with Meniere's disease

Background

Combining a mobile application-based vestibular diary called the DizzyQuest and an iPad-based hearing test enables evaluation of the relationship between experienced neuro-otological symptoms and hearing thresholds in daily life setting. The aim was to investigate the relationship between self-reported hearing symptoms and hearing thresholds in patients with Meniere’s disease (MD), using the DizzyQuest and the iPad-based hearing test simultaneously.

Methods

The DizzyQuest was administered for 3 weeks in 21 patients. Using the experience-sampling-method (ESM), it assessed hearing loss and tinnitus severity for both ears separately. Each day after the DizzyQuest, an iPad-based hearing test was used to measure hearing thresholds. A mixed model regression analysis was performed to investigate relationships between hearing thresholds and self-reported hearing loss and tinnitus severity.

Results

Fifteen patients were included. Overall, pure-tone averages (PTAs) were not correlated with self-reported hearing loss severity and tinnitus. Individual differences in PTA results between both ears did not significantly influence the difference in self-reported hearing loss severity between both ears. Self-reported hearing loss and tinnitus scores were significantly higher in ears that corresponded with audiometric criteria of MD (p < 0.001). Self-reported tinnitus severity significantly increased with self-reported hearing loss severity in affected (p = 0.011) and unaffected ears (p < 0.001).

Conclusion

Combining the DizzyQuest and iPad-based hearing test, facilitated assessment of self-reported hearing loss and tinnitus severity and their relationship with hearing thresholds, in a daily life setting. This study illustrated the importance of investigating neuro-otological symptoms at an individual level, using multiple measurements. ESM strategies like the DizzyQuest should therefore be considered in neuro-otological research.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-021-10909-8.

[Assertive Treatment as a regular function within mental health]

BACKGROUND

The setting for providing assertive treatment (AT) has changed during the last 30 years in The Netherlands from assertive community treatment (ACT) and flexible assertive community treatment (FACT) to municipalities. The provision of AT varies between municipalities.

AIM

Describing the concept of AT, the nature and size of the target group, and the reasons why people with severe mental illness (SMI) do not seek treatment and the place of AT in mental health care.

METHOD

We used literature en available quantitative data.

RESULTS

AT regularly provided by mental health care is required in patients with SMI and social problems who do not seek treatment. When mental health care and social care collaborate on the level of the patient, treatment and handling of social problems can strengthen each other. This collaboration prevents discontinuity of care and breaking a trusting relationship because patients do not need to be transferred from social service to mental health care or vice versa. AT is on the continuum of voluntarily to compulsory care.AT provided by mental health care (usually provided by FACT-teams) is indicated for SMI patients with social problems and who do not seek treatment. The size of the target group is around 5000 - 20.000 patients in The Netherlands. Reasons not to seek help for people with SMI include within person factor, mental health related factors, or factors related to the interaction of SMI patients and mental health. We advocate for AT to become a regular part of mental health care, and for mental health care and social domain professionals to collaborate on case level. Acting this way, mental health treatment and addressing social problems can reinforce each other and discontinuity of care and breaking a trusting relationship can be prevented. AT is on the continuum of voluntary to involuntary treatment. That is why we suggest AT to be a better term than assertive outreach.

CONCLUSION

It is a given fact that not all patients with SMI and social problems seek treatment. By making AT a regular part of mental health services, we prevent discontinuity of care and we fill the gap between voluntarily and compulsory care.

Introducing the DizzyQuest: an app-based diary for vestibular disorders

Background

Most questionnaires currently used for assessing symptomatology of vestibular disorders are retrospective, inducing recall bias and lowering ecological validity. An app-based diary, administered multiple times in daily life, could increase the accuracy and ecological validity of symptom measurement. The objective of this study was to introduce a new experience sampling method (ESM) based vestibular diary app (DizzyQuest), evaluate response rates, and to provide examples of DizzyQuest outcome measures which can be used in future research.

Methods

Sixty-three patients diagnosed with a vestibular disorder were included. The DizzyQuest consisted of four questionnaires. The morning- and evening-questionnaires were administered once each day, the within-day-questionnaire 10 times a day using a semi-random time schedule, and the attack questionnaire could be completed after the occurrence of a vertigo or dizziness attack. Data were collected for 4 weeks. Response rates and loss-to-follow-up were determined. Reported symptoms in the within-day-questionnaire were compared within and between patients and subgroups of patients with different vestibular disorders.

