While initial anhedonia predicts poor psychotherapy outcomes, little is known about its trajectory during treatment. This study aimed to: (1) identify distinct anhedonia trajectories during high-intensity depression treatment; (2) examine patient and treatment predictors; and (3) compare outcomes across treatment types.

Sessional anhedonia scores (PHQ-9 item-1) from 22,605 patients in NHS talking therapies (primarily receiving either cognitive-behavioral therapy [CBT] or counseling for depression [CfD]) were analyzed using latent growth curve (LGC) and growth mixture modeling. Multinomial logistic regression examined predictors of class membership.

A quadratic LGC model best fit the data, reflecting a decrease in symptoms before leveling out. Six latent classes emerged. Notably, three “non-responder” classes characterized by linear-stable or minimal-change patterns comprised over 50% of the sample (51.3%). In contrast, two “responder” classes (41.4%) exhibited improvement, typically shifting between sessions 4 and 6. This suggests an early “inflection point” where the trajectory of recovery is established. Poorer response was predicted by unemployment, chronic health conditions, psychotropic medication, and longer wait times. There was only a sufficient sample size to compare CBT and CfD treatment types. While CBT was associated with membership in specific classes, the probability of being a “responder” did not differ significantly between CBT and CfD.

Most patients followed non-responder trajectories, highlighting a major efficacy gap for anhedonia in standard depression protocols. The 4–6 session window suggests that if improvement is not observed early, the treatment strategy may require further evaluation. Further research into targeted anhedonia interventions is essential.

In England, psychological therapies provided in primary care are recommended as first-line treatment for people living with mild-to-moderate dementia experiencing depression or anxiety. It is known that people living with dementia experience more barriers to accessing therapy than people without dementia, but such inequalities in terms of rates of access to primary care services are yet to be characterised.

In this retrospective, observational study of linked electronic healthcare records, the national database of the National Health Service (NHS) Talking Therapies for anxiety and depression programme was used to compare pathways to accessing therapy between 6623 people living with dementia and 4 825 489 without dementia between 2012 and 2019. Outcomes included access to an assessment, to therapy and reasons for discharge. Primary analyses used a propensity-score matched cohort to compare outcomes. Exact matching was used for the NHS service entity.

The prevalence of dementia in the study cohort was lower than the prevalence of dementia in a representative population, based on an estimation of prevalence in people with mild-to-moderate age over 35 (0.23% in our study vs 3.82% in previous research). Compared to people without dementia, people living with dementia were less likely to access an assessment (odds ratio [OR] = 0.60; 95% confidence interval [CI]: 0.55–0.65), to subsequently receive therapy (OR = 0.67; 95% CI: 0.61–0.73) and more likely to be discharged because services were deemed not suitable before having an assessment (relative rate ratio [RRR] = 4.90; 95% CI: 4.20–5.72) and starting therapy (RRR = 2.74; 95% CI: 2.24–3.35). Female gender, social deprivation, Asian ethnicity and less common dementia subtypes (such as frontotemporal dementia) were also associated with poorer access rates and a higher likelihood of services being deemed not suitable. Involvement of care partners in the referral process was associated with better access rates.

Pathways to accessing primary care psychological therapy services must be made more accessible for people living with dementia. Better access could be achieved by increasing referrer awareness and training for staff within services to promote access for people living with dementia (especially for groups under-represented in services), better understanding how to involve care partners in the process, as well as when specialist support might be more suited in secondary care. More granularity in the medical coding of rarer dementia diagnoses in electronic health records would also allow for better statistically powered research for these groups.

Peer-supported Open Dialogue (POD) integrates peer practitioners within mental health teams, fostering a collaborative, person-centred and social network approach to care. Although peer practitioners are increasingly involved in Open Dialogue, the role of peer practitioners within such teams remains underexplored.

This study aimed to explore (a) the experiences of peer practitioners working within Open Dialogue teams in the Open Dialogue: Development and Evaluation of a Social Intervention for Severe Mental Illness trial, and (b) the perspectives of non-peer Open Dialogue practitioners regarding peer involvement. Our further objectives were to understand the nature, degree and perceived impact of peer practitioner involvement in Open Dialogue.

A qualitative study was conducted using semi-structured interviews and joint interviews with peer practitioners (n = 9). Additionally, excerpts from 11 interviews and 4 focus groups (n = 18), in which non-peer practitioners discussed peer practitioners’ contributions in Open Dialogue, were analysed. Thematic analysis was employed to identify key themes.

