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Can Trauma Cause Schizophrenia?

DSC04550My dad killed my mom, Sara, he killed my mom.  Right in front of me while I lay under the bed.  He killed her, Sara, and then he left. I never saw him again.

My first job out of graduate school was working with an Assertive Community Treatment team.  It’s a fascinating program sometimes referred to as a “hospital without walls.” The team is made up of a psychiatrist, psychiatric nurses, mental health professionals (like me) and a peer support paraprofessional, who has a shared history with the clients: adults with severe, persistent mental illness.  In addition, we were a specialized team who only treated clients who additionally had substance dependence diagnoses.

We meet clients in their homes, ideally a few times a week for medication administration, life skills training, help with doctors’ visits and case management.  This level of support in the community helps clients continue to live in the community and has been shown to reduce arrests, emergency room visits and psychiatric hospitalizations, which are common measures of the level of functioning.

One thing that struck me was that almost all the client endorsed severe childhood trauma.  Some of them not only endorsed it, but appeared to be stuck in it, describing over and over again watching family members die in front of them or being harmed by a caregiver. Despite this, we did not formally screen for abuse experiences or symptoms upon intake and usually the information came up later.

Though both laypeople and the professional community generally think of schizophrenia as being highly genetic in nature, environmental stress plays a substantial role, though what role is not completely clear.  One thought is that stress activates a genetic predisposition to schizophrenia.  But there are a lot of types of stress and we know that traumatic stress has a different kind of impact than daily stress on people in general—but does this mean it interacts, or even causes schizophrenia?

Schizophrenia and Trauma

There is a lot of research noting the high prevalence of trauma in psychotic patients, and there is also a high incidence of psychotic symptoms in veterans with PTSD (40%). It’s clear that there is some kind of a relationship there, but is the traditional view, that exposure to stress “unlocks” some genetic timebomb that is waiting in some people’s minds? Or is it in fact more causal than that?

Is Trauma the Key?

In a comprehensive 2005 literature review, John Read, et al argues that child abuse does in fact cause schizophrenia, or at least hallucinations and delusions. It’s every difficult to argue causation in retrospective analysis, but it has been done, such as in the relationships between smoking and lung cancer, and not wearing a seatbelt and dying in a car accident. Basically you need a huge population so that you can really look at both the “exposed/unexposed” populations (smoking/not smoking and seatbelt wearing/unbelted) and the “outcome/no outcome” (lung cancer/no lung cancer and died/survived) populations and control for many confounding variables, which in this case particularly means genetics.

There is such a huge population, but there hasn’t been enough research yet.  One thing that is particularly interesting though is recent discoveries about the neuromechanisms behind both trauma and schizophrenia.  There are several similarities in how brains of both those with PTSD and those with schizophrenia differ from the brains of neurotypical individuals. Namely:

  • The hypothalamic-adrenal-pituitary axis is over-reactive
  • There are similar structural changes, particularly “hippocampal damage, cerebral atrophy, ventricular enlargement and reversed cerebral asymmetry.”
  • There are abnormalities in levels of serotonin, dopamine and norepinephrine

Trauma and Psychotic Symptoms

Viewed through a trauma lens, I have to ask whether folks have schizophrenia, or whether they have misdiagnosed complex trauma, which can feature both delusions (often in the form of paranoia) and hallucinations (sometimes in the form of parts talking to each other).  It wouldn’t be the first time schizophrenia has been misdiagnosed: Schizophrenia is diagnosed far more often in African-Americans than in any other racial group, and evidence suggests that when evaluators use standardized measures, these differences disappear and that the misdiagnosis is due to racial prejudice.

Severe trauma is known to cause psychotic symptoms and we know some things about those.

  • Several studies found a correlation between the severity of abuse and severity of psychotic symptoms.
  • Trauma is more often associated with the positive symptoms of hallucinations and delusions and not so much with negative symptoms of flat affect, isolation, word poverty, etc.
  • The content of trauma-associated hallucinations is often of a flashback quality or symbolic with respect to the nature of the abuse.

Schizophrenia is a real disease, but it’s also a complicated and sometimes over diagnosed one.  Because there is such a strong association between trauma and psychotic symptoms, it is crucial to take a trauma history while diagnosing and even while developing treatment plans for those who have confirmed (by which I mean standardized, trauma-informed and culturally competent) diagnosis.  And there needs to be research to determine whether trauma therapy for some individuals with schizophrenia could be helpful.

Can Trauma Cause Schizophrenia?

Sara Staggs, LICSW, MPH

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APA Reference
Staggs, S. (2014). Can Trauma Cause Schizophrenia?. Psych Central. Retrieved on October 26, 2020, from


Last updated: 7 Oct 2014
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