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Aim We evaluated the acceptability, usability and safety of Kindred, a novel online intervention for carers of young people with borderline personality disorder (BPD) using a pre–post pilot trial design. The secondary aim explored whether Kindred use was associated with clinical improvements for caregivers on measures of burden of caregiving, stress, expressed emotion, family communication, disability, coping and knowledge of BPD and for patients on measures of severity of BPD symptoms and level of functional impairment. Methods The trial site was the Helping Young People Early program for young people with BPD at Orygen in Melbourne, Australia. Informed consent was obtained from 20 adult carers (i.e., relatives or friends) and 10 young people aged 15–25 with BPD. Kindred, which was available for 3 months, incorporated online psychoeducation, carer-to-carer social networking and guidance from expert and peer moderators. Assessments were completed at baseline and 3 months follow-up. Multiple indicators of acceptability, usability and safety were utilized. Results Seventeen carers were enrolled in Kindred and eight young people completed baseline measures. A priori acceptability, usability and safety criteria were met. Carer burden, stress, expressed emotion, family communication, quality of life, functioning, coping and perceived knowledge of BPD improved at follow-up. Sixty-six percent of the young people (4/6) reported that they believed Kindred had improved their carers' understanding of BPD. Conclusion Kindred was shown to be acceptable, usable and safe, with encouraging improvements in both carer and young person outcomes. Kindred warrants evaluation of its efficacy via an randomized controlled trial.

The ability to exert control over emotions, termed emotion regulation (ER), is vital for everyday functioning. ER success may be influenced by processes relating to the anticipation (prior to active regulation) and implementation (during active regulation) of ER strategy use. We investigated whether brain activity patterns recorded using electroencephalography (EEG) during the first second of anticipation and implementation of two ER strategies—distraction and reappraisal—were related to regulation success. Participants viewed negative images that evoked disgust and sadness. Before each image was presented, participants were cued to either passively view the image or decrease their emotional responses. ER success scores were calculated from subsequent selfreported disgust and sadness ratings. Using multivariate support vector regression, ER success scores were predicted from spatiotemporal patterns of event-related potentials during the first second of anticipation and implementation phases of each ER strategy. For both sadness and disgust, reappraisal success could be predicted during anticipation, while distraction success could be predicted during implementation. These findings suggest that early anticipatory cognitive processes are a key determinant of reappraisal success, but may not be similarly important for distraction. This may be because reappraisal is more cognitively demanding than distraction, requiring enhanced preparation of mental resources.

Exposure to sexual objectification is an everyday experience for many women, yet little is known about its emotional consequences. Fredrickson and Roberts' (1997) objectification theory proposed a within-person process, wherein exposure to sexual objectification causes women to adopt a third-person perspective on their bodies, labeled self-objectification, which has harmful downstream consequences for their emotional well-being. However, previous studies have only tested this model at the between-person level, making them unreliable sources of inference about the proposed intraindividual psychological consequences of objectification. Here, we report the results of Bayesian multilevel structural equation models that simultaneously tested Fredrickson and Roberts' (1997) predictions both within and between persons, using data from 3 ecological momentary assessment (EMA) studies of women's (N = 268) experiences of sexual objectification in daily life. Our findings support the predicted within-person indirect effect of exposure to sexual objectification on increases in negative and self-conscious emotions via self-objectification. However, lagged analyses suggest that the within-person indirect emotional consequences of exposure to sexual objectification may be relatively fleeting. Our findings advance research on sexual objectification by providing the first comprehensive test of the within-person process proposed by Fredrickson and Roberts' (1997) objectification theory. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Emotion regulation (ER) repertoire-the range of different ER strategies an individual utilizes across situations-is assumed to enable more adaptive ER and greater well-being. ER repertoire has been operationalized by a quantitative index (sum of ER strategies across situations) or by applying a person-centered approach to global self-reports of dispositional ER. We aimed to assess ER repertoire in daily life by using an experience sampling methodology (ESM) and a person-centered approach that could account for nested data. We used multilevel latent profile analyses of ESM data (N = 179, 9-10 prompts per day over 21 days) to (a) group the occasions into latent profiles of momentary ER strategies, (b) group individuals whose distributions of ER profiles differed across occasions into latent classes, and (c) examine well-being correlates of class membership at the person level. At the occasion level, we identified nine ER profiles that differed in degree of use (e.g., no use of any vs. strong use of all strategies) and in specific combinations of strategies (e.g., situation selection and acceptance vs. suppression and ignoring). At the person level, we identified 5 classes of individuals differing in the degree to which they used various momentary ER profiles versus one predominant profile across situations. Well-being was highest for individuals who used multiple ER profiles of active strategies and lowest for individuals who used ER profiles focused on suppression. Hence, both ER repertoire width and the specific make-up of the ER repertoire were relevant for the relation between ER repertoire and well-being. (PsycINFO Database Record (c) 2019 APA, all rights reserved). ispartof: Emotion vol:20 issue:8 pages:1462-1474 ispartof: location:United States status: published