Three themes were developed. The first focuses on the perceived influence of peer practitioners on Open Dialogue network meetings; the second explores the opportunities and challenges of working as a peer practitioner in Open Dialogue, while the third details the perceived impact of peer practitioners on team and organisational culture.

Open Dialogue’s emphasis on a flattened hierarchy facilitates the integration of peer practitioners, enabling them to contribute meaningfully to network meetings and team culture. Despite the overall positive experiences, peers still faced common challenges faced by those in other services, such as low pay and occasional instances of a compromised, flattened hierarchy.

There are critical gaps within implementation science concerning health equity, particularly for minoritised ethnic groups. Implementation framework adaptations are important to facilitate health equity, which is especially relevant for psychiatry due to ethnic inequities in mental health; however, the range of potential adaptations has yet to be synthesised.

This systematic scoping review aimed to identify and map the characteristics of adaptations to implementation frameworks for minority ethnic groups to improve health equity.

Bibliographic searches of the MEDLINE, Embase, PsycINFO and CINAHL databases were conducted, spanning the period from 2004 to February 2024 for descriptions of implementation frameworks adapted for minority ethnic groups. The characteristics of those meeting the criteria were narratively synthesised.

Of the 2947 papers screened, six met the eligibility criteria. Three different types of implementation frameworks were adapted across the six papers: evaluation, process and determinant frameworks. Most of the adaptations were made by expanding the original framework, and by integrating it with another model, theory or framework with an equity focus. The adaptations primarily focused on putting equity at the forefront of all stages of implementation from intervention selection to implementation sustainability. No studies measured the effectiveness of the adapted framework.

The findings demonstrate that implementation frameworks are modifiable, and different elements can be adapted according to the implementation framework type. This review provides a starting point for how researchers and healthcare providers can adapt existing implementation frameworks to promote health equity for minoritised groups across a range of healthcare settings.

Treatment guidelines recommend evidence-based psychological therapies for adults with intellectual disabilities with co-occurring anxiety or depression. No previous research has explored the effectiveness of these therapies in mainstream psychological therapy settings or outside specialist settings.

To evaluate the effectiveness of psychological therapies delivered in routine primary care settings for people with intellectual disability who are experiencing co-occurring depression or anxiety.

This study used linked electronic healthcare records of 2 048 542 adults who received a course of NHS Talking Therapies for anxiety and depression in England between 2012 and 2019 to build a retrospective, observational cohort of individuals with intellectual disability, matched 1:2 with individuals without intellectual disability. Logistic regressions were used to compare metrics of symptom improvement and deterioration used in the national programme, on the basis of depression and anxiety measures collected before and at the last attended therapy session.

The study included 6870 adults with intellectual disability and 2 041 672 adults without intellectual disability. In unadjusted analyses, symptoms improved on average for people with intellectual disability after a course of therapy, but these individuals experienced poorer outcomes compared with those without intellectual disability (reliable improvement 60.2% for people with intellectual disability v. 69.2% for people without intellectual disability, odds ratio 0.66, 95% CI 0.63–0.70; reliable deterioration 10.3% for people with intellectual disability v. 5.7% for those without intellectual disability, odds ratio 1.89, 95% CI 1.75–2.04). After propensity score matching, some differences were attenuated (reliable improvement, adjusted odds ratio 0.97, 95% CI 1.91–1.04), but some outcomes remained poorer for people with intellectual disability (reliable deterioration, adjusted odds ratio 1.28, 95% CI 1.16–1.42).

Evidence-based psychological therapies may be effective for adults with intellectual disability, but their outcomes may be similar to (for improvement and recovery) or poorer than (for deterioration) those for adults without intellectual disability. Future work should investigate the impact of adaptations of therapies for those with intellectual disability to make such interventions more effective and accessible for this population.

Women from minoritised ethnic communities experience inequalities in access, experience and outcomes of psychological therapy. Understanding the factors associated with these inequalities could inform improvements to mental health services.

To explore therapists’ experiences of providing treatment to women from minoritised ethnic communities, including insights on adaptations made at the delivery, content and wider organisation levels, and to gather suggestions about potential treatment improvements.

Semi-structured interviews were conducted with 13 therapists working in two National Health Service Talking Therapies for anxiety and depression services and who had experience of treating women from minoritised ethnic communities. Data were analysed using thematic analysis.

Three high-order themes were identified: incorporating ethnicity and culture in the delivery of psychological therapies, challenges associated with delivering therapeutic interventions to women from minoritised ethnic groups and improvements to services that could support better access, engagement and outcomes for women from minoritised ethnic groups.