Results

Fifty-one patients completed the study period. Average response rates were significantly higher than the desired response rate of > 50% (p < 0.001). The attack-questionnaire was used 159 times. A variety of neuro-otological symptoms and different disease profiles were demonstrated between patients and subgroups of patients with different vestibular disorders.

Conclusion

The DizzyQuest is able to capture vestibular symptoms within their psychosocial context in daily life, with little recall bias and high ecological validity. The DizzyQuest reached the desired response rates and showed different disease profiles between subgroups of patients with different vestibular disorders. This is the first time ESM was used to assess daily symptoms and quality of life in vestibular disorders, showing that it might be a useful tool in this population.

Electronic supplementary material

The online version of this article (10.1007/s00415-020-10092-2) contains supplementary material, which is available to authorized users.

Polygenic liability for schizophrenia and childhood adversity influences daily-life emotion dysregulation and psychosis proneness

OBJECTIVE

To test whether polygenic risk score for schizophrenia (PRS-S) interacts with childhood adversity and daily-life stressors to influence momentary mental state domains (negative affect, positive affect, and subtle psychosis expression) and stress-sensitivity measures.

METHODS

The data were retrieved from a general population twin cohort including 593 adolescents and young adults. Childhood adversity was assessed using the Childhood Trauma Questionnaire. Daily-life stressors and momentary mental state domains were measured using ecological momentary assessment. PRS-S was trained on the latest Psychiatric Genetics Consortium schizophrenia meta-analysis. The analyses were conducted using multilevel mixed-effects tobit regression models.

RESULTS

Both childhood adversity and daily-life stressors were associated with increased negative affect, decreased positive affect, and increased subtle psychosis expression, while PRS-S was only associated with increased positive affect. No gene-environment correlation was detected. There is novel evidence for interaction effects between PRS-S and childhood adversity to influence momentary mental states [negative affect (b = 0.07, P = 0.013), positive affect (b = -0.05, P = 0.043), and subtle psychosis expression (b = 0.11, P = 0.007)] and stress-sensitivity measures.

CONCLUSION

Exposure to childhood adversities, particularly in individuals with high PRS-S, is pleiotropically associated with emotion dysregulation and psychosis proneness.

[Positive effects of psychoeducation on mental disorders in the Netherlands]

Mental Health First Aid (mhfa) is a psychoeducation program designed to recognize mental health problems in others, to approach and support them and to refer them to appropriate help.<br/> AIM: To discuss the possible contribution that mhfa can make to the early detection, intervention and destigmatization of mental health problems in the Netherlands.<br/> METHOD: Description of the characteristics, effectiveness and knowledge gaps of mhfa in the Dutch context based on literature and practice.<br/> RESULTS: Positive experiences abroad suggest that mhfa can also contribute to early detection, intervention and destigmatization of mental disorders in the Netherlands. Optimization of the program on the local context is important here.<br/> CONCLUSION: Dutch evaluation- and effect studies are needed to determine whether the positive effects from international research also apply in the Netherlands, whether adults and young people receive early and adequate help thanks to mhfa, and how the stigma surrounding mental disorders can be further reduced.

[Mental health in Bonaire - an inspiration for the Dutch New Mental Health Movement]

In 2010 the bes-islands in the Caribbean became a special municipality of the Netherlands. Healthcare was upgraded to match Dutch standards over a short period of time. With a population of 15,518 inhabitants in 2010 (19,408 in 2016), Bonaire received its own fact-team (flexible assertive community treatment). It subsequently became a unique experiment for the Dutch New Mental Health Movement.<br/> AIM: To describe the development of a modern mental health care system in a limited geographic area.<br/> METHOD: Site visitation, interviews and analysis of historical data sources.<br/> RESULTS: The local mental health team takes integral responsibility for all the mh care needs in Bonaire. There is no intricate diagnostic referral system. Consultation access lines are short. The team was able to dramatically reduce the need for hospitalization. Collaboration with the somatic hospital and general practitioners runs smoothly and the facilities offer complementary care. Societal integration is insured due to mental health professionals living interspersed in the neighborhood, the low threshold allowing them to respond to signals efficiently. There is a natural development of the following three domains of care: reduction of symptoms, societal participation and personal remission.<br/> CONCLUSION: Integrated mental health services in a geographically small area, as presented by the Dutch New Mental Health Movement, enables the possibility of recovery oriented care.

