The usability of daytime and night-time heart rate dynamics as digital biomarkers of depression severity.

BACKGROUND: Alterations in heart rate (HR) may provide new information about physiological signatures of depression severity. This 2-year study in individuals with a history of recurrent major depressive disorder (MDD) explored the intra-individual variations in HR parameters and their relationship with depression severity. METHODS: Data from 510 participants (Number of observations of the HR parameters = 6666) were collected from three centres in the Netherlands, Spain, and the UK, as a part of the remote assessment of disease and relapse-MDD study. We analysed the relationship between depression severity, assessed every 2 weeks with the Patient Health Questionnaire-8, with HR parameters in the week before the assessment, such as HR features during all day, resting periods during the day and at night, and activity periods during the day evaluated with a wrist-worn Fitbit device. Linear mixed models were used with random intercepts for participants and countries. Covariates included in the models were age, sex, BMI, smoking and alcohol consumption, antidepressant use and co-morbidities with other medical health conditions. RESULTS: Decreases in HR variation during resting periods during the day were related with an increased severity of depression both in univariate and multivariate analyses. Mean HR during resting at night was higher in participants with more severe depressive symptoms. CONCLUSIONS: Our findings demonstrate that alterations in resting HR during all day and night are associated with depression severity. These findings may provide an early warning of worsening depression symptoms which could allow clinicians to take responsive treatment measures promptly.

Social functioning and subclinical psychosis in adolescence: a longitudinal general adolescent population study.

OBJECTIVES: To investigate the longitudinal relationship between subclinical psychotic symptoms and social functioning in a representative general population sample of adolescents. METHOD: Data were derived from a routine general health screening of 1909 adolescents in a circumscribed region. Baseline measurement was in the second grade of secondary school (T0), and follow-up occurred approximately 2 years later (T1). Social functioning and subclinical psychotic symptoms of hallucinations and delusions were assessed at both time points. RESULTS: Baseline (T0) social problems preceded follow-up (T1) subclinical delusions, but not T1 subclinical hallucinations. Similarly, T0 delusions preceded social problems at T1, but T0 hallucinations did not. CONCLUSION: This longitudinal general population study demonstrated a bidirectional association between social problems and delusions, but found no link between social problems and hallucinations. This may reflect a downward negative spiral where delusional thoughts and social problems reinforce each other.

Remote assessment of disease and relapse in major depressive disorder (RADAR-MDD): a multi-centre prospective cohort study protocol.

BACKGROUND: There is a growing body of literature highlighting the role that wearable and mobile remote measurement technology (RMT) can play in measuring symptoms of major depressive disorder (MDD). Outcomes assessment typically relies on self-report, which can be biased by dysfunctional perceptions and current symptom severity. Predictors of depressive relapse include disrupted sleep, reduced sociability, physical activity, changes in mood, prosody and cognitive function, which are all amenable to measurement via RMT. This study aims to: 1) determine the usability, feasibility and acceptability of RMT; 2) improve and refine clinical outcome measurement using RMT to identify current clinical state; 3) determine whether RMT can provide information predictive of depressive relapse and other critical outcomes. METHODS: RADAR-MDD is a multi-site prospective cohort study, aiming to recruit 600 participants with a history of depressive disorder across three sites: London, Amsterdam and Barcelona. Participants will be asked to wear a wrist-worn activity tracker and download several apps onto their smartphones. These apps will be used to either collect data passively from existing smartphone sensors, or to deliver questionnaires, cognitive tasks, and speech assessments. The wearable device, smartphone sensors and questionnaires will collect data for up to 2-years about participants' sleep, physical activity, stress, mood, sociability, speech patterns, and cognitive function. The primary outcome of interest is MDD relapse, defined via the Inventory of Depressive Symptomatology- Self-Report questionnaire (IDS-SR) and the World Health Organisation's self-reported Composite International Diagnostic Interview (CIDI-SF). DISCUSSION: This study aims to provide insight into the early predictors of major depressive relapse, measured unobtrusively via RMT. If found to be acceptable to patients and other key stakeholders and able to provide clinically useful information predictive of future deterioration, RMT has potential to change the way in which depression and other long-term conditions are measured and managed.

