Validity of symptom assessment in psychotic disorders: information variance across different sources of history

Parental mental disorders and offspring schizotypy in middle childhood: an intergenerational record linkage study

PURPOSE

To investigate relationships between distinct schizotypy risk profiles in childhood and the full spectrum of parental mental disorders.

METHODS

Participants were 22,137 children drawn from the New South Wales Child Development Study, for whom profiles of risk for schizophrenia-spectrum disorders in middle childhood (age ~ 11 years) were derived in a previous study. A series of multinomial logistic regression analyses examined the likelihood of child membership in one of three schizotypy profiles (true schizotypy, introverted schizotypy, and affective schizotypy) relative to the children showing no risk, according to maternal and paternal diagnoses of seven types of mental disorders.

RESULTS

All types of parental mental disorders were associated with membership in all childhood schizotypy profiles. Children in the true schizotypy group were more than twice as likely as children in the no risk group to have a parent with any type of mental disorder (unadjusted odds ratio [OR] = 2.27, 95% confidence intervals [CI] = 2.01-2.56); those in the affective (OR = 1.54, 95% CI = 1.42-1.67) and introverted schizotypy profiles (OR = 1.39, 95% CI = 1.29-1.51) were also more likely to have been exposed to any parental mental disorder, relative to children showing no risk.

CONCLUSION

Childhood schizotypy risk profiles appear not to be related specifically to familial liability for schizophrenia-spectrum disorders; this is consistent with a model where liability for psychopathology is largely general rather than specific to particular diagnostic categories.

EPA guidance on assessment of negative symptoms in schizophrenia

Background

During the last decades, a renewed interest for negative symptoms (NS) was brought about by the increased awareness that they interfere severely with real-life functioning, particularly when they are primary and persistent.

Methods

In this guidance paper, we provide a systematic review of the evidence and elaborate several recommendations for the conceptualization and assessment of NS in clinical trials and practice.

Results

Expert consensus and systematic reviews have provided guidance for the optimal assessment of primary and persistent negative symptoms; second-generation rating scales, which provide a better assessment of the experiential domains, are available; however, NS are still poorly assessed both in research and clinical settings.

This European Psychiatric Association (EPA) guidance recommends the use of persistent negative symptoms (PNS) construct in the context of clinical trials and highlights the need for further efforts to make the definition of PNS consistent across studies in order to exclude as much as possible secondary negative symptoms. We also encourage clinicians to use second-generation scales, at least to complement first-generation ones.

The EPA guidance further recommends the evidence-based exclusion of several items included in first-generation scales from any NS summary or factor score to improve NS measurement in research and clinical settings. Self-rated instruments are suggested to further complement observer-rated scales in NS assessment.

Several recommendations are provided for the identification of secondary negative symptoms in clinical settings.

Conclusions

The dissemination of this guidance paper may promote the development of national guidelines on negative symptom assessment and ultimately improve the care of people with schizophrenia.

Reliability and validity of methods for measuring the duration of untreated psychosis: a quantitative review and meta-analysis

BACKGROUND

The duration of untreated psychosis (DUP) has been associated with a wide range of clinical outcomes, and is considered to be one of the key parameters in managing clinical high risk and first episode psychosis patients. However, considerable discrepancies exist in the way that DUP is estimated in different studies. There is no standard or consensus on which method is most reliable and valid for assessing DUP.

METHODS

This review aimed to quantitatively assess different DUP measurement instruments and definitions by comparing their inter-rater reliability, and their strength of validity in predicting biological and clinical outcomes.

RESULTS

Nine instruments designed for measuring DUP were found. Their inter-rater reliability were found to be adequate to excellent, although quite varied. This analysis did not show that any instrument was clearly outstanding compared to the others, although the limited available data do not exclude this possibility. DUP was also significantly associated with a range of outcomes, although mostly with small effect sizes. However, non-instrument based, ad hoc clinical interviews remained the most common way of measuring DUP. Definitions of onset of psychosis and onset of treatment were inconsistent among studies.

CONCLUSIONS

This review did not find quantitative evidence to support the use of one instrument over another. DUP remains a promising modifiable risk factor for a range of long-term clinical outcomes. Future research should quantify and improve the reliability and validity of the structured instruments for DUP measurement.