[A study of cost-effectiveness of treating serious mental illness: challenges and solutions]

BACKGROUND People with serious mental illness (SMI) often suffer high healthcare costs and enduring loss of quality of life. Increasing our understanding of the cost-effectiveness of people with SMI is important when striving for optimal health at affordable costs. AIM To describe aspects that can be important for cost-effectiveness research targeting people with SMI. METHOD These aspects are demonstrated by considering pro-active care, rehabilitation and involuntary treatment RESULTS The possible involvement of a large number of stakeholders outside of healthcare requires cost-effectiveness research to also map the costs and benefits outside of healthcare, preferably for each stakeholder specifically. Availability of data, the possibility to combine datasets, and ways to deal with dropouts require extra attention. CONCLUSION Cost-effectiveness research targeting people with SMI could be enhanced when solutions are found for the availability of data inside and outside of healthcare and when dropout can be compensated for by other sources of data, such that costs and benefits for each stakeholder can be estimated more reliably.

Effects of momentary self-monitoring on empowerment in a randomized controlled trial in patients with depression

Background

Interventions based on the experience sampling method (ESM) are ideally suited to provide insight into personal, contextualized affective patterns in the flow of daily life. Recently, we showed that an ESM-intervention focusing on positive affect was associated with a decrease in symptoms in patients with depression. The aim of the present study was to examine whether ESM-intervention increased patient empowerment.

Methods

Depressed out-patients (n = 102) receiving psychopharmacological treatment who had participated in a randomized controlled trial with three arms: (i) an experimental group receiving six weeks of ESM self-monitoring combined with weekly feedback sessions, (ii) a pseudo-experimental group participating in six weeks of ESM self-monitoring without feedback, and (iii) a control group (treatment as usual only). Patients were recruited in the Netherlands between January 2010 and February 2012. Self-report empowerment scores were obtained pre- and post-intervention.

Results

There was an effect of group × assessment period, indicating that the experimental (B = 7.26, P = 0.061, d = 0.44, statistically imprecise) and pseudo-experimental group (B = 11.19, P = 0.003, d = 0.76) increased more in reported empowerment compared to the control group. In the pseudo-experimental group, 29% of the participants showed a statistically reliable increase in empowerment score and 0% reliable decrease compared to 17% reliable increase and 21% reliable decrease in the control group. The experimental group showed 19% reliable increase and 4% reliable decrease.

Conclusions

These findings tentatively suggest that self-monitoring to complement standard antidepressant treatment may increase patients’ feelings of empowerment. Further research is necessary to investigate long-term empowering effects of self-monitoring in combination with person-tailored feedback.

Neuroticism explained? From a non-informative vulnerability marker to informative person-context interactions in the realm of daily life

OBJECTIVES

Despite the well-replicated finding that neuroticism is associated with increased susceptibility for psychopathology, it remains unclear what 'vulnerability as indexed by neuroticism' represents in terms of everyday life emotional processes. This study examined the association between neuroticism and six phenotypes of daily life emotional responses: positive affect (PA), negative affect (NA), PA variability, NA variability, stress sensitivity, and reward experience, and investigated the contribution of genetic and environmental factors to these associations.

DESIGN

A prospective cohort study in a population-based sample of 416 adult female twins.

METHOD

A momentary assessment approach (experience sampling method) was used to collect multiple assessments of affect in daily life. Neuroticism was assessed with the Eysenck Personality Scale. Multi-level regression analyses were carried out to examine the association between neuroticism and the phenotypes of daily life emotional responses. Cross-twin, cross-trait analyses, and bivariate structural equation modelling (SEM) were performed in order to investigate the nature of these associations.

RESULTS

A high neuroticism score was associated with lower momentary PA levels and increased NA variability, independent of momentary NA, PA variability, stress sensitivity, and reward experience. Both the cross-twin, cross-trait analyses, and the bivariate SEM showed that unique, non-shared environmental factors drive the association between neuroticism and PA and that the association between neuroticism and increased NA variability is based on shared genetic factors as well as individual-specific environmental factors.

CONCLUSIONS

Neuroticism as measured by Eysenck questionnaire may index an environmental risk for decreased daily life PA levels and a genetic as well as an environmental risk for increased NA variability. Decomposing the broad measure of neuroticism into measurable persons-context interactions increases its 'informative' value in explaining psychopathology.