An Experience Sampling Method Intervention for Dementia Caregivers: Results of a Randomized Controlled Trial.

OBJECTIVE: Ecological momentary interventions integrated with real-life assessments using the experience sampling method (ESM) could be promising to effectively support dementia caregivers in daily life. This study reports on the effectiveness of the ESM-based intervention "Partner in Sight." DESIGN, SETTING, PARTICIPANTS: A randomized controlled trial with 76 dementia caregivers was performed. Participants were randomly assigned to the intervention group ("Partner in Sight": ESM self-monitoring and personalized feedback), the pseudo-intervention group (ESM self-monitoring without feedback), or the control group (usual care). MEASUREMENTS: Effects were evaluated pre- and postintervention and at 2-month follow-up. Primary outcomes were retrospective measures of caregiver sense of competence and mastery. Secondary outcomes were retrospective measures of depression, anxiety, and perceived stress. Complementary ESM measures of positive and negative affect were collected pre- and postintervention. RESULTS: Both the experimental and pseudo-experimental groups showed an increase in retrospective sense of competence and a decrease in perceived stress at 2-month follow-up. At postintervention, the experimental group showed a decrease in momentary negative affect compared with the pseudo-experimental and control groups. No effects were found for retrospective mastery, depression, anxiety, and momentary positive affect. CONCLUSIONS: ESM interventions could be an important asset for increasing caregiver resources and could help caregivers to better adapt and manage difficult situations and to protect against negative emotions.

[Personalised medicine: from a scientific perspective]. / Personalised medicine: wat betekent dit voor wetenschappelijk onderzoek?

BACKGROUND: The goal of personalised medicine is to adapt the therapy precisely to an individual's specific needs. But how can we practise personalised medicine from a scientific perspective?
AIM: To discuss how we can progress from a science based on group findings to a science based on individual cases.
METHOD: We will outline various research designs that may be helpful for investigating an approach to personalised medicine.
RESULTS: One approach is to focus on more homogenous groups, e.g. using symptom dimensions or by dividing the groups on the basis of biomarkers, sociomarkers or psychomarkers. Another approach is to study variations within an individual, adjusting the intervention precisely to the individual, both in terms of content and timing.
CONCLUSION: Designs that allow for a scientific approach to personalised medicine should improve our understanding of what is happening to a specific individual and enable us to select the most suitable intervention for a specific individual.

Does the Social Functioning Scale reflect real-life social functioning? An experience sampling study in patients with a non-affective psychotic disorder and healthy control individuals.

BACKGROUND: The ecological validity of retrospective measures of social functioning is currently unknown in patients with schizophrenia. In the present study, patients with a diagnosis of non-affective psychosis were compared with controls on two measures of social functioning: the Social Functioning Scale (SFS) and daily-life measures collected with the Experience Sampling Methodology (ESM). The associations between both measures were examined in each group of participants to test for the ecological validity of the SFS. METHODS: A total of 126 participants with a non-affective psychotic disorder and 109 controls completed the SFS and a 6-day momentary ESM protocol assessing various aspects of social functioning. Multiple linear and multilevel regression analyses were performed to test for group differences in social functioning level and examine associations between the two assessment techniques. RESULTS: Lower social functioning was observed in patients compared with controls on retrospective and momentary measures. The SFS interpersonal domain (social engagement/withdrawal and interpersonal behaviour dimensions) was associated with the percentage of time spent alone and negative appraisal of social interactions. The SFS activity domain (pro-social and recreational activities dimensions) was negatively associated with time spent in leisure activities. CONCLUSIONS: The SFS showed some degree of ecological validity at assessing broad aspects of social functioning. Low scores on the SFS social engagement/withdrawal and interpersonal behaviour dimensions captured social isolation and social avoidance in daily life, but not lack of interest in socializing. Ecological validity of the SFS activity domain was low. ESM offers a rich alternative to classical assessment techniques of social functioning.