Findings indicate that therapists viewed cultural adaptation and cultural sensitivity as important to the delivery of appropriate care for minoritised ethnic women. Challenges to appropriate care included limited service resources, communication and language barriers, stigma and existing access and engagement inequalities. Therapists suggested that, to deliver high-quality care and optimise outcomes, improvements are required in cultural sensitivity training, flexibility of service delivery, outreach work with communities to encourage uptake and reduce stigma, support for staff and workforce diversity.

Stigma of mental health conditions hinders recovery and well-being. The Honest, Open, Proud (HOP) program shows promise in reducing stigma but there is uncertainty about the feasibility of a randomized trial to evaluate a peer-delivered, individual adaptation of HOP for psychosis (Let's Talk).

A multi-site, Prospective Randomized Open Blinded Evaluation (PROBE) design, feasibility randomised controlled trial (RCT) comparing the peer-delivered intervention (Let's Talk) to treatment as usual (TAU). Follow-up was 2.5 and 6 months. Randomization was via a web-based system, with permuted blocks of random size. Up to 10 sessions of the intervention over 10 weeks were offered. The primary outcome was feasibility data (recruitment, retention, intervention attendance). Primary outcomes were analyzed by intention to treat. Safety outcomes were reported by as treated status. The study was prospectively registered: https://doi.org/10.1186/ISRCTN17197043.

149 patients were referred to the study and 70 were recruited. 35 were randomly assigned to intervention + TAU and 35 to TAU. Recruitment was 93% of the target sample size. Retention rate was high (81% at 2.5 months primary endpoint), and intervention attendance rate was high (83%). 21% of 33 patients in Let's talk + TAU had an adverse event and 16% of 37 patients in TAU. One serious adverse event (pre-randomization) was partially related and expected.

This is the first trial to show that it is feasible and safe to conduct a RCT of HOP adapted for people with psychosis and individual delivery. An adequately powered trial is required to provide robust evidence.

The nature of the pathway from conduct disorder (CD) in adolescence to antisocial behavior in adulthood has been debated and the role of certain mediators remains unclear. One perspective is that CD forms part of a general psychopathology dimension, playing a central role in the developmental trajectory. Impairment in reflective functioning (RF), i.e., the capacity to understand one's own and others' mental states, may relate to CD, psychopathology, and aggression. Here, we characterized the structure of psychopathology in adult male-offenders and its role, along with RF, in mediating the relationship between CD in their adolescence and current aggression.

A secondary analysis of pre-treatment data from 313 probation-supervised offenders was conducted, and measures of CD symptoms, general and specific psychopathology factors, RF, and aggression were evaluated through clinical interviews and questionnaires.

Confirmatory factor analyses indicated that a bifactor model best fitted the sample's psychopathology structure, including a general psychopathology factor (p factor) and five specific factors: internalizing, disinhibition, detachment, antagonism, and psychoticism. The structure of RF was fitted to the data using a one-factor model. According to our mediation model, CD significantly predicted the p factor, which was positively linked to RF impairments, resulting in increased aggression.

These findings highlight the critical role of a transdiagnostic approach provided by RF and general psychopathology in explaining the link between CD and aggression. Furthermore, they underscore the potential utility of treatments focusing on RF, such as mentalization-based treatment, in mitigating aggression in offenders with diverse psychopathologies.

A significant rise in mental health disorders was expected during the COVID-19 pandemic. However, referrals to mental health services dropped for several months before rising to pre-pandemic levels.

To identify trajectories of incidence and risk factors for common mental disorders among the general population during 14 months of the COVID-19 pandemic, to inform potential mental health service needs.

A cohort of 33 703 adults in England in the University College London COVID-19 Social Study provided data from March 2020 to May 2021. Growth mixture modelling was used to identify trajectories based on the probability of participants reporting symptoms of depression (Patient Health Questionnaire-9) or anxiety (Generalised Anxiety Disorder-7) in the clinical range, for each month. Sociodemographic and personality-related characteristics associated with each trajectory class were explored.

Five trajectory classes were identified for depression and anxiety. Participants in the largest class (62%) were very unlikely to report clinically significant symptom levels. Other trajectories represented participants with a high likelihood of clinically significant symptoms throughout, early clinically significant symptoms that reduced over time, clinically significant symptoms that emerged as the pandemic unfolded and a moderate likelihood of clinically significant symptoms throughout. Females, younger adults, carers, those with existing mental health diagnoses, those that socialised frequently pre-pandemic and those with higher neuroticism scores were more likely to experience depression or anxiety.