Meeting risk with resilience: high daily life reward experience preserves mental health

OBJECTIVE

To examine prospectively whether high reward experience (the ability to generate positive affect boosts from pleasurable daily events) protects against affective symptoms and whether environmental or genetic risk factors moderate protective effects.

METHOD

At baseline, 498 female twins participated in an experience sampling study measuring reward experience in daily life. They also completed questionnaires on childhood adversity and recent stressful life events (SLE). Affective symptoms were measured at baseline and at four follow-ups using SCL-90 anxiety and depression subscales. Co-twin affective symptoms were used as indicators of genetic risk.

RESULTS

Baseline reward experience did not predict follow-up affective symptoms, regardless of level of genetic risk. However, high reward experience was associated with reduced future affective symptoms after previous exposure to childhood adversity or recent SLE.

CONCLUSION

High daily life reward experience increases resilience after environmental adversity; modification of reward experience may constitute a novel area of therapeutic intervention.

Experience sampling research in psychopathology: opening the black box of daily life

A growing body of research suggests that momentary assessment technologies that sample experiences in the context of daily life constitute a useful and productive approach in the study of behavioural phenotypes and a powerful addition to mainstream cross-sectional research paradigms. Momentary assessment strategies for psychopathology are described, together with a comprehensive review of research findings illustrating the added value of daily life research for the study of (1) phenomenology, (2) aetiology, (3) psychological models, (4) biological mechanisms, (5) treatment and (6) gene-environment interactions in psychopathology. Overall, this review shows that variability over time and dynamic patterns of reactivity to the environment are essential features of psychopathological experiences that need to be captured for a better understanding of their phenomenology and underlying mechanisms. The Experience Sampling Method (ESM) allows us to capture the film rather than a snapshot of daily life reality of patients, fuelling new research into the gene-environment-experience interplay underlying psychopathology and its treatment.

A systematic review and meta-analysis of the psychosis continuum: evidence for a psychosis proneness-persistence-impairment model of psychotic disorder

A systematic review of all reported incidence and prevalence studies of population rates of subclinical psychotic experiences reveals a median prevalence rate of around 5% and a median incidence rate of around 3%. A meta-analysis of risk factors reveals associations with developmental stage, child and adult social adversity, psychoactive drug use, and also male sex and migrant status. The small difference between prevalence and incidence rates, together with data from follow-up studies, indicates that approximately 75-90% of developmental psychotic experiences are transitory and disappear over time. There is evidence, however, that transitory developmental expression of psychosis (psychosis proneness) may become abnormally persistent (persistence) and subsequently clinically relevant (impairment), depending on the degree of environmental risk the person is additionally exposed to. The psychosis proneness-persistence-impairment model considers genetic background factors impacting on a broadly distributed and transitory population expression of psychosis during development, poor prognosis of which, in terms of persistence and clinical need, is predicted by environmental exposure interacting with genetic risk.

COMT ValMet moderation of cannabis-induced psychosis: a momentary assessment study of 'switching on' hallucinations in the flow of daily life

OBJECTIVE

A functional polymorphism in the catechol-o-methyltransferase gene (COMT Val(158)Met) may moderate the psychosis-inducing effects of cannabis. In order to extend this finding to dynamic effects in the flow of daily life, a momentary assessment study of psychotic symptoms in response to cannabis use was conducted.

METHOD

The experience sampling technique was used to collect data on cannabis use and occurrence of symptoms in daily life in patients with a psychotic disorder (n = 31) and healthy controls (n = 25).

RESULTS

Carriers of the COMT Val(158)Met Val allele, but not subjects with the Met/Met genotype, showed an increase in hallucinations after cannabis exposure, conditional on prior evidence of psychometric psychosis liability.

CONCLUSION

The findings confirm that in people with psychometric evidence of psychosis liability, COMT Val(158)Met genotype moderates the association between cannabis and psychotic phenomena in the flow of daily life.

The association between cognition and functional outcome in first-episode patients with schizophrenia: mystery resolved?

OBJECTIVE

The presence of a prospective association between cognition and functional outcome in first episode patients with schizophrenia is much debated.

METHOD

Associations between Intelligence Quotient (IQ) measures and functional outcome were assessed at the first hospitalization and after 10 years follow-up.

RESULTS

Functional outcome was associated with estimated premorbid IQ and IQ at 10-year follow-up, but not with IQ assessed at first hospitalization.