The role of stress-regulation genes in moderating the association of stress and daily-life psychotic experiences.

OBJECTIVE: The interaction of single nucleotide polymorphisms with both distal and proximal environmental factors across the extended psychosis phenotype is understudied. This study examined (i) the interaction of relevant SNPs with both early-life adversity and proximal (momentary) stress on psychotic experiences (PEs) in an extended psychosis sample; and (ii) differences between early-psychosis and non-clinical groups for these interactions. METHODS: Two hundred and forty-two non-clinical and 96 early-psychosis participants were prompted randomly eight times daily for 1 week to complete assessments of current experiences, including PEs and stress. Participants also reported on childhood trauma and were genotyped for 10 SNPs on COMT, RGS4, BDNF, FKBP5, and OXTR genes. RESULTS: Unlike genetic variants, distal and proximal stressors were associated with PEs in both samples and were more strongly associated with PEs in the early-psychosis than in the non-clinical group. The RGS4 TA and FKBP5 CATT haplotypes interacted with distal stress, whereas the A allele of OXTR (rs2254298) interacted with proximal stress, increasing momentary levels of PEs in the early-psychosis group. No interactions emerged with COMT or BDNF variants. CONCLUSION: Individual differences in relevant stress-regulation systems interact with both distal and proximal psychosocial stressors in shaping the daily-life manifestation of PEs across the psychosis continuum.

Clinical high risk for psychosis: the association between momentary stress, affective and psychotic symptoms.

OBJECTIVE: The aim of this study was to assess associations between momentary stress and both affective and psychotic symptoms in everyday life of individuals at clinical high risk (CHR), compared to chronic psychotic patients and healthy controls, in search for evidence of early stress sensitization. It also assessed whether psychotic experiences were experienced as stressful. METHOD: The experience sampling method was used to measure affective and psychotic reactivity to everyday stressful activities, events and social situations in 22 CHR patients, 24 patients with a psychotic disorder and 26 healthy controls. RESULTS: Multilevel models showed significantly larger associations between negative affect (NA) and activity-related stress for CHR patients than for psychotic patients (P = 0.008) and for CHR compared to controls (P < 0.001). Similarly, the association between activity-related stress and psychotic symptoms was larger in CHR than in patients (P = 0.02). Finally, the association between NA and symptoms (P < 0.001) was larger in CHR than in patients. CONCLUSION: Stress sensitization seems to play a role particularly in the early phase of psychosis development as results suggest that CHR patients are more sensitive to daily life stressors than psychotic patients. In this early phase, psychotic experiences also contributed to the experience of stress.

Dealing with daily challenges in dementia (deal-id study): an experience sampling study to assess caregiver functioning in the flow of daily life.

OBJECTIVE: Accurate assessment of caregiver functioning is of great importance to gain better insight into daily caregiver functioning and to prevent high levels of burden. The experience sampling methodology (ESM) is an innovative approach to assess subjective experiences and behavior within daily life. In this study, the feasibility of the ESM in spousal caregivers of people with dementia was examined, and the usability of ESM data for clinical and scientific practice was demonstrated. METHODS: Thirty-one caregivers collected ESM data for six consecutive days using an electronic ESM device that generated ten random alerts per day. After each alert, short reports of the caregiver's current mood state and context were collected. Feasibility was assessed by examining compliance and subjective experiences with the ESM. Usability was described using group and individual ESM data. RESULTS: Participants on average completed 78.8% of the reports. One participant completed less than 33% of the reports and was excluded from data analyses. Participants considered the ESM device to be a user-friendly device in which they could accurately describe their feelings and experiences. The ESM was not experienced as too burdensome. Zooming in on the ESM data, personalized patterns of mood and contextual factors were revealed. CONCLUSIONS: The ESM is a feasible method to assess caregiver functioning. In addition to standard retrospective measurements, it offers new opportunities to gain more insight into the daily lives of people with dementia and their caregivers. It also provides new possibilities to tailor caregiver support interventions to the specific needs of the caregiver. Copyright © 2016 John Wiley & Sons, Ltd.