Youth-caregiver agreement on clinical high-risk symptoms of psychosis

Early identification of individuals who will go on to develop schizophrenia is a difficult endeavor. The variety of symptoms experienced by clinical high-risk youth make it difficult to identify who will eventually develop schizophrenia in the future. Efforts are being made, therefore, to more accurately identify at-risk individuals and factors that predict conversion to psychosis. As in most assessments of children and adolescents, however, both youth and parental report of symptomatology and resulting dysfunction are important to assess. The goals of the current study were to assess the extent of cross-informant agreement on the Structured Interview for Prodromal Symptoms (SIPS), a widely-used tool employed to determine clinical high-risk status. A total of 84 youth-caregiver pairs participated. Youth and caregiver raters displayed moderate overall agreement on SIPS-rated symptoms. Both youth and caregiver ratings of youth symptomatology contributed significantly to predicting conversion to psychosis. In addition, youth age and quality of youth-caregiver relationships appear to be related to cross-informant symptom ratings. Despite differences on individual SIPS domains, the majority of dyads agreed on youth clinical high-risk status. Results highlight the potential clinical utility of using caregiver informants to determine youth psychosis risk.

Future in psychopathology research

Psychopathology research has focused either on the analysis of the mental state in the here and now or on the synthesis of mental status abnormalities with biological markers and outcome data. These two schools of psychopathology, the analytic and the synthetic, make contrasting assumptions, take different approaches, and pursue divergent goals. Analytic psychopathology favors the individual person and unique biography, whereas synthetic psychopathology abstracts from the single case and generalizes to the population level. The dimension of time, especially the prediction of future outcomes, is viewed differently by these two schools. Here I outline how Carpenter's proposal of strong inference and theory testing in psychopathology research can be used to test the value of analytic and synthetic psychopathology. The emerging field of personalized psychiatry can clarify the relevance of psychopathology for contemporary research in psychiatry.

Issues in selection of instruments to measure negative symptoms

Guidance for selection of instruments for measurement of negative symptoms is rapidly evolving. As there are continuing advances in the description of negative symptoms, new instruments are under development, and new data on the performance of instruments emerge from clinical trials. The Scale for Assessment of Negative Symptoms (SANS), the Positive and Negative Syndrome Scale (PANSS), the Marder Negative Factor and the Negative Symptom Assessment-16 (NSA-16) are considered to be reliable and valid measures for negative symptom trials but differ with respect to their domain coverage, use of informants, integration of global scores, administration time and comprehensiveness of their structured interviews. In response to the 2005 NIMH-MATRICS consensus statement, work groups are field testing and refining two new measures, the Clinical Assessment Interview for Negative Symptoms (CAINS) and the Brief Negative Symptom Scale (BNSS). Both address the five currently recognized domains of negative symptoms, differentiate appetitive from consummatory aspects of anhedonia and address desire for social relationships. Thus far, both have exhibited promising psychometric properties.

Relapse duration, treatment intensity, and brain tissue loss in schizophrenia: a prospective longitudinal MRI study

OBJECTIVE

Longitudinal structural MRI studies have shown that patients with schizophrenia have progressive brain tissue loss after onset. Recurrent relapses are believed to play a role in this loss, but the relationship between relapse and structural MRI measures has not been rigorously assessed. The authors analyzed longitudinal data to examine this question.

METHODS

The authors studied data from 202 patients drawn from the Iowa Longitudinal Study of first-episode schizophrenia for whom adequate structural MRI data were available (N=659 scans) from scans obtained at regular intervals over an average of 7 years. Because clinical follow-up data were obtained at 6-month intervals, the authors were able to compute measures of relapse number and duration and relate them to structural MRI measures. Because higher treatment intensity has been associated with smaller brain tissue volumes, the authors also examined this countereffect in terms of dose-years.

RESULTS

Relapse duration was related to significant decreases in both general (e.g., total cerebral volume) and regional (e.g., frontal) brain measures. Number of relapses was unrelated to brain measures. Significant effects were also observed for treatment intensity.

CONCLUSIONS

Extended periods of relapse may have a negative effect on brain integrity in schizophrenia, suggesting the importance of implementing proactive measures that may prevent relapse and improve treatment adherence. By examining the relative balance of effects, that is, relapse duration versus antipsychotic treatment intensity, this study sheds light on a troublesome dilemma that clinicians face. Relapse prevention is important, but it should be sustained using the lowest possible medication dosages that will control symptoms.

