Trauma Linked to Significant, Persistent Psychosis Risk

Liam Davenport

March 31, 2016

MADRID — Individuals diagnosed with traumatic stress disorder have a significant and persistent risk of subsequently developing schizophrenia or bipolar disorder, a large-scale registry study indicates.

Niels Okkels, MD, Department of Affective Disorders, Aarhus University Hospital Risskov, in Denmark, found that there was an eightfold increased risk of developing schizophrenia and a fourfold increased risk for bipolar disorder 5 years after experiencing trauma.

His results also showed that immediately following exposure to trauma, the risk for a psychotic diagnosis was as much as 20-fold higher.

The findings were presented here at the European Psychiatric Association (EPA) 24th Congress.

Pragmatic Conclusion

Dr Okkels believes that this initially very high risk "may at least partly be explained by bias due to contact to the healthcare system, which increases the likelihood of being diagnosed."

He also told Medscape Medical News that the symptoms of traumatic stress disorder may overlap with those of psychosis and mood disorders.

"The symptom overlap may be especially large in the period immediately following the trauma diagnosis. This increases the risk of misdiagnosis and risk of referral bias," he said.

Dr Okkels stressed that the "strongest argument" against the idea that these biases account for all of the increased risk for severe mental illness is that the risk persists for more than 5 years after a diagnosis of traumatic stress disorder. This suggests that researchers should take a long perspective when examining associations.

Dr Okkels also pointed out that the study focused on traumatic stress diagnosis. "My study does not say anything, really, about the traumatic experiences that are behind the traumatic stress diagnosis," he said.

The conclusion is, therefore, "very pragmatic, because what we see here is that persons given a diagnosis of traumatic stress disorder are at high risk of later receiving a more severe diagnosis."

Although previous studies have demonstrated that there is a high degree of comorbidity between trauma and both schizophrenia and bipolar disorder, relatively little is known about their etiologic relationship.

Dr Okkels linked the Danish Civil Registration System to the Psychiatric Central Register to identify all cases over a 20-year period in which acute stress reaction (ASR) and traumatic stress disorder were associated with diagnoses of schizophrenia, schizoaffective disorder, and bipolar affective disorder as the outcomes.

From a cohort of 1,005,021 people identified from the civil register, 3168 cases of ASR and 1203 cases of traumatic stress disorder were identified. This showed that the incidence of the overall diagnosis of traumatic stress disorder increased from 0.6% in 1996 to 6.0% in 2012. It was higher in women, and the incidence peaked for persons in early adulthood.

Analysis revealed that the incidence risk ratio (IRR) of schizophrenia was initially extremely high following a diagnosis of traumatic stress and then steadily decreased, at 19.93 at 0-1 year after diagnosis, 8.30 at 1-2 years, 5.83 at 2-5 years, and 3.80 at more than 5 years.

A similar pattern was seen for schizoaffective disorder, with at IRR of 20.93 at 0-1 year following a traumatic stress diagnosis and decreased steadily to 2.34 more than 5 years after diagnosis. For bipolar disorder, the equivalent IRRs were 17.99 and 4.22, respectively.

Dr Okkels pointed out that the relationship between traumatic stress disorder and psychosis is "really complex." He noted that after his presentation, a member of the audience asked why he did not reverse the study.

"This is a good question, because it may be that severe mental illness increases the risk of traumatic stress disorders," he said.

Warrants a Closer Look

However, Maria Paz García-Portilla Gonzalez, MD, PhD, Department of Psychiatry and Centro de Investigación Biomédica en Red de Salud Mental, University of Oviedo, Spain, who chaired the session, said that that is beside the point.

"I think this is just an association, and this is important because many times, we don't give enough importance to this problem of trauma in people, and now, with these data, we have to," she told Medscape Medical News.

Dr García-Portilla Gonzalez said that we have to "take care" and consider trauma as a potential risk factor for psychosis. "We know this very well from child abuse, we have seen it in suicide, and it has been very well demonstrated in depression," she noted.

She added that the short-term risk identified in the study "is very important" and that we have to "look deeper into this issue."

Dr Okkels and Dr Garcia-Portilla Gonzalez report no relevant financial relationships.

European Psychiatric Association (EPA) 24th Congress: Presented March 13, 2016.


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