Comorbid mood disorder increases suicide risk in schizophrenia patients
MedWire News: The presence of a previous or co-existing mood disorder is associated with a significantly increased risk for suicide in patients with schizophrenia, research shows.
Understanding factors associated with suicide risk in schizophrenia is important as patients with the mental health disorder are around 12 times more likely to take their own lives than the general population, explain Johan Reutfors (Karolinska Institute, Stockholm, Sweden) and colleagues.
"However, as most previous studies in this field have assessed the risk of suicide in schizophrenia in relation to specific symptoms, it remains to be better understood how suicide risk relates to the diagnostic profile of patients with schizophrenia," they add.
The team therefore studied data on 4000 patients, aged less than 65 years, who were diagnosed with schizophrenia, schizophreniform, or schizoaffective disorder in Stockholm County between 1984 and 2000.
Of these, 84 committed suicide within 5 years of diagnosis.
The team compared the diagnostic profiles of these patients with those of 84 age- and date of diagnosis-matched schizophrenia spectrum disorder patients from the same cohort who did not take their own lives.
The researchers found that the presence of a comorbid DSM-IV mood disorder, such as bipolar disorder or depression, was associated with a significantly increased risk for suicide. Indeed, unadjusted analysis revealed that patients with schizophrenia who had a previous or co-existing mood disorder were 3.4 times more likely to commit suicide than schizophrenia patients without a mood disorder.
This risk fell only slightly, to an odds ratio of 3.3, after accounting for gender, level of education, country of birth, and age at symptom onset, the researchers note in the journal Schizophrenia Research.
"In this population-based case-control study among patients with a clinical ICD-schizophrenia spectrum diagnosis, we found that a DSM-IV mood disorder diagnosis was associated with a more than three-fold increased risk of suicide within 5 years from diagnosis," Reutfors and team conclude.
They add: "This result calls attention to the importance of continuous diagnostic evaluation when assessing the suicide risk in patients with schizophrenia spectrum disorder."
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By Mark Cowen