Very-late-onset schizophrenia linked to particularly high mortality risk
medwireNews: Patients with very-late-onset schizophrenia-like psychosis (VLOSLP) have an increased risk of death compared with both the general population and patients with schizophrenia diagnosed earlier in life, Finnish study findings indicate.
The risk is particularly high in men and is most likely due to increased physical comorbidities and susceptibility to accidents, report Tiina Talaslahti (Helsinki University Central Hospital) and colleagues in the International Journal of Geriatric Psychiatry.
The researchers calculated standardised mortality ratios (SMRs) relative to the general Finnish population for 918 patients with VLOSLP (defined as disease onset at 60 years or older) and for 6142 similar-aged patients with onset of schizophrenia before the age of 60 years.
During 10 years of follow-up, 59% of patients with VLOSLP and 