MAPK14 and CNR1 gene variant interactions: effects on brain volume deficits in schizophrenia patients with marijuana misuse

BACKGROUND

Adolescent marijuana use is associated with increased risk for schizophrenia. We previously reported that marijuana misuse in conjunction with specific cannabinoid receptor 1 (CNR1) genetic variants (rs12720071-G-allele carriers) contributed to white-matter (WM) brain volume deficits in schizophrenia patients. In this study, we assessed the influence of another cannabinoid-related gene, mitogen-activated protein kinase 14 (MAPK14), and potential MAPK14-CNR1 gene-gene interactions in conferring brain volume abnormalities among schizophrenia patients with marijuana abuse/dependence. MAPK14 encodes a member of the MAPK family involved in diverse cellular processes, including CNR1-induced apoptosis.

METHOD

We genotyped 235 schizophrenia patients on nine MAPK14 tag single nucleotide polymorphisms (tSNPs). Approximately one quarter of the sample had marijuana abuse or dependence. Differential effects of MAPK14 tSNPs on brain volumes across patients with versus without marijuana abuse/dependence were examined using ANCOVA.

RESULTS

Of the MAPK14 tSNPs, only rs12199654 had significant genotype effects and genotype × marijuana misuse interaction effects on WM volumes. rs12199654-A homozygotes with marijuana abuse/dependence had significantly smaller total cerebral and lobar WM volumes. The effects of MAPK14 rs12199654 on WM volume deficits remained significant even after controlling for the CNR1 rs12720071 genotype. There were significant main effects of the MAPK14 CNR1 diplotype and diplotype × marijuana interaction on WM brain volumes, with both genetic variants having additive contributions to WM volume deficits only in patients with marijuana misuse.

CONCLUSIONS

Given that CNR1-induced apoptosis is preceded by increased MAPK phosphorylation, our study suggests that potential MAPK14-CNR1 gene-gene interactions may mediate brain morphometric features in schizophrenia patients with heavy marijuana use.

Validation of the Italian version of Mini-ICF-APP, a short instrument for rating activity and participation restrictions in psychiatric disorders

Aims. The assessment of limitations in social capacities can be done with the Mini-ICF-APP, a rating scale built in reference to the International Classification of Functioning, Disability and Health (ICF). The aim of this study was to assess the reliability and the convergent validity of the Italian version of this scale. Methods. We recruited 120 consecutive patients diagnosed with schizophrenia, major depression, bipolar I disorder and anxiety disorders. Included measures were the Brief Psychiatric Rating Scale (BPRS), the Clinical Global Impression Scale (CGI-S), the Personal and Social Performance Scale (PSP) and the Social and Occupational Functioning Assessment Scale (SOFAS). Results. The median CGI-S and BPRS scores were 5 and 16.5. Mean Mini-ICF-APP total score was 18.1. Schizophrenics' Mini-ICF-APP score was higher, while that of anxious patients was lower than in the other diagnoses. Intra-class correlations (ICC) revealed a significant inter-rater agreement for total score (ICC 0.987) and for each item of the Mini-ICF-APP. The test-retest agreement was also highly significant (ICC 0.993). The total score of the Mini-ICF-APP obtained good negative correlations with PSP (r s = -0.767) and with SOFAS scores (r s = -0.790). The distribution items of the Mini-ICF-APP showed some skewness, indicating that self-care (item 12) and mobility (item 13) were amply preserved in most patients. The Mini-ICF-APP total score was significantly correlated with both CGI-S (r s = 0.777) and BPRS (r s = 0.729). Conclusions. As a short instrument, the Mini-ICF-APP scale seems to be well suited to everyday psychiatric practice as a means of monitoring changes in psychosocial functioning, in particular in schizophrenic patients.

Low intensity cognitive behavioural therapy for psychosis: a pilot study

BACKGROUND AND OBJECTIVES

The dissemination and delivery of psychological therapies for people with psychosis has been limited by workforce and organisational factors. 'Low Intensity' (LI) delivery, whereby staff are trained to deliver brief, focused, manualised interventions, may be one way of improving access. In this study, we piloted a new LI intervention specifically for people with psychosis, aimed at helping people to reach a personal recovery goal, whilst targeting anxious avoidance or depression-related inactivity. Frontline mental health workers were trained to deliver the intervention. We report here on the impact of the intervention on therapeutic outcomes.

METHODS

Twelve people with psychosis and either anxious avoidance or low mood, who wanted to work towards a personal goal, completed the intervention and a battery of assessments of mood, functioning and psychotic symptoms.