CONCLUSION

The presence of a prospective as well as a cross-sectional relationship of the global cognitive measure IQ with 10-year functional outcome could be established. However, assessing associations between cognitive measures assessed at first hospitalization and subsequent functional outcome, can give inconclusive results due to non-uniform intellectual deterioration from premorbid level in the period preceding the first hospitalization.

A momentary assessment study of the relationship between affective and adrenocortical stress responses in daily life

The tendency to experience negative emotions in the face of stress may lead to repeated overactivation of the hypothalamic-pituitary-adrenal axis. In a sample of 556 women, this study used the Experience Sampling Method to assess different daily stressors, current mood, and salivary cortisol, 10 times daily for 5 days. Multilevel analyses estimated the contributions of stressors and mood states as predictors of salivary cortisol secretion. Results showed that minor stressors were associated with decreased positive affect and increased negative affect, agitation, and cortisol. Of the mood states, only negative affect was independently associated with cortisol. Negative affect also mediated effects of daily stressors on cortisol. Although further research is needed to clarify: (i) the causal pathways between daily stress, mood, and cortisol and (ii) the importance of daily stress reactivity as a prospective risk factor, these findings confirm that minor daily stressors can influence emotional and biological processes involved in subjective well-being.

Evidence for instrument and family-specific variation of subclinical psychosis dimensions in the general population

It is unknown to what degree dimensions of schizotypy (subclinical psychosis) show independent, family-specific variation in the general population. Psychologists administered the Community Assessment of Psychic Experiences, the Structured Interview for Schizotypy-Revised (SIS-R), and the Brief Psychiatric Rating Scale to 257 subjects pertaining to 82 general population families. All 3 instruments showed family-specific variation for positive and negative subclinical psychosis dimensions with between-families proportions of total variance between 10% and 40%. However, only the SIS-R showed family-specific variation of the negative dimension independent of its correlation with the positive dimension. The positive dimension of subclinical psychosis shows familial-specific variation in samples unselected for psychiatric disorder, suggesting dimensional liability in the population. The SIS-R additionally captures family-specific variation in the negative domain.

Physical health and depressive symptoms in older Europeans. Results from EURODEP

BACKGROUND

Associations between physical health and depression are consistent across cultures among adults up to 65 years of age. In later life, the impact of physical health on depression is much more substantial and may depend on sociocultural factors.

AIMS

To examine cross-national differences in the association between physical health and depressive symptoms in elderly people across western Europe.

METHOD

Fourteen community-based studies on depression in later life in nine western European countries contributed to a total study sample of 22 570 respondents aged 65 years and older. Measures were harmonized for depressive symptoms (EURO-D scale), functional limitations and chronic physical conditions.

RESULTS

In the majority of the participating samples, the association of depressive symptoms with functional disability was stronger than with chronic physical conditions. Associations were slightly more pronounced in the UK and Ireland.

CONCLUSIONS

The association between physical health and depressive symptoms in later life is consistent across western Europe.

Electronic monitoring of salivary cortisol sampling compliance in daily life

Naturalistic research methods have been developed to collect data in the daily environment, providing ecological valid measures. Recent reports suggest, however, that compliance with fixed time sampling protocols may be problematic and can bias results. This study investigated compliance with an intensive, random time sampling protocol for salivary cortisol and effects of non-compliance on cortisol results. Twenty female twin pairs and nineteen of their sisters were instructed to take saliva samples when signaled at ten unpredictable moments on each of five consecutive days. Subjects recorded collection times, unaware that compliance with the sampling protocol was being investigated by means of electronic monitoring devices. Samples taken < or = 15 min after the signal, according to self-report, were defined as adherent to the protocol. Samples taken < or = 10 min after the self-reported collection time, according to the monitor, were defined as accurate. Self-reported adherence to the sampling protocol was 96.4%. Verified compliance was somewhat lower, with 81% of all saliva samples accurately timed. Contrary to previous reports, inclusion of non-compliant samples in the analysis did not distort the cortisol diurnal profile. Intensive, random time sampling appears to have advantages over fixed time sampling for obtaining valid cortisol profiles when researchers do not have devices to monitor compliance. Results indirectly support the validity of momentary self-report data about daily experiences obtained with the same sampling methods.

Early adolescent cannabis exposure and positive and negative dimensions of psychosis

AIMS

To investigate the effect of exposure to cannabis early in adolescence on subclinical positive and negative symptoms of psychosis.