Psychological processes underlying the association between childhood trauma and psychosis in daily life: an experience sampling study.

BACKGROUND: Evidence has accumulated that implicates childhood trauma in the aetiology of psychosis, but our understanding of the putative psychological processes and mechanisms through which childhood trauma impacts on individuals and contributes to the development of psychosis remains limited. We aimed to investigate whether stress sensitivity and threat anticipation underlie the association between childhood abuse and psychosis. METHOD: We used the Experience Sampling Method to measure stress, threat anticipation, negative affect, and psychotic experiences in 50 first-episode psychosis (FEP) patients, 44 At-Risk Mental State (ARMS) participants, and 52 controls. Childhood abuse was assessed using the Childhood Trauma Questionnaire. RESULTS: Associations of minor socio-environmental stress in daily life with negative affect and psychotic experiences were modified by sexual abuse and group (all p FWE < 0.05). While there was strong evidence that these associations were greater in FEP exposed to high levels of sexual abuse, and some evidence of greater associations in ARMS exposed to high levels of sexual abuse, controls exposed to high levels of sexual abuse were more resilient and reported less intense negative emotional reactions to socio-environmental stress. A similar pattern was evident for threat anticipation. CONCLUSIONS: Elevated sensitivity and lack of resilience to socio-environmental stress and enhanced threat anticipation in daily life may be important psychological processes underlying the association between childhood sexual abuse and psychosis.

Psychotic reactions to daily life stress and dopamine function in people with severe hearing impairment.

BACKGROUND: Minor stresses measured in daily life have repeatedly been associated with increased momentary psychotic experiences, both in individuals with psychotic disorders and in persons who are genetically at an increased risk for these disorders. Severe hearing impairment (SHI) is an environmental risk factor for psychotic disorder, possibly due to the experience of social exclusion. The aim of the current study is to investigate whether people with SHI exhibit higher levels of psychotic reactivity to social stressors in daily life than normal-hearing controls and whether this reactivity is associated with decreased baseline dopamine (DA) D2/3 receptor availability and/or elevated DA release following a dexamphetamine challenge. METHOD: We conducted an experience sampling study in 15 young adults with SHI and 19 matched normal-hearing controls who had previously participated in a single photon emission computed tomography study measuring DA D2/3 receptor availability and DA release in response to dexamphetamine. RESULTS: The association between social stress and momentary psychotic experiences in daily life was stronger among SHI participants than among normal-hearing controls. Interactions between social stress and baseline striatal DA D2/3 receptor availability or DA release were not significant in multilevel models of momentary psychotic experiences including age, sex and tobacco use. CONCLUSIONS: While both elevated striatal DA release and elevated psychotic stress reactivity have been found in the same population defined by an environmental risk factor, SHI, their inter-relationship cannot be established. Further research is warranted to clarify the association between biological and psychological endophenotypes and psychosis risk.

Exploring the underlying structure of mental disorders: cross-diagnostic differences and similarities from a network perspective using both a top-down and a bottom-up approach.

BACKGROUND: It has been suggested that the structure of psychopathology is best described as a complex network of components that interact in dynamic ways. The goal of the present paper was to examine the concept of psychopathology from a network perspective, combining complementary top-down and bottom-up approaches using momentary assessment techniques. METHOD: A pooled Experience Sampling Method (ESM) dataset of three groups (individuals with a diagnosis of depression, psychotic disorder or no diagnosis) was used (pooled N = 599). The top-down approach explored the network structure of mental states across different diagnostic categories. For this purpose, networks of five momentary mental states ('cheerful', 'content', 'down', 'insecure' and 'suspicious') were compared between the three groups. The complementary bottom-up approach used principal component analysis to explore whether empirically derived network structures yield meaningful higher order clusters. RESULTS: Individuals with a clinical diagnosis had more strongly connected moment-to-moment network structures, especially the depressed group. This group also showed more interconnections specifically between positive and negative mental states than the psychotic group. In the bottom-up approach, all possible connections between mental states were clustered into seven main components that together captured the main characteristics of the network dynamics. CONCLUSIONS: Our combination of (i) comparing network structure of mental states across three diagnostically different groups and (ii) searching for trans-diagnostic network components across all pooled individuals showed that these two approaches yield different, complementary perspectives in the field of psychopathology. The network paradigm therefore may be useful to map transdiagnostic processes.