IntroductionSpecialised early intervention services have demonstrated improved outcomes in first-episode psychosis (FEP); however, clinical gains may not be sustained after patients are transferred to regular care. Moreover, many patients with FEP remain socially isolated with poor functional outcomes. To address this, our multidisciplinary team has developed a moderated online social media therapy (HORYZONS) designed to enhance social functioning and maintain clinical gains from specialist FEP services. HORYZONS merges: (1) peer-to-peer social networking; (2) tailored therapeutic interventions; (3) expert and peer-moderation; and (4) new models of psychological therapy (strengths and mindfulness-based interventions) targeting social functioning. The aim of this trial is to determine whether following 2 years of specialised support and 18-month online social media-based intervention (HORYZONS) is superior to 18 months of regular care.Methods and analysisThis study is a single-blind randomised controlled trial. The treatment conditions include HORYZONS plus treatment as usual (TAU) or TAU alone. We recruited 170 young people with FEP, aged 16–27 years, in clinical remission and nearing discharge from Early Psychosis Prevention and Intervention Centre, Melbourne. The study includes four assessment time points, namely, baseline, 6-month, 12-month and 18-month follow-up. The study is due for completion in July 2018 and included a 40-month recruitment period and an 18-month treatment phase. The primary outcome is social functioning at 18 months. Secondary outcome measures include rate of hospital admissions, cost-effectiveness, vocational status, depression, social support, loneliness, self-esteem, self-efficacy, anxiety, psychological well-being, satisfaction with life, quality of life, positive and negative psychotic symptoms and substance use. Social functioning will be also assessed in real time through our Smartphone Ecological Momentary Assessment tool.Ethics and disseminationMelbourne Health Human Research Ethics Committee (2013.146) provided ethics approval for this study. Findings will be made available through scientific journals and forums and to the public via social media and the Orygen website.Trial registration numberACTRN12614000009617; Pre-results.

Sexual objectification, particularly of young women, is highly prevalent in modern industrialized societies. Although there is plenty of experimental and cross-sectional research on objectification, prospective studies investigating the prevalence and psychological impact of objectifying events in daily life are scarce. We used ecological momentary assessment to track the occurrence of objectifying events over 1 week in the daily lives of young women (N = 81). Participants reported being targeted by a sexually objectifying event - most often the objectifying gaze - approximately once every 2 days and reported witnessing sexual objectification of others approximately 1.35 times per day. Further, multilevel linear regression analyses showed that being targeted by sexual objectification was associated with a substantial increase in state self-objectification. Overall, individual differences had little impact in moderating these effects.

Antipsychotic medication has been the mainstay of treatment for psychotic illnesses for over 60 years. This has been associated with improvements in positive psychotic symptoms and a reduction in relapse rates. However, there has been little improvement in functional outcomes for people with psychosis. At the same time there is increasing evidence that medications contribute to life shortening metabolic and cardiovascular illnesses. There is also uncertainty as to the role played by antipsychotic medication in brain volume changes. Aim The primary aim of the study is, in a population of young people with first-episode psychosis, to compare functional outcomes between an antipsychotic dose reduction strategy with evidence-based intensive recovery treatment (EBIRT) group (DRS+) and an antipsychotic maintenance treatment with EBIRT group (AMTx+) at 24-months follow-up. Methods Our single-blind randomized controlled trial, within a specialist early psychosis treatment setting, will test the whether the DRS+ group leads to better vocational and social recovery than, the AMTx+ group over a 2-year period in 180 remitted first-episode psychosis patients. Additionally, we will examine the effect of DRS+ vs AMTx+ on physical health, brain volume and cognitive functioning. This study will also determine whether the group receiving DRS+ will be no worse off in terms of psychotic relapses over 2 years follow-up. Results This paper presents the protocol, rationale and hypotheses for this study which commenced recruitment in July 2017. Conclusion This study will provide evidence as to whether an antipsychotic dose-reduction recovery treatment leads to improved functioning and safer outcomes in first-episode psychosis patients. In addition, it will be the first-controlled experiment of the effect of exposure to antipsychotic maintenance treatment on brain volume changes in this population.