DESIGN

Cross-sectional survey in the context of an ongoing cohort study.

SETTING

Government-supported general population cohort study.

PARTICIPANTS

A total of 3500 representative 19-year olds in Greece.

MEASUREMENTS

Subjects filled in the 40-item Community Assessment of Psychic Experiences, measuring subclinical positive (paranoia, hallucinations, grandiosity, first-rank symptoms) and negative psychosis dimensions and depression. Drug use was also reported on.

FINDINGS

Use of cannabis was associated positively with both positive and negative dimensions of psychosis, independent of each other, and of depression. An association between cannabis and depression disappeared after adjustment for the negative psychosis dimensions. First use of cannabis below age 16 years was associated with a much stronger effect than first use after age 15 years, independent of life-time frequency of use. The association between cannabis and psychosis was not influenced by the distress associated with the experiences, indicating that self-medication may be an unlikely explanation for the entire association between cannabis and psychosis.

CONCLUSIONS

These results add credence to the hypothesis that cannabis contributes to the population level of expression of psychosis. In particular, exposure early in adolescence may increase the risk for the subclinical positive and negative dimensions of psychosis, but not for depression.

Is our concept of schizophrenia influenced by Berkson's bias?

BACKGROUND

If both positive and negative dimensions of schizophrenia independently influence need for care, a higher estimate of the comorbidity between these dimensions is expected in clinical samples than would be the case if non-clinical cases were investigated (i.e. Berkson's bias). The present paper investigates whether positive and negative dimensions independently contribute to mental health care use in a general population sample.

METHOD

A prospective cohort study was conducted, in which 7076 individuals were interviewed with the Composite International Diagnostic Interview Schedule at baseline and 1 and 3 years later. Lifetime positive and negative psychotic experiences (PPE, NPE) were assessed at baseline. Mental health care use (MHC) was assessed at baseline, and prospectively 1 and 3 years later.

RESULTS

The rating of MHC was strongly associated with NPE and PPE, both retrospectively and prospectively and the effects of both variables remained strong and significant in the analyses with both variables included.

CONCLUSIONS

These results, therefore, suggest that the concept of schizophrenia, as a unitary entity with high comorbidity between positive and negative dimensions, is in part the result of Berkson's bias.

Abnormal response to metabolic stress in schizophrenia: marker of vulnerability or acquired sensitization?

BACKGROUND

Previous work suggests that individuals with schizophrenia display an altered homovanillic acid (HVA) response to metabolic stress. The present study replicated and extended this paradigm, including individuals with elevated genetic risk for schizophrenia.

METHOD

Patients with psychosis (n = 50), non-psychotic first-degree relatives of patients with psychosis (n = 51) and controls without psychosis (n = 50) underwent, in randomized order, double-blind administration of placebo and the glucose analogue 2-deoxy-D-glucose (2DG), which induces a mild, transient clinical state of glucoprivation. Plasma HVA and cortisol were assessed twice before the start of the 2DG/placebo infusion (baseline values), as well as four times post infusion. Data were analysed using multi-level random regression techniques.

RESULTS

During the stress condition, significant increases in plasma HVA and cortisol were found. The increase in plasma HVA level during the stress condition was significantly stronger in patients than in controls, whereas this was not the case in relatives v. controls. The increase in plasma cortisol during the stress condition was significantly less in patients than controls, but no significant difference in the increase of plasma cortisol during stress was found in the comparison between relatives and controls.

CONCLUSIONS

Patients with psychosis, but not their non-psychotic first-degree relatives, show an altered neurobiological response to metabolic stress, suggesting that this dysregulation is not a genetically transmitted vulnerability, but an illness-related effect, possibly reflecting acquired sensitization of neuroendocrine systems by repeated environmental stressors or repeated stimulation with agonistic drugs.

Can cognitive deficits explain differential sensitivity to life events in psychosis?

BACKGROUND

Life events (LE) have been found to influence the onset and course of psychotic disorders. It has been suggested that LE have their effect by increasing underlying sensitivity to daily life stress, a reported vulnerability marker for psychosis. As increased stress-sensitivity and cognitive impairments have been shown to be negatively associated with each other in patient populations, it is attractive to hypothesise that the impact of LE on sensitivity to daily stress is modified by the degree of cognitive impairment, higher levels of cognitive impairment giving rise to reduced impact of LE on daily life stress-sensitivity.