RESULTS

Eleven out of the twelve participants achieved their personal goals. The results of a series of Friedman K related sample tests revealed significant improvements in depression, clinical distress, activity levels, negative symptoms and delusions across the three time points, and no change in hallucinations, or anxious avoidance. Staff and participant satisfaction was high.

LIMITATIONS

The study is a small uncontrolled pilot study. Outcomes should therefore be interpreted with caution, pending replication.

CONCLUSIONS

The new LI intervention shows preliminary evidence of effectiveness and is a feasible model of therapy delivery for people with psychosis. The results suggest that frontline mental health workers can be trained relatively easily to deliver the intervention. A larger, randomised controlled trial is warranted to determine the effectiveness of the intervention and training programme.

Concordance between chart review and structured interview assessments of schizophrenic symptoms

BACKGROUND

It is unclear whether direct structured interviews are able to capture the full range of psychopathology in schizophrenia, as is required in diagnostic assessments or clinical ratings. We examined agreement between symptom ratings derived from direct patient interviews and from review of casenotes.

METHODS

The study sample comprised 1021 schizophrenic subjects collected as part of the Irish Case-Control Study of Schizophrenia. Diagnostic interviews used a modified version of the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition. Symptoms were rated by the interviewer. In addition, the Casenote Rating Scale was used to rate symptoms based on medical record information. For each negative and positive symptom, we calculated the Pearson correlation between the interview and the casenote rating. Using the mean of the interview and casenote rating for each symptom, exploratory factor analysis using Varimax rotation was performed.

RESULTS

Three factors were extracted in factor analysis: positive, negative, and Schneiderian symptoms. The highest correlations between interview and casenote ratings were for negative symptoms, in which all symptoms were significantly correlated. Positive and Schneiderian symptoms were significantly correlated with the exception of thought insertion, thought withdrawal, voices speaking in sentences, and somatic hallucinations. Significant correlations were generally moderate (0.2-0.55).

CONCLUSION

Most schizophrenic symptoms, especially negative symptoms, can be assessed by direct interviews as the sole source of information with moderate reliability. However, the presence of some Schneiderian and possibly less prevalent positive symptoms may be difficult to determine without a review of records, which may include longitudinal observations and information from multiple observers.

Caregiver burden in chronic mental illness: the role of patient and caregiver characteristics

The aim of the present study is to identify the relative contribution of patient and caregiver characteristics in a sample of primary carers of patients with chronic mental disorders living in the community. As carers were recruited from caregiver organizations, mainly mothers of an adult child suffering from schizophrenia participated in the study (n = 102). Within a comprehensive transactional stress model, burden was assessed with respect to objective and subjective burden, cognitive-emotional well-being, psychological distress and subjective quality of life. Primary stressors include illness-related characteristics of the patient, and a number of personal dispositions and resources of the caregivers were included as potential moderating variables. Multiple regression analyses were separately calculated for each dimension of burden. Interaction of carers' expressed emotion and external locus of control with the patient's problem with family communication as well as perceived social support was most predictive for objective and subjective burden, whereas carers' neuroticism appeared as the most relevant predictor of their well-being, psychological distress and subjective quality of life. Among the patients' variables, regular employment contributed significantly to reduce carers' distress and enhance their well-being. As the sample was recruited from caregiver organizations, a selection bias has to be taken into account. To reduce caregiver burden, especially mothers' burden, the patients' occupational abilities should be strongly enhanced at an early stage. Family interventions should improve dysfunctional interactions, enhance the carers' social activities and focus more intensely on the carers' own dispositions.

Effects of cannabis use on human brain structure in psychosis: a systematic review combining in vivo structural neuroimaging and post mortem studies

It is unclear yet whether cannabis use is a moderating or causal factor contributing to grey matter alterations in schizophrenia and the development of psychotic symptoms. We therefore systematically reviewed structural brain imaging and post mortem studies addressing the effects of cannabis use on brain structure in psychosis. Studies with schizophrenia (SCZ) and first episode psychosis (FEP) patients as well as individuals at genetic (GHR) or clinical high risk for psychosis (ARMS) were included. We identified 15 structural magnetic resonance imaging (MRI) (12 cross sectional / 3 longitudinal) and 4 post mortem studies. The total number of subjects encompassed 601 schizophrenia or first episode psychosis patients, 255 individuals at clinical or genetic high risk for psychosis and 397 healthy controls. We found evidence for consistent brain structural abnormalities in cannabinoid 1 (CB1) receptor enhanced brain areas as the cingulate and prefrontal cortices and the cerebellum. As these effects have not consistently been reported in studies examining nonpsychotic and healthy samples, psychosis patients and subjects at risk for psychosis might be particularly vulnerable to brain volume loss due to cannabis exposure.