Naturalistic studies of emotional reactivity in depression have repeatedly found larger decreases in negative affect (NA) among depressed individuals in response to daily positive events. This so-called mood-brightening (MB) effect represents a theoretical and empirical oddity. The current study is a secondary analysis investigating whether the MB effect is moderated by spontaneous use of emotion regulation strategies, which have been implicated in the maintenance and modulation of NA in prior work. Participants (N = 95) representing a large spectrum of depressive symptom severity reported their experiences of NA and the occurrence of positive events in daily life over the course of seven days using the experience sampling method. Our findings replicate and build upon those of prior studies relating to the MB effect in the following ways: (1) we observed the MB effect for specific negative emotions of sadness, anger, anxiety; and (2) we found evidence that the MB effect is moderated by spontaneous use of rumination, distraction, and expressive suppression, which have been shown to enhance or dampen NA. The role of emotion regulation strategies in daily emotional reactivity to pleasant events is discussed. ispartof: Cognition and Emotion vol:33 issue:6 pages:1291-1301 ispartof: location:England status: published

Emotion differentiation, the ability to make fine-grained distinctions between emotional states, has mainly been studied as a trait. In this research, we examine within-person fluctuations in emotion differentiation and hypothesize that stress is a central factor in predicting these fluctuations. We predict that experiencing stress will result in lower levels of emotion differentiation. Using data from a 3-wave longitudinal experience sampling study, we examined the within-person fluctuations in the level of emotion differentiation across days and months and tested if these fluctuations related to changes in stress levels. On the day-level, we found that differentiation of negative emotions varied significantly within individuals, that high stress levels were associated with lower levels of emotion differentiation, and that stress on 1 day negatively predicted the level of differentiation of negative emotions on a next day (but not vice versa). On the wave-level, we found a concurrent, but not a prospective relationship between stress and emotion differentiation. These results are the first to directly demonstrate the role of stress in predicting fluctuations in emotion differentiation and have implications for our theoretical understanding of emotion differentiation, as well as for interventions. (PsycINFO Database Record ispartof: JOURNAL OF PERSONALITY AND SOCIAL PSYCHOLOGY vol:115 issue:2 pages:179-191 ispartof: location:United States status: published

People differ in the extent to which they experience positive (PA) and negative affect (NA) rather independently or as bipolar opposites. Here, we examine the proposition that the nature of the relation between positive and negative affect in a person's emotional experience is indicative of psychological well-being, in particular the experience of depressive symptoms, typically characterized by diminished positive affect (anhedonia) and increased negative affect (depressed mood). In three experience sampling studies, we examine how positive and negative affective states are related within people's emotional experience in daily life and how the degree of bipolarity of this relation is associated with depressive symptom severity. In Study 1 and 2, we show both concurrently and longitudinally that a stronger bipolar PA-NA relationship is associated with, and in fact is predicted by, higher depressive symptom severity, even after controlling for mean levels of positive and negative affect. In Study 3, we replicate these findings in a daily diary design, with the two conceptually related main symptoms of depression, sadness, and anhedonia, as specific manifestations of high NA and low PA, respectively. Across studies, additional analyses indicate these results are robust across different time scales and various PA and NA operationalizations and that affective bipolarity shows particular specificity toward depressive symptomatology, in comparison with anxiety symptoms. Together, these findings demonstrate that depressive symptoms involve stronger bipolarity between positive and negative affect, reflecting reduced emotional complexity and flexibility. (PsycINFO Database Record

According to social baseline theory (Beckes & Coan, 2011), load sharing is a feature of close relationships whereby the burden of emotional distress is distributed across relationship partners. Load sharing varies by physical closeness and relationship quality. We investigated the effect of load sharing on emotional arousal via galvanic skin response, an indicator of sympathetic nervous system arousal, during a social stressor. Social stress was elicited in 66 adolescent girls (Mage = 15 years) using a spontaneous public-speaking task. Mother−daughter dyads reported their relationship quality, and physical closeness was manipulated by having mothers either touch or not touch their daughter’s hand during the performance. We found evidence of load sharing among dyads who held hands, independent of relationship quality. However, without physical contact, load sharing was only evident among dyads with higher relationship quality. Thus, high relationship quality buffers against threat in a similar way to the physical comfort of a loved one.