Nearly 40% of participants followed trajectories indicating risk of clinically significant symptoms of depression or anxiety. The identified risk factors could inform public health interventions to target individuals at risk in future health emergencies.

Psychological therapies can be effective in reducing symptoms of depression and anxiety in people living with dementia (PLWD). However, factors associated with better therapy outcomes in PLWD are currently unknown.

To investigate whether dementia-specific and non-dementia-specific factors are associated with therapy outcomes in PLWD.

National linked healthcare records were used to identify 1522 PLWD who attended psychological therapy services across England. Associations between various factors and therapy outcomes were explored.

People with frontotemporal dementia were more likely to experience reliable deterioration in depression/anxiety symptoms compared with people with vascular dementia (odds ratio 2.98, 95% CI 1.08–8.22; P = 0.03) or Alzheimer's disease (odds ratio 2.95, 95% CI 1.15–7.55; P = 0.03). Greater depression severity (reliable recovery: odds ratio 0.95, 95% CI 0.92–0.98, P < 0.001; reliable deterioration: odds ratio 1.73, 95% CI 1.04–2.90, P = 0.04), lower work and social functioning (recovery: odds ratio 0.98, 95% CI 0.96–0.99, P = 0.002), psychotropic medication use (recovery: odds ratio 0.67, 95% CI 0.51–0.90, P = 0.01), being of working age (recovery: odds ratio 2.03, 95% CI 1.10–3.73, P = 0.02) and fewer therapy sessions (recovery: odds ratio 1.12, 95% CI 1.09–1.16, P < 0.001) were associated with worse therapy outcomes in PLWD.

Dementia type was generally not associated with outcomes, whereas clinical factors were consistent with those identified for the general population. Additional support and adaptations may be required to improve therapy outcomes in PLWD, particularly in those who are younger and have more severe depression.

Self-harm is a significant problem in university students because of its association with emotional distress, physical harm, broader mental health issues and potential suicidality. Research suggests that fewer than half of students who have self-harmed seek professional help when at university.

This study aimed to explore the help-seeking journeys of university students who had engaged in self-harm, to identify perceived facilitators and barriers to securing both formal and informal support.

Participants comprised 12 students who had self-harmed during their university tenure. Engaging in two semi-structured interviews over the academic year, they shared insights into their help-seeking behaviours and proposed enhancements to local services. Data underwent reflexive thematic analysis within a critical realist framework.

The analysis identified four themes: ‘The initial university phase poses the greatest challenge’, ‘Perceived criteria for “valid” mental health problems’, ‘Evading external judgements, concerns and consequences’ and ‘The pivotal role of treatment options and flexibility in recovery’.

Students felt isolated and misunderstood, which amplified self-harming tendencies and diminished inclinations for help-seeking. A prevalent belief was that for self-harm to be deemed ‘valid’, it must manifest with a certain severity; however, concurrent fears existed around the ramifications of perceived excessive severity. Participants expressed a desire for streamlined pathways to mental health resources, encompassing both university and external mental health services. Insights from this study could guide future research and inform current service paradigms within academic and healthcare systems.

The COVID-19 pandemic has disproportionally affected the mental health of health and social care workers (HSCWs), with many experiencing symptoms of depression, anxiety and post-traumatic stress disorder. Psychological interventions have been offered via mental health services and in-house psychology teams, but their effectiveness in this context is not well documented.

To evaluate a stepped-care psychological support pathway for HSCWs from Homerton Healthcare Foundation Trust in London, which offered psychological first aid, evidence-based psychological therapies and group-based well-being workshops.

The service evaluation used a pre–post approach to assess depression, anxiety, functional impairment and post-traumatic stress disorder symptom change for those who attended sessions of psychological first aid, low- or high-intensity cognitive–behavioural therapy or a combination of these. In addition, the acceptability of the psychological first aid sessions and well-being workshops was explored via feedback data.

Across all interventions, statistically significant reductions of depression (d = 1.33), anxiety (d = 1.37) and functional impairment (d = 0.93) were observed, and these reductions were equivalent between the interventions, as well as the demographic and occupational differences between the HSCWs (ethnicity, staff group and redeployment status). HSCWs were highly satisfied with the psychological first aid and well-being workshops.

The evaluation supports the utility of evidence-based interventions delivered as part of a stepped-care pathway for HSCWs with common mental health problems in the context of the COVID-19 pandemic. Given the novel integration of psychological first aid within the stepped-care model as a step one intervention, replication and further testing in larger-scale studies is warranted.