Cannabinoid receptor 1 gene polymorphisms and marijuana misuse interactions on white matter and cognitive deficits in schizophrenia

Marijuana exposure during the critical period of adolescent brain maturation may disrupt neuro-modulatory influences of endocannabinoids and increase schizophrenia susceptibility. Cannabinoid receptor 1 (CB1/CNR1) is the principal brain receptor mediating marijuana effects. No study to-date has systematically investigated the impact of CNR1 on quantitative phenotypic features in schizophrenia and inter-relationships with marijuana misuse. We genotyped 235 schizophrenia patients using 12 tag single nucleotide polymorphisms (tSNPs) that account for most of CB1 coding region genetic variability. Patients underwent a high-resolution anatomic brain magnetic resonance scan and cognitive assessment. Almost a quarter of the sample met DSM marijuana abuse (14%) or dependence (8%) criteria. Effects of CNR1 tSNPs and marijuana abuse/dependence on brain volumes and neurocognition were assessed using ANCOVA, including co-morbid alcohol/non-marijuana illicit drug misuse as covariates. Significant main effects of CNR1 tSNPs (rs7766029, rs12720071, and rs9450898) were found in white matter (WM) volumes. Patients with marijuana abuse/dependence had smaller fronto-temporal WM volumes than patients without heavy marijuana use. More interestingly, there were significant rs12720071 genotype-by-marijuana use interaction effects on WM volumes and neurocognitive impairment; suggestive of gene-environment interactions for conferring phenotypic abnormalities in schizophrenia. In this comprehensive evaluation of genetic variants distributed across the CB1 locus, CNR1 genetic polymorphisms were associated with WM brain volume variation among schizophrenia patients. Our findings suggest that heavy cannabis use in the context of specific CNR1 genotypes may contribute to greater WM volume deficits and cognitive impairment, which could in turn increase schizophrenia risk.

Multiple informants in assessing stress and symptoms in adolescents with schizophrenia

We used exploratory data analysis to examine parents--adolescents congruencies and discrepancies and their correlates in assessing stress and symptoms in adolescents with schizophrenia. A total of 40 adolescents diagnosed with schizophrenia and their parents were drawn from a study of self-management therapy for youth with schizophrenia. Low to moderate congruencies in stress and symptoms were reported (r = .22~.41). Factors including adolescents' age, time spent with children, the number of hospitalizations, and level of disability explained the discrepancies. The results imply that health care providers should be aware that several factors are associated with the discrepancies between parents' and adolescents' reports.

Long-term antipsychotic treatment and brain volumes: a longitudinal study of first-episode schizophrenia

CONTEXT

Progressive brain volume changes in schizophrenia are thought to be due principally to the disease. However, recent animal studies indicate that antipsychotics, the mainstay of treatment for schizophrenia patients, may also contribute to brain tissue volume decrement. Because antipsychotics are prescribed for long periods for schizophrenia patients and have increasingly widespread use in other psychiatric disorders, it is imperative to determine their long-term effects on the human brain.

OBJECTIVE

To evaluate relative contributions of 4 potential predictors (illness duration, antipsychotic treatment, illness severity, and substance abuse) of brain volume change.

DESIGN

Predictors of brain volume changes were assessed prospectively based on multiple informants.

SETTING

Data from the Iowa Longitudinal Study.

PATIENTS

Two hundred eleven patients with schizophrenia who underwent repeated neuroimaging beginning soon after illness onset, yielding a total of 674 high-resolution magnetic resonance scans. On average, each patient had 3 scans (≥2 and as many as 5) over 7.2 years (up to 14 years).

MAIN OUTCOME MEASURE

Brain volumes.

RESULTS

During longitudinal follow-up, antipsychotic treatment reflected national prescribing practices in 1991 through 2009. Longer follow-up correlated with smaller brain tissue volumes and larger cerebrospinal fluid volumes. Greater intensity of antipsychotic treatment was associated with indicators of generalized and specific brain tissue reduction after controlling for effects of the other 3 predictors. More antipsychotic treatment was associated with smaller gray matter volumes. Progressive decrement in white matter volume was most evident among patients who received more antipsychotic treatment. Illness severity had relatively modest correlations with tissue volume reduction, and alcohol/illicit drug misuse had no significant associations when effects of the other variables were adjusted.