The ability to regulate emotions is central to well-being, but healthy emotion regulation may not merely be about using the "right" strategies. According to the strategy-situation-fit hypothesis, emotion-regulation strategies are conducive to well-being only when used in appropriate contexts. This study is the first to test the strategy-situation-fit hypothesis using ecological momentary assessment of cognitive reappraisal-a putatively adaptive strategy. We expected people who used reappraisal more in uncontrollable situations and less in controllable situations to have greater well-being than people with the opposite pattern of reappraisal use. Healthy participants ( n = 74) completed measures of well-being in the lab and used a smartphone app to report their use of reappraisal and perceived controllability of their environment 10 times a day for 1 week. Results supported the strategy-situation-fit hypothesis. Participants with relatively high well-being used reappraisal more in situations they perceived as lower in controllability and less in situations they perceived as higher in controllability. In contrast, we found little evidence for an association between greater well-being and greater mean use of reappraisal across situations.

While in general arousal increases with positive or negative valence (a so-called V-shaped relation), there are large differences among individuals in how these two fundamental dimensions of affect are related in people's experience. In two studies, we examined two possible sources of this variation: personality and culture.In Study 1, participants (Belgian university students) recalled a recent event that was characterized by high or low valence or arousal and reported on their feelings and their personality in terms of the Five-Factor Model. In Study 2, participants from Canada, China/Hong Kong, Japan, Korea, and Spain reported on their feelings in a thin slice of time and on their personality.In Study 1, we replicated the V-shape as characterizing the relation between valence and arousal, and identified personality correlates of experiencing particular valence-arousal combinations. In Study 2, we documented how the V-shaped relation varied as a function of Western versus Eastern cultural background and personality.The results showed that the steepness of the V-shaped relation between valence and arousal increases with Extraversion within cultures, and with a West-East distinction between cultures. Implications for the personality-emotion link and research on cultural differences in affect are discussed.

Emotional inertia—the degree to which people's feelings carry over from one moment to the next—is an important property of the temporal dynamics of emotions. Thus far, emotional inertia has only been examined as a stable, trait-like characteristic. However, internal or external events (e.g., stress) may trigger changes in people's emotion dynamics, particularly among individuals with heightened sensitivity to such events. The current study investigated how emotional inertia is influenced by the anticipation of social stress, and how this effect is moderated by individual differences in depression, self-esteem, and fear of negative evaluation. We measured participants' (n = 71) emotional inertia in daily life using experience sampling before and after experimentally manipulating anticipatory social stress. Consistent with previous research, psychological maladjustment was associated with higher emotional inertia during 'normal' daily life. However, when anticipating a socially stressful event, levels of emotional inertia dropped, particularly among participants scoring high on depression and fear of negative evaluation and low on self-esteem. These results demonstrate that emotion dynamics can vary as a function of contextual factors and identify moderators of such variation.

Four studies investigated whether people tend to see ingroup flaws as part of human nature (HN) to a greater degree than outgroup flaws. In Study 1, people preferentially ascribed high HN flaws to their ingroup relative to two outgroups. Study 2 demonstrated that flaws were rated higher on HN when attributed to the ingroup than when attributed to an outgroup, and no such difference occurred for positive traits. Study 3 replicated this humanizing ingroup flaws (HIF) effect and showed that it was (a) independent of desirability and (b) specific to the HN sense of humanness. Study 4 replicated the results of Study 3 and demonstrated that the HIF effect is amplified under ingroup identity threat. Together, these findings show that people humanize ingroup flaws and preferentially ascribe high HN flaws to the ingroup. These ingroup humanizing biases may serve a group-protective function by mitigating ingroup flaws as “only human.”