The transition to university and resultant social support network disruption can be detrimental to the mental health of university students. As the need for mental health support is becoming increasingly prevalent in students, identification of factors associated with poorer outcomes is a priority. Changes in social functioning have a bi-directional relationship with mental health, however it is not clear how such measures may be related to effectiveness of psychological treatments.

Growth mixture models were estimated on a sample of 5221 students treated in routine mental health services to identify different trajectories of change in self-rated impairment in social leisure activities and close relationships during the course of treatment. Multinomial regression explored associations between trajectory classes and treatment outcomes.

Five trajectory classes were identified for social leisure activity impairment while three classes were identified for close relationship impairment. In both measures most students remained mildly impaired. Other trajectories included severe impairment with limited improvement, severe impairment with delayed improvement, and, in social leisure activities only, rapid improvement, and deterioration. Trajectories of improvement were associated with positive treatment outcomes while trajectories of worsening or stable severe impairment were associated with negative treatment outcomes.

Changes in social functioning impairment are associated with psychological treatment outcomes in students, suggesting that these changes may be associated with treatment effectiveness as well as recovery experiences. Future research should seek to establish whether a causal link exists to understand whether integrating social support within psychological treatment may bring additional benefit for students.

Depression is an important, potentially modifiable dementia risk factor. However, it is not known whether effective treatment of depression through psychological therapies is associated with reduced dementia incidence. The aim of this study was to investigate associations between reduction in depressive symptoms following psychological therapy and the subsequent incidence of dementia.

National psychological therapy data were linked with hospital records of dementia diagnosis for 119808 people aged 65+. Participants received a course of psychological therapy treatment in Improving Access to Psychological Therapies (IAPT) services between 2012 and 2019. Cox proportional hazards models were run to test associations between improvement in depression following psychological therapy and incidence of dementia diagnosis up to eight years later.

Improvements in depression following treatment were associated with reduced rates of dementia diagnosis up to 8 years later (HR = 0.88, 95% CI 0.83–0.94), after adjustment for key covariates. Strongest effects were observed for vascular dementia (HR = 0.86, 95% CI 0.77–0.97) compared with Alzheimer's disease (HR = 0.91, 95% CI 0.83–1.00).

Reliable improvement in depression across psychological therapy was associated with reduced incidence of future dementia. Results are consistent with at least two possibilities. Firstly, psychological interventions to improve symptoms of depression may have the potential to contribute to dementia risk reduction efforts. Secondly, psychological therapies may be less effective in people with underlying dementia pathology or they may be more likely to drop out of therapy (reverse causality). Tackling the under-representation of older people in psychological therapies and optimizing therapy outcomes is an important goal for future research.

Experience of crisis care may vary across different care models.

To explore the experience of care in standard care and ‘open dialogue’ (a peer-supported community service focused on open dialogue and involving social networks for adults with a recent mental health crisis) 3 months after a crisis.

We conducted semi-structured interviews with 11 participants (6 received open dialogue; 5 received treatment as usual (TAU)) in a feasibility study of open dialogue and analysed the data using a three-step inductive thematic analysis to identify themes that (a) were frequently endorsed and (b) represented the experiences of all participants.

Four themes emerged: (a) feeling able to rely on and access mental health services; (b) supportive and understanding family and friends; (c) having a choice and a voice; and (d) confusion and making sense of experiences. Generally, there was a divergence in experience across the two care models. Open dialogue participants often felt able to rely on and access services and involve their family and friends in their care. TAU participants described a need to rely on services and difficulty when it was not met, needing family and friends for support and wanting them to be more involved in their care. Some participants across both care models experienced confusion after a crisis and described benefits of sense-making.

Understanding crisis care experiences across different care models can inform service development in crisis and continuing mental healthcare services.

To determine: whether young adults (aged 18–24) not in education, employment or training (NEET) have different psychological treatment outcomes to other young adults; any socio-demographic or treatment-related moderators of differential outcomes; and whether service-level changes are associated with better outcomes for those who are NEET.

A cohort was formed of 20 293 young adults treated with psychological therapies in eight Improving Access to Psychological Therapies services. Pre-treatment characteristics, outcomes, and moderators of differential outcomes were compared for those who were and were not NEET. Associations between outcomes and the following were assessed for those that were NEET: missing fewer sessions, attending more sessions, having a recorded diagnosis, and waiting fewer days between referral and starting treatment.