CONCLUSIONS

Viewed together with data from animal studies, our study suggests that antipsychotics have a subtle but measurable influence on brain tissue loss over time, suggesting the importance of careful risk-benefit review of dosage and duration of treatment as well as their off-label use.

Computerized measurement of negative symptoms in schizophrenia

Accurate measurement of negative symptoms is crucial for understanding and treating schizophrenia. However, current measurement strategies are reliant on subjective symptom rating scales, which often have psychometric and practical limitations. Computerized analysis of patients' speech offers a sophisticated and objective means of evaluating negative symptoms. The present study examined the feasibility and validity of using widely-available acoustic and lexical-analytic software to measure flat affect, alogia and anhedonia (via positive emotion). These measures were examined in their relationships to clinically-rated negative symptoms and social functioning. Natural speech samples were collected and analyzed for 14 patients with clinically-rated flat affect, 46 patients without flat affect and 19 healthy controls. The computer-based inflection and speech rate measures significantly discriminated patients with flat affect from controls, and the computer-based measure of alogia and negative emotion significantly discriminated the flat and nonflat patients. Both the computer and clinical measures of positive emotion/anhedonia corresponded to functioning impairments. The computerized method of assessing negative symptoms offered a number of advantages over the symptom scale-based approach.

The structure of negative symptoms within schizophrenia: implications for assessment

This review examines the structural validity of negative symptoms focusing on 2 questions: (1) Do negative symptoms represent a domain separate from other symptoms in schizophrenia? and (2) Within negative symptoms, is there a structure that suggests multidimensionality? Results from exploratory and confirmatory factor analytic studies are examined to address these questions. Across studies and symptom instruments, negative symptoms appear to consistently emerge as a factor separate from other dimensions of the illness in schizophrenia. Whether 2-, 3-, or 5-factor models are identified, negative symptoms consistently load on a factor separate from positive symptoms, affective symptoms of depression or anxiety, and symptoms of disorganization. Focusing on negative symptoms themselves, factor analytic findings suggest that this construct is multidimensional with at least 2 factors (involving diminished expression and anhedonia-asociality). Although these factors were replicable, serious limitations were noted in this literature. Thus, 2- (or even 3- or 5-) factor models of negative symptoms should not be considered definitive, but rather all converge to support the general conclusion of the multidimensionality of negative symptoms. The later findings indicate the importance of employing assessments that provide adequate coverage of the broad domain of negative symptoms. Importantly, caution is noted in the interpretability of findings based on existing instruments, and implications for future assessment are discussed.

Multivariate prediction of relatives' stress outcome one year after first hospitalization of schizophrenic and depressed patients

OBJECTIVE

The present study presents the 1-year follow-up findings of the Munich 5-year follow-up study on relatives of first hospitalized patients with schizophrenia or depression. The aim of the study was to determine which factors moderate the impact of the patient's illness on the stress experienced by his key relative in different dimensions.

METHOD

Of the relatives who had participated in the baseline assessment, 90% could be reassessed (n = 69) with respect to their objective and subjective burden, well-being, self-rated symptoms and subjective quality of life as well as different personal dispositions and resources.

RESULTS

Data demonstrate a considerable level of burden in most of the relatives at 1-year follow-up. Compared to baseline, a significant reduction in objective and subjective burden as well as significant improvements in well-being, self-rated symptoms and subjective quality of life occurred in two-thirds of the relatives, while well-being and self-rated symptoms remained worse when compared to norm values. Although stress reduction was significantly associated with patients' residual symptoms on the bivariate level, no main effects on relatives' stress outcome at 1-year follow-up could be observed under multivariate conditions. In multivariate linear regression models for each stress indicator, different combinations of predictors resulted, explaining up to 75% of the total variance of the stress indicators. The most relevant predictors were relatives'expressed emotion and neuroticism, their generalized negative stress response and life stressors, having significant direct and indirect effects on relatives' stress outcome. Stress reduction was mainly caused by an interaction of relatives' generalized positive stress response and patients' residual symptoms.

CONCLUSION

Findings support the transactional character of the stress process in caring for a patient with a severe mental disease. A multidimensional approach is necessary to identify the most important predictors of burden in order to improve family intervention strategies which aim to reduce burden.