Childhood abuse and neglect in relation to the presence and persistence of psychotic and depressive symptomatology.

BACKGROUND: The association between childhood trauma and psychotic and depressive symptomatology is well established. However, less is known about the specificity and course of these symptoms in relation to childhood trauma. METHOD: In a large sample (n = 2765) of patients with psychosis (n = 1119), their siblings (n = 1057) and controls (n = 589), multivariate (mixed-effects) regression analyses with multiple outcomes were performed to examine the association between childhood trauma and psychotic and depressive symptomatology over a 3-year period. RESULTS: A dose-response relationship was found between childhood trauma and psychosis. Abuse was more strongly associated with positive symptoms than with negative symptoms whereas the strength of the associations between neglect and positive and negative symptoms was comparable. In patients, similar associations between childhood trauma and psychotic or depressive symptoms were found, and in siblings and controls, stronger associations were found between trauma and depressive symptomatology. Childhood trauma was not related to a differential course of symptoms over a 3-year time period. CONCLUSIONS: In congruence with earlier work, our findings suggest that childhood trauma, and abuse in particular, is associated with (subthreshold) psychosis. However, childhood trauma does not seem to be associated with a differential course of symptoms, nor does it uniquely heighten the chance of developing (subthreshold) psychotic symptomatology. Our results indicate that trauma may instead contribute to a shared vulnerability for psychotic and depressive symptoms.

Sexual minority status and psychotic symptoms: findings from the Netherlands Mental Health Survey and Incidence Studies (NEMESIS).

BACKGROUND: Ethnic minority position is associated with increased risk for psychotic outcomes, which may be mediated by experiences of social exclusion, defeat and discrimination. Sexual minorities are subject to similar stressors. The aim of this study is to examine whether sexual minorities are at increased risk for psychotic symptoms and to explore mediating pathways. METHOD: A cross-sectional survey was performed assessing cumulative incidence of psychotic symptoms with the Composite International Diagnostic Interview in two separate random general population samples (NEMESIS-1 and NEMESIS-2). Participants were sexually active and aged 18-64 years (n = 5927, n = 5308). Being lesbian, gay or bisexual (LGB) was defined as having sexual relations with at least one same-sex partner during the past year. Lifetime experience of any psychotic symptom was analysed using logistic regression, adjusted for gender, educational level, urbanicity, foreign-born parents, living without a partner, cannabis use and other drug use. RESULTS: The rate of any psychotic symptom was elevated in the LGB population as compared with the heterosexual population both in NEMESIS-1 [odds ratio (OR) 2.56, 95% confidence interval (CI) 1.71-3.84] and NEMESIS-2 (OR 2.30, 95% CI 1.42-3.71). Childhood trauma, bullying and experience of discrimination partly mediated the association. CONCLUSIONS: The finding that LGB orientation is associated with psychotic symptoms adds to the growing body of literature linking minority status with psychosis and other mental health problems, and suggests that exposure to minority stress represents an important mechanism.

Positive emotions from social company in women with persisting subclinical psychosis: lessons from daily life.