Those who were NEET had worse outcomes: odds ratio (OR) [95% confidence interval (CI)] for reliable recovery = 0.68 (0.63–0.74), for deterioration = 1.41 (1.25–1.60), and for attrition = 1.31 (1.19–1.43). Ethnic minority participants that were NEET had better outcomes than those that were White and NEET. Living in deprived areas was associated with worse outcomes. The intensity of treatment (high or low) did not moderate outcomes, but having more sessions was associated with improved outcomes for those that were NEET: odds (per one-session increase) of reliable recovery = 1.10 (1.08–1.12), deterioration = 0.94 (0.91–0.98), and attrition = 0.68 (0.66–0.71).

Earlier treatment, supporting those that are NEET to attend sessions, and in particular, offering them more sessions before ending treatment might be effective in improving clinical outcomes. Additional support when working with White young adults that are NEET and those in more deprived areas may also be important.

Previous qualitative research suggests that university students feel that current service provision does not meet their needs. Exploring the reasons for this may help to promote service change, encourage the uptake of care, improve outcomes and increase satisfaction within university services.

This study aimed to improve the understanding of how students experience the process of accessing and using mental health support, barriers and facilitators to treatment, and how students would adapt provision to improve experiences.

Semi-structured interviews were conducted with 16 full-time students who had used mental health services at university. Data were analysed using thematic analysis.

Five higher-order themes were identified: personalisation and informed choice, simplifying the process, feeling abandoned ignored or invisible, stigma, and superiority of private and external services. Sixteen subthemes were identified within these themes.

Findings indicate that access to mental health support should be simplified, with collaboration across university and external health and care services, to prevent students feeling lost or abandoned when seeking care. An inclusive approach to support access and provision of services for all presentations of mental health problems should be developed.

This study aimed to investigate general factors associated with prognosis regardless of the type of treatment received, for adults with depression in primary care.

We searched Medline, Embase, PsycINFO and Cochrane Central (inception to 12/01/2020) for RCTs that included the most commonly used comprehensive measure of depressive and anxiety disorder symptoms and diagnoses, in primary care depression RCTs (the Revised Clinical Interview Schedule: CIS-R). Two-stage random-effects meta-analyses were conducted.

Twelve (n = 6024) of thirteen eligible studies (n = 6175) provided individual patient data. There was a 31% (95%CI: 25 to 37) difference in depressive symptoms at 3–4 months per standard deviation increase in baseline depressive symptoms. Four additional factors: the duration of anxiety; duration of depression; comorbid panic disorder; and a history of antidepressant treatment were also independently associated with poorer prognosis. There was evidence that the difference in prognosis when these factors were combined could be of clinical importance. Adding these variables improved the amount of variance explained in 3–4 month depressive symptoms from 16% using depressive symptom severity alone to 27%. Risk of bias (assessed with QUIPS) was low in all studies and quality (assessed with GRADE) was high. Sensitivity analyses did not alter our conclusions.

When adults seek treatment for depression clinicians should routinely assess for the duration of anxiety, duration of depression, comorbid panic disorder, and a history of antidepressant treatment alongside depressive symptom severity. This could provide clinicians and patients with useful and desired information to elucidate prognosis and aid the clinical management of depression.

Real-life decisions are often complex because they involve making sequential choices that constrain future options. We have previously shown that to render such multi-step decisions manageable, people ‘prune’ (i.e. selectively disregard) branches of decision trees that contain negative outcomes. We have theorized that sub-optimal pruning contributes to depression by promoting an oversampling of branches that result in unsavoury outcomes, which results in a negatively-biased valuation of the world. However, no study has tested this theory in depressed individuals.

Thirty unmedicated depressed and 31 healthy participants were administered a sequential reinforcement-based decision-making task to determine pruning behaviours, and completed measures of depression and anxiety. Computational, Bayesian and frequentist analyses examined group differences in task performance and relationships between pruning and depressive symptoms.

Consistent with prior findings, participants robustly pruned branches of decision trees that began with large losses, regardless of the potential utility of those branches. However, there was no group difference in pruning behaviours. Further, there was no relationship between pruning and levels of depression/anxiety.

We found no evidence that sub-optimal pruning is evident in depression. Future research could determine whether maladaptive pruning behaviours are observable in specific sub-groups of depressed patients (e.g. in treatment-resistant individuals), or whether misuse of other heuristics may contribute to depression.

1. (1) How changes to treatment-delivery factors are associated with IAPT patient outcomes.

2. (2) The link between clinical practice and potential service performance.

3. (3) How analysing routinely collected data can be used to inform service improvement.