If you hear “psychosis”, what do you think of? Many people believe psychosis is a brain disorder and only hear about it on the news in relation to a violent or traumatic crime.In fact, psychosis is not a diagnosis. It’s a collection of symptoms that affect your mind and how you interpret the world. People experiencing psychosis are more likely to be a risk to themselves than others. And we now know trauma can increase your risk of developing psychosis. A growing body of research shows using “talk therapy” to treat post-traumatic stress disorder (PTSD) – a psychiatric condition some people develop after experiencing trauma – can also effectively treat psychosis.But we still don’t routinely assess and treat trauma in people with psychosis. Here’s why we should.What is psychosis?People with psychosis may experience hallucinations (seeing, hearing, smelling, tasting or feeling things that are not present) and delusions (strongly held beliefs that are not shared by others, often rooted in fears of harm from others or paranoia). For some, psychosis can be a one-off episode, in response to acute stress. Others may develop recurrent or persistent difficulties, and receive a diagnosis of schizophrenia or bipolar disorder. Read more: Lessons from Bondi Junction attack show what we really need from schizophrenia care Psychosis can affect thinking skills, so you may struggle to concentrate, or have jumbled thoughts and speech. And it can affect emotions and motivation, making you feel flat and isolated, or triggering mood swings. How can trauma trigger psychosis?People who have experienced traumatic life events, particularly in childhood, are three times more likely to go on and develop psychosis than those who don’t. The increased risk is comparable to smoking and later developing lung cancer.Traumatic events can shape what people do to manage or survive threatening situations. For example, some may develop an oversensitive alarm system to threat (hypervigilance) while others may “space out” or cut off from the experience (dissociation). Read more: ‘Wait with me until it’s over’: what teens want you to know about dissociation Memories of traumatic events can be very intrusive and vivid, leaving people feeling like the past is happening in the present.Trauma can also affect how people see themselves, the world and others. This may lead to negative beliefs, such as “I am bad or digusting” or “bad things always happen to me” or “other people can’t be trusted” and “they’re out to get me”. These symptoms are central to PTSD, but we now also recognise they may overlap with, and contribute to, experiences of psychosis including hallucinations and delusions.Research is still disentangling how these behaviours, beliefs and memories may lead to psychosis. It may be that PTSD makes the brain so threat-focused, it alters how people experience reality and what they believe. So how would therapy help?Medication is often ineffective at treating overlapping PTSD and psychosis symptoms such as fragmented memory, hypervigilance and dissociation.Recent research (which some of us were involved in) shows how psychological therapy that focuses on treating PTSD can also improve psychotic symptoms, such as delusions, paranoia and hallucinations.The treatment is called trauma-focused cognitive behavioural therapy (CBT) for psychosis, and builds on other therapies.In general, CBT focuses on reframing unhelpful thoughts and behaviours. As a standard technique for treating PTSD, a therapist will help the person revisit and talk through distressing memories in a structured way.For example, they may help someone who has survived a traumatic event and thinks “it was my fault” to develop an alternative narrative, such as “I did what I could at the time”. Trauma-focused CBT for psychosis adapts these techniques and integrates them with strategies to also target psychosis symptoms. This could include how to cope with and make sense of hallucinations and delusions. It involves a longer course of therapy than usually recommended for people without psychosis, typically 26 sessions delivered over 6–12 months.The research shows this kind of CBT – which targets both PTSD and psychosis – can help people understand the effects of trauma and learn how to cope better. It can make memories less intrusive, vivid and fragmented, and reduce other symptoms such as experiencing voices, visions, paranoia, nightmares and dissociation.There have been some concerns that memory reprocessing techniques that are helpful for PTSD could make problems worse in people with psychosis. But research shows while PTSD symptoms can increase, this a temporary and common part of the therapy process, and doesn’t affect people’s long-term recovery.The recent research also supports this, showing there was no increase in hopsitalisations or suicide attempts among people with psychosis who had this therapy.What still needs to changeFor more than a decade, international and Australian guidelines for managing psychosis have highlighted the need to assess and treat people with psychosis for PTSD.However, barriers to adopting trauma-focused therapy for psychosis still remain, including clinicians’ misconceptions about its credibility and safety as well as a lack of confidence in delivering it. At the system level, health-care professionals have also identified workload pressure and inadequate resources as key challenges.So we need to facilitate resources, training, and supervision in trauma-focused therapy for psychosis for mental health clinicians. The inextricable link between trauma and psychosis has been overlooked for too long. But we now have the evidence and the tools to fix this.We would like to acknowledge the contribution of Amy Hardy in preparing this article.If this article has raised issues for you, or if you’re concerned about someone you know, call Lifeline on 13 11 14. In an emergency, call triple zero.Leila Jameel has worked on clinical trials funded by the Australian government National Health and Medical Research Council and National Institute of Health and Social Care Research in the UK. She also previously received a research council scholarship to fund her postgraduate training in the UK, from the Economic and Social Research Council.She is a Clinical Psychologist and Researcher at Swinburne University of Technology, and is also affiliated with King's College London, UK. She worked and collaborated with the authors and investigators of the Peter (2026) STAR trial mentioned in the article, including as a Clinical Psychologist seeing patients on the STAR trial of TF-CBTp. However, she was not directly involved in the conception of the trial nor the write up of this publication. She is listed as a member of the STAR Group on the publication as a pub-med indexed collaborator of the article. Anh Do is building a collaboration with the STAR research team as part of her PhD project at Swinburne University of Technology, in which she investigates the need for and the mechanistic understanding of trauma-focused therapy for psychosis.Rachel Brand is a chief investigator on a current Australian Government National Health and Medical Research Council funded clinical trial of psychological therapies for auditory verbal hallucinations. She is a clinical psychologist in private practice with adjunct academic appointments at both Swinburne University of Technology and The University of the Sunshine Coast. She was involved in the STAR trial mentioned in the article as a external assessor of therapy fidelity, but was not involved in the conception of the trial or the write up of this publication. Dr Rachel Brand has previously collaborated with the authors of the article on other research publications unrelated to this trial.