OBJECTIVE: Altered social reward functioning is associated with psychosis irrespective of stage and severity. Examining the role of social reward functioning prospectively in relation to psychotic experiences before these become persistent and potentially disabling can aid in elucidating social mechanisms that induce shifts toward more severe psychotic states, without the confounding effects of clinical disorder. METHOD: In a longitudinal general population sample (N = 566), the experience sampling method (repetitive random sampling of momentary emotions and social context) was used to assess daily life social functioning at baseline. Persistence of subclinical psychotic experiences was based on the Community Assessment of Psychic Experiences assessed three times over 14 months. Analyses examined to what degree i) social context and ii) appreciation thereof differentiated between those who did and did not develop persistent psychotic experiences. RESULTS: Although individuals with persistent psychotic experiences did not differ in overall level of positive effect, the amount of time spent alone or the level of social satisfaction compared to individuals without persistent psychotic experiences, they were more sensitive to the rewarding effects of social company. CONCLUSION: Alterations in social reward experience may form one of the mechanisms that precede the development of the extended psychosis phenotype over time.

Does social defeat mediate the association between childhood trauma and psychosis? Evidence from the NEMESIS-2 Study.

OBJECTIVE: Based on theoretical considerations and animal studies, mediation of 'social defeat' (SD) in the association between childhood trauma (CT) and psychosis was investigated. METHOD: Trained interviewers administered a structured interview assessing CT, psychotic experiences and other psychopathology in 6646 participants in the second Netherlands Mental Health Survey and Incidence Study (NEMESIS-2). RESULTS: Childhood trauma was associated with psychotic experiences making up the extended psychosis phenotype (EPP), as well as with a diagnosis of psychotic disorder (PD). Similarly, CT was associated with a priori selected items indexing SD (discouraged, hopeless, worthless, loss of self-confidence, low self-esteem, better off dead, suicidal thoughts) and with a measure of affective dysregulation (AD), which in turn were also associated with psychosis. While SD and AD individually acted as mediators in the association between CT and EPP, only SD acted as a mediator in the association between CT and PD. Cannabis use did not mediate the association between CT and EPP or PD. CONCLUSION: The present results suggest a developmental model implicating SD as an important mediator in the link between childhood adverse experiences and later development of psychotic experiences. The combined mediation by SD and AD is compatible with an 'affective pathway' to early psychosis.

The relationship between wearable-derived sleep features and relapse in Major Depressive Disorder.

BACKGROUND: Changes in sleep and circadian function are leading candidate markers for the detection of relapse in Major Depressive Disorder (MDD). Consumer-grade wearable devices may enable remote and real-time examination of dynamic changes in sleep. Fitbit data from individuals with recurrent MDD were used to describe the longitudinal effects of sleep duration, quality, and regularity on subsequent depression relapse and severity. METHODS: Data were collected as part of a longitudinal observational mobile Health (mHealth) cohort study in people with recurrent MDD. Participants wore a Fitbit device and completed regular outcome assessments via email for a median follow-up of 541 days. We used multivariable regression models to test the effects of sleep features on depression outcomes. We considered respondents with at least one assessment of relapse (n = 218) or at least one assessment of depression severity (n = 393). RESULTS: Increased intra-individual variability in total sleep time, greater sleep fragmentation, lower sleep efficiency, and more variable sleep midpoints were associated with worse depression outcomes. Adjusted Population Attributable Fractions suggested that an intervention to increase sleep consistency in adults with MDD could reduce the population risk for depression relapse by up to 22 %. LIMITATIONS: Limitations include a potentially underpowered primary outcome due to the smaller number of relapses identified than expected. CONCLUSION: Our study demonstrates a role for consumer-grade activity trackers in estimating relapse risk and depression severity in people with recurrent MDD. Variability in sleep duration and midpoint may be useful targets for stratified interventions.

Increased stress reactivity: a mechanism specifically associated with the positive symptoms of psychotic disorder.