METHODS

Patients with psychotic illness (n = 42) were studied with a) a standard battery of neuropsychological tests to assess cognitive functioning, b) the Experience Sampling Method (a structured diary technique assessing current context and mood in daily life) to assess (i) appraised subjective stress related to daily events and activities, and (ii) emotional reactivity conceptualised as changes in both negative affect (NA) and positive affect (PA), and c) the Brown and Harris Life Event and Difficulties Schedule to assess LE over the last year.

RESULTS

Multilevel regression analyses showed that a prior history of LE increased the sensitivity for daily life stress in subjects with the best performance on the cognitive tests.

CONCLUSIONS

Subjects with cognitive impairments, who already were shown to have lower levels of sensitivity to daily life stress (Myin Germeys et al. 2002), may additionally be less reactive to prior exposure to LE. This result fits with the notion of separate affective and cognitive pathways of symptom formation in psychosis, the cognitive pathway being characterised by severe cognitive deficits and the affective pathway by increased levels of stress-sensitivity associated with prior exposure to LE.

Emotional reactivity to daily life stress in psychosis and affective disorder: an experience sampling study

OBJECTIVE

To investigate the emotional reactivity to small disturbances in daily life in patients with non-affective psychosis (NAP), bipolar disorder (BD) and major depression [major depressive disorder (MDD)].

METHOD

Forty-two patients with NAP, 38 with BD, 46 with MDD, and 49 healthy controls were studied with the experience sampling method to assess (i) appraised subjective stress of small disturbances in daily life and (ii) emotional reactivity, reflected in changes in positive affect (PA) and negative affect (NA).

RESULTS

Multilevel regression analyses showed an increase in NA in MDD, a decrease in PA in BD and both an increase in NA and a decrease in PA in NAP in association with the subjectively stressful situations, compared with the control subjects.

CONCLUSION

Individuals with NAP, MDD and BD display differences in emotional stress reactivity. Type of mood disorder may exert a pathoplastic effect on emotional reactivity in individuals with MDD and BD. Individuals with NAP may be most vulnerable to the effects of daily life stress.

Cerebral tissue alterations and daily life stress experience in psychosis

OBJECTIVE

To examine whether the total volumes of cerebrospinal fluid (CSF), cerebral grey matter and white matter were correlated with the experience of environmental stress in daily life situations.

METHOD

Twenty-seven patients with psychosis underwent magnetic resonance imaging scanning and a random time-sampling self-assessment technique (Experience Sampling Method) to determine subjective daily life stress experiences. Total cerebral tissue volumes were derived from an automated segmentation procedure.

RESULTS

CSF volume was positively associated with daily life event-related stress (beta=0.016, P=0.002), while the association with total white matter was negative (beta=-0.013, P=0.005). The effects were independent of each other and of total cerebral volume and other confounders. No large or significant association was found with grey matter volume.

CONCLUSION

Subjective stress experience in daily life is associated with increased CSF and reduced white matter volumes in patients with psychosis, suggesting functional significance of these cerebral measures.

High expressed emotion: marker for a caring family?

"Expressed emotion" (EE) is considered a marker of dysfunctional family interaction in patients with schizophrenia. An alternative hypothesis, however, is that at least some of the different elements of EE really represent attempts on the part of carers to cope with and care for a relative with a psychiatric disorder. EE (criticism and emotional overinvolvement) was measured in relatives (n = 31) of patients with psychotic illness using the Five-Minute Speech Sample (FMSS). Level of EE was examined in relation to (1) patient-reported family involvement in care over the previous 2 years as indicated by medication monitoring, involvement in treatment decisions, and providing a substitute for institutional care; and (2) symptom severity and number of psychotic episodes. Presence of EE in the relative was strongly associated with the degree of family involvement in care (odds ratio [OR] over three levels: 3.2; 95% confidence interval [CI], 1.1 to 9.0). In addition, presence of high EE was associated with number of psychotic episodes in the previous 5 years in the proband (OR over 0, 1, or 2 episodes: 6.2; 95% CI, 1.2 to 31.9). The association with family involvement was confined to emotional overinvolvement (OR = 9.1; 95% CI, 2.0 to 42.2), whereas the association with previous psychotic episodes was confined to criticism (OR = 20.6; 95% CI, 2.8 to 149.3). Emotional overinvolvement may be a state marker for attempts on the part of relatives to be partners in the care for patients with psychotic illness. High level of criticism may be a trait marker in relatives associated with poor prognosis, but could also develop in reaction to a frequently relapsing illness.