The autocorrelation or inertia of negative affect reflects how much negative emotions carry over from moment to moment and has been associated with increased depressive symptoms. In this study, we posed three challenges to this association by examining: (1) whether emotional inertia is relevant for depressive symptoms when assessed on a longer timescale than usual; (2) whether inertia is uniquely related to depressive symptoms after controlling for perseverative thoughts; and (3) whether inertia is related to depressive symptoms over and above the within-person association between affect and perseverative thoughts. Participants (N = 101) provided ratings of affect and perseverative thoughts for 100 days; depressive symptoms were reported before and after the study, and again after 2.5 years. Day-to-day emotional inertia was related to depressive symptoms over and above trait and state perseverative thoughts. Moreover, inertia predicted depressive symptoms when adjusting for its association with perseverative thoughts. These findings establish the relevance of emotional inertia in depressive symptoms independent of perseverative thoughts. peerreview_statement: The publishing and review policy for this title is described in its Aims & Scope. aims_and_scope_url: http://www.tandfonline.com/action/journalInformation?show=aimsScope&journalCode=pcem20 ispartof: Cognition & Emotion vol:29 issue:3 pages:527-538 ispartof: location:England status: published

Emotion regulation has primarily been studied either experimentally or by using retrospective trait questionnaires. Very few studies have investigated emotion regulation in the context in which it is usually deployed, namely, the complexity of everyday life. We address this in the current paper by reporting findings of two experience-sampling studies (Ns = 46 and 95) investigating the use of six emotion-regulation strategies (reflection, reappraisal, rumination, distraction, expressive suppression, and social sharing) and their associations with changes in positive affect (PA) and negative affect (NA) in daily life. Regarding the relative use of emotion-regulation strategies, a highly similar ordering was found across both studies with distraction being used more than sharing and reappraisal. While the use of all six strategies was positively correlated both within- and between-persons, different strategies were associated with distinct affective consequences: Suppression and rumination were associated with increases in NA and decreases in PA, whereas reflection was associated with increases in PA across both studies. Additionally, reappraisal, distraction, and social sharing were related to increases in PA in Study 2. Discussion focuses on how the current findings fit with theoretical models of emotion regulation and with previous evidence from experimental and retrospective studies.

Research has shown that cognitive control processes play a central role in emotion regulation. While most research has examined whether individual differences in such processes are related to the use of these strategies, a crucial next step involves examining whether such differences influence their impact on people's feelings, especially in normal daily life. The present study examined whether impairments in cognitive control (measured using an affective interference resolution task) moderate the impact of using rumination and reappraisal on affective experiences in everyday life (assessed using experience sampling methods). Multilevel analyses revealed that difficulties removing previously relevant negative information from working memory were associated with a larger increase in negative affect following rumination, and smaller increase and decrease in positive and negative affect, respectively, following reappraisal. These findings show that impaired interference resolution for negative information aggravates the deleterious effects of rumination and curbs the benefits of reappraisal in daily life. ispartof: Cognition & Emotion vol:27 issue:3 pages:492-501 ispartof: location:England status: published

Like many other mental disorders, depression is characterised by psychological inflexibility. Two instances of such inflexibility are rumination: repetitive cognitions focusing on the causes and consequences of depressive symptoms; and emotional inertia: the tendency for affective states to be resistant to change. In two studies, we tested the predictions that: (1) rumination and emotional inertia are related; and (2) both independently contribute to depressive symptoms. We examined emotional inertia of subjective affective experiences in daily life among a sample of non-clinical undergraduates (Study 1), and of affective behaviours during a family interaction task in a sample of clinically depressed and non-depressed adolescents (Study 2), and related it to self-reported rumination and depression severity. In both studies, rumination (particularly the brooding facet) and emotional inertia (particularly of sad/dysphoric affect) were positively associated, and both independently predicted depression severity. These findings demonstrate the importance of studying both cognitive and affective inflexibility in depression.

Being human implies a particular moral status: having moral value, agency, and responsibility. However, people are not seen as equally human. Across two studies, we examine the consequences that subtle variations in the perceived humanness of actors or groups have for their perceived moral status. Drawing on Haslam's two-dimensional model of humanness and focusing on three ways people may be considered to have moral status - moral patiency (value), agency, or responsibility - we demonstrate that subtly denying humanness to others has implications for whether they are blamed, praised, or considered worthy of moral concern and rehabilitation. Moreover, we show that distinct human characteristics are linked to specific judgments of moral status. This work demonstrates that everyday judgments of moral status are influenced by perceptions of humanness.

