Objective Increasing evidence suggests experiences of childhood trauma may be causally related to the development of hallucinations. Cognitive theories of psychosis suggest post‐traumatic intrusions to be a primary mechanism in this relationship. These theories predict that the content of hallucinations will be related to traumatic experiences; however, few studies have investigated this. This study examined the relationship between childhood trauma, the content of hallucinations, and the content of post‐traumatic intrusions in a sample with first‐episode psychosis. Methods Sixty‐six young people aged 15–25 experiencing a first episode of psychosis were recruited from an early intervention service. Participants completed assessments of traumatic experiences, hallucination content, and post‐traumatic intrusion content using a systematic coding frame. The coding frame assessed for three types of relationships between traumatic experiences, the content of hallucinations, and the content of post‐traumatic intrusions: direct relationships (hallucination content exactly matching the trauma/intrusion), thematic relationships (hallucinations with the same themes as the trauma/intrusion), and no relationship (hallucination and trauma/intrusion content unrelated). Results Of those people who reported trauma and hallucinations (n = 36), 22 of these (61%) experienced post‐traumatic intrusions, and of these, 16 (73%) experienced hallucinations that were directly or thematically related to their post‐traumatic intrusions. Twelve people experienced hallucination content directly related to their trauma, six of whom (50%) also had intrusions relating to the same traumatic event as their hallucinations. Conclusions The finding that some people experience hallucinations and post‐traumatic intrusions relating to the same traumatic event supports theories proposing a continuum of memory intrusion fragmentation. These results indicate that early intervention services for young people with psychosis should provide assessment and intervention for trauma and PTSD and should consider the impact of past traumatic events on the content of current hallucinatory experience. Practitioner points Trauma and post‐traumatic stress disorder should be assessed in those experiencing a first episode of psychosis. Interventions for trauma should be offered in early intervention for psychosis services. In a notable proportion of people, hallucination content is related to traumatic experiences. Clinical assessment and formulation of hallucinations requires consideration of how past traumatic events may be contributing to hallucinatory experience. It is important for clinicians to have an understanding of the phenomenological differences between hallucinations and post‐traumatic intrusions when conducting clinical assessments with people with comorbid psychosis and PTSD.

Background: Evidence based treatment interventions for young people with first-episode psychosis (FEP) and trauma histories is lacking. Although case formulation (CF) has been widely regarded in cognitive behavioural therapy manuals as beneficial, there is limited empirical research examining how clients and therapists experience the process. Aim: This study aimed to explore young people’s reactions to CF in treatment for PTSD (post-traumatic stress disorder) and FEP. Method: Semi-structured interviews were conducted with three participants (aged 19–20) with FEP and PTSD and their therapists, after they had completed a trauma-focused treatment program with a CF component. Transcripts were analysed using an interpretative phenomenological approach and themes were derived. Results: Two themes related to participants’ experiences were identified from the analysis: (1) Developing Insight; (2) A challenging experience; and two themes from the therapists: (1) Doing the case formulation; (2) Value of case formulation. Participants and therapists reported benefits in making connections between current symptoms and past trauma. Participants viewed the process as challenging. Conclusion: Results suggest a potential discrepancy between the experience of the case formulation process for clients and therapists.

Aim Interpersonal trauma exposures are associated with anxiety, depression, and substance use in youth populations (aged 12–25 years). This meta‐analysis reports on the efficacy of psychological interventions on these symptom domains in addition to post‐traumatic stress. Methods Following PRISMA guidelines, a search of electronic databases was performed for randomized controlled trials (RCTs) assessing interventions for young people following interpersonal trauma exposure. Risk of bias was assessed using the Cochrane Risk of Bias tool. Data were analysed using random‐effects meta‐analyses. Results Of the 4832 records screened, 78 studies were reviewed, and 10 RCTs, involving 679 participants (mean age 15.6 years), were analysed. There was a large pooled effect size for post‐traumatic stress (7 studies, g = 1.43, 95% CI [0.37, 2.15], p = .002) and substance use (2 studies, g = 0.70, 95% CI [−0.11, 1.22], p < .001) and small effect sizes for anxiety (4 studies, g = 0.30, 95% CI [0.10, 0.49], p = .003), and trend‐level effect for depression (10 studies, g = 0.27, 95% CI [0.00, 0.54], p = .052). Heterogeneity was significant for post‐traumatic stress and moderate for depression. Conclusions High‐quality RCTs of psychological interventions for anxiety, depression, substance use, and post‐traumatic stress symptoms in young people exposed to interpersonal trauma are scarce. While available studies show either statistically significant or trend‐level efficacy for psychological interventions in reducing these symptoms, wide confidence intervals, heterogeneity and small sample size mean that results need to be interpreted with caution.