MACS-II: does coping enhance subjective control over psychotic symptoms?

OBJECTIVE

Associations between subjective experience of control and the use of self-initiated coping strategies were examined in patients with psychotic symptoms.

METHOD

Twenty-three patients were interviewed to assess (i) the subjective experience of distress with and control over symptoms and (ii) the coping strategies used.

RESULTS

There was a positive association between coping type and control (OR = 1.07, 95% CI: 1.03-1.12). Active coping strategies had the strongest association with experience of control (active problem-solving: OR = 1.41 95% CI: 1.18-1.68; active problem-avoiding: OR = 1.45 95% CI: 1.18-1.68). Symptomatic coping was negatively associated with control (OR = 0.40, 95% CI: 0.30-0.55), but was the most frequently used strategy. Depressive symptoms were associated with the highest number of coping strategies.

CONCLUSION

Coping strategies differ in the degree and direction of associated subjective control, and symptoms differ in the degree with which coping is mobilized. Assessment of coping strategies may be useful as a prelude to psychological therapy.

Maastricht Assessment of Coping Strategies (MACS-I): a brief instrument to assess coping with psychotic symptoms

OBJECTIVE

To examine the reliability of a brief instrument to assess coping with symptoms by patients with psychotic illness.

METHOD

A semi-structured interview (MACS) was developed to assess the amounts of distress, control and coping in relation to psychotic symptoms. Two raters interviewed 23 symptomatic but stable patients with a diagnosis of chronic schizophrenia on two separate occasions. Case managers were also interviewed.

RESULTS

Both the number of coping strategies used for different groups of symptoms, and the amount of coping used in different domains of coping strategies could be assessed reliably between interviewers (intraclass correlation coefficients range: 0.90-0.97) and between interview sessions (ICCs range: 0.75-0.80). Reliability with case managers, however, was low.

CONCLUSION

The MACS may be a reliable and useful instrument to assess coping in relation to subjective experience of distress by and control over psychotic symptoms.

Single or multiple familial cognitive risk factors in schizophrenia?

The fact that relatives of patients with schizophrenia display subtle cognitive abnormalities suggests genetic transmission of an underlying cognitive endophenotype. It was examined to what extent the cognitive abnormalities that discriminate patients and relatives from controls do so independently of each other, and independent of IQ. Neuropsychological measures were assessed in 50 patients with schizophrenia, 50 first-degree relatives of patients with schizophrenia, and 50 healthy controls. The assessment focused on episodic memory, attentional span, simple and complex speed of information, and semantic memory. Factor analysis of the cognitive test results yielded four factors reflecting speed, episodic memory, working memory, and semantic fluency. Performance of the relatives was intermediate to that of the patients and the controls after adjustment for age, sex, educational level, and IQ. For both patients and relatives, speed of information processing, working memory, and episodic memory independently discriminated from control performance, with a similar pattern in the order of the size of the effects. The results suggest the existence of more than one familial cognitive risk factor for schizophrenia. Independent familial cognitive risk factors may represent separate causal influences or separate indicators of risk related to the same genetic mechanism.

Neighbourhood variation in incidence of schizophrenia. Evidence for person-environment interaction

BACKGROUND

Neighbourhood characteristics may influence the risk of psychosis, independently of their individual-level equivalents.

AIMS

To examine these issues in a multi-level model of schizophrenia incidence.

METHOD

Cases of schizophrenia, incident between 1986 and 1997, were identified from the Maastricht Mental Health Case Register. A multi-level analysis was conducted to examine the independent effects of individual-level and neighbourhood-level variables in 35 neighbourhoods.

RESULTS

Independent of individual-level single and divorced marital status, an effect of the proportion of single persons and proportion of divorced persons in a neighbourhood was apparent (per 1% increase respectively: RR = 1.02; 95% CI 1.00-1.03; and RR = 1.12, 95% CI 1.04-1.21). Single marital status interacted with the neighbourhood proportion of single persons, the effect being stronger in neighbourhoods with fewer single-person households.

CONCLUSIONS

The neighbourhood environment modifies the individual risk for schizophrenia. Premorbid vulnerability resulting in single marital status may be more likely to progress to overt disease in an environment with a higher perceived level of social isolation.