Our perception of how others expect us to feel has significant implications for our emotional functioning. Across 4 studies the authors demonstrate that when people think others expect them not to feel negative emotions (i.e., sadness) they experience more negative emotion and reduced well-being. The authors show that perceived social expectancies predict these differences in emotion and well-being both more consistently than-and independently of-personal expectancies and that they do so by promoting negative self-evaluation when experiencing negative emotion. We find evidence for these effects within Australia (Studies 1 and 2) as well as Japan (Study 2), although the effects of social expectancies are especially evident in the former (Studies 1 and 2). We also find experimental evidence for the causal role of social expectancies in negative emotional responses to negative emotional events (Studies 3 and 4). In short, when people perceive that others think they should feel happy, and not sad, this leads them to feel sad more frequently and intensely.

The aim of the study was to investigate trajectories of social functioning in young people with first-episode psychosis (FEP) with and without cannabis misuse using a secondary analysis of data from the Episode-II trial. Forty-two young people with FEP and comorbid cannabis use disorder were compared with 39 young people with FEP but without a cannabis use disorder. Social functioning was assessed every 6 months during a 30-month follow-up. Multilevel linear growth curve modeling was used to compare the social functioning trajectories over time for those with and without cannabis misuse. Cannabis misuse was not associated with social functioning at baseline assessment. Over a 30-month follow-up, FEP patients without cannabis disorder showed significant improvements in their social functioning, whereas patients with cannabis misuse at baseline displayed no such improvement. Patients with and without cannabis misuse differed significantly in their levels of social functioning after 24 months. Similar results were obtained after adjusting for potential confounders (i.e., age, gender, negative symptoms, premorbid functioning, DSM-IV diagnoses, baseline social functioning and other substance use). In the context of a specialized early intervention service, patients with cannabis misuse at baseline did not attain the improvements in social outcomes observed in their counterparts without cannabis misuse. There is a need to develop effective interventions to reduce cannabis misuse to ultimately improve social outcomes in young people with psychosis. ispartof: PLoS One vol:10 issue:4 pages:1-14 ispartof: location:United States status: published

Background First-episode psychosis most often has its onset during late adolescence. In caring for the young person, families endure high levels of stress and depression. Meanwhile, the social networks of families often erode. Our group has previously shown that family cognitive behaviour therapy (CBT) leads to significantly improved perceived stress compared with specialist first-episode treatment as usual; however, there are well-known barriers to the dissemination of effective family interventions. To address this, we have developed a novel online intervention entitled ‘Altitudes’ that fully integrates purpose-built online social networking, expert and peer moderation, and evidence-based psychoeducation within a single application. The primary aim of this trial is to evaluate the effectiveness of Altitudes in reducing stress in carers over a 6-month period. Methods/design We describe here a single-blinded cluster randomised controlled trial (cRCT) with permutated blocks. The clusters comprise individual families. The two treatment conditions include Altitudes plus Specialist Treatment as Usual (STAU) and STAU alone. Altitudes involves participation in our novel online programme whereas STAU comprises specialist family work at the Early Psychosis Prevention and Intervention Centre (EPPIC), Melbourne, Australia. We aim to recruit 160 family members of young, 15–27 year-old, patients registered for treatment for first-episode psychosis (FEP) at EPPIC. The design includes two assessment time points, namely, baseline and 6-month follow-up. The study is due for completion within 2 years including an 18-month recruitment period and a 6-month treatment phase. The primary outcome is carers’ perceived stress at 6 months. Secondary outcome measures include a biomarker of stress, depressive symptoms, worry, substance use, loneliness, social support, satisfaction with life, and a range of measures that tap into coping resources. We seek to gain a dynamic picture of carer stress through our Smartphone Ecological Momentary Assessment (SEMA) tool. Discussion This is the first randomised controlled trial designed to evaluate an online intervention for carers of young people recovering from FEP. It has the potential to produce evidence in support of a highly novel, accessible, and cost-effective intervention to reduce stress in carers who are providing support to young people at a critical phase in their recovery from psychosis. Trial registration Australian New Zealand Clinical Trial Registry, identifier: ACTRN12616000968471. Retrospectively registered on 22 July 2016. Electronic supplementary material The online version of this article (doi:10.1186/s13063-016-1775-5) contains supplementary material, which is available to authorized users.