BACKGROUND: An increased reactivity to stress in the context of daily life is suggested to be an independent risk factor underlying the positive symptoms of psychotic disorder. The aim of this study was to investigate whether positive symptoms moderate the association between everyday stressful events and negative affect (NA), known as stress reactivity. This hypothesis was put to the test in patients with a diagnosis of psychotic disorder. Method The Comprehensive Assessment of Symptoms and History (CASH) and the Positive and Negative Syndrome Scale (PANSS) were used to assess positive and negative symptoms. The experience sampling method (ESM), a structured diary technique, was used to measure stress reactivity and psychotic symptoms in daily life. RESULTS: Higher levels of positive symptoms (CASH: B = 0.14, p = 0.005; PANSS: B = 0.05, p = 0.000; ESM: B = 0.03, p = 0.000) and lower levels of negative symptoms (PANSS: B = - 0.05, p = 0.001) significantly moderate the association between unpleasant events and NA. No significant moderating effect was found for CASH negative symptoms. Moreover, the moderating effect of lifetime and current symptoms on the stress-NA association was significantly larger for those patients with predominantly positive symptoms (CASH: B = 0.09, p = 0.000; PANSS: B = 0.08, p = 0.000; ESM: B = 0.13, p = 0.000). CONCLUSIONS: Patients with a 'psychotic syndrome' with high levels of positive symptoms and low levels of negative symptoms show increased reactivity to stress in daily life, indicating that stress reactivity is a possible risk factor underlying this syndrome.

Hippocampal volume as marker of daily life stress sensitivity in psychosis.

BACKGROUND: Reduced hippocampal size and increased stress sensitivity are associated with psychotic disorder and familial risk for psychosis. However, to what degree the hippocampus is implicated in daily life stress reactivity has not yet been examined. The current study investigated (i) whether familial risk (the contrast between controls, patients and siblings of patients) moderated the relationship between hippocampal volume (HV) and emotional daily stress reactivity and (ii) whether familial risk (the contrast between controls and siblings of patients) moderated the relationship between HV and cortisol daily stress reactivity. Method T1-weighted magnetic resonance imaging (MRI) scans were acquired from 20 patients with schizophrenia, 37 healthy siblings with familial risk for schizophrenia and 32 controls. Freesurfer 5.0.0 was used to measure HV. The experience sampling method (ESM), a structured momentary assessment technique, was used to assess emotional stress reactivity, that is the effect of momentary stress on momentary negative affect (NA). In addition, in the control and sibling groups, cortisol stress reactivity was assessed using momentary cortisol levels extracted from saliva. RESULTS: Multilevel linear regression analyses revealed a significant three-way interaction between group, HV and momentary stress in both the model of NA and the model of cortisol. Increased emotional stress reactivity was associated with smaller left HV in patients and larger total HV in controls. In line with the results in patients, siblings with small HV demonstrated increased emotional and cortisol stress reactivity compared to those with large HV. CONCLUSIONS: HV may index risk and possibly disease-related mechanisms underlying daily life stress reactivity in psychotic disorder.

Is psychotic disorder associated with increased levels of craving for cannabis? An Experience Sampling study.

OBJECTIVE: Although cannabis use among individuals with psychotic disorder is considerable, little is known about patterns of use and factors contributing to continuation of use. Therefore, we investigated craving in relation to cannabis use in patients with psychotic disorder and healthy controls. METHOD: The study included 58 patients with non-affective psychotic disorder and 63 healthy controls; all were frequent cannabis users. Craving was assessed with the Obsessive Compulsive Drug Use Scale (OCDUS) for cannabis, as well as in daily life using the Experience Sampling Method (ESM). RESULTS: Patients scored higher on the OCDUS (B = 1.18, P = 0.022), but did not differ from controls in ESM indices of craving (all P > 0.05). In daily life, ESM craving predicted cannabis use and this was stronger in controls (χ(2) = 4.5, P = 0.033; Bcontrols = 0.08, P < 0.001; Bpatients = 0.06, P < 0.001). In both groups ESM craving was predicted by negative affect, paranoia, and hallucinations (Bnegativeaffect = 0.12, P = 0.009; Bparanoia = 0.13, P = 0.013; Bhallucinations = 0.13, P = 0.028), and followed by an increase in negative affect at non-cannabis-using moments (B = 0.03, P = 0.002). CONCLUSION: The temporal dynamics of craving as well as craving intensity in daily life appear to be similar in patients and controls. Further research is needed to elucidate the inconsistencies between cross-sectional and daily-life measures of craving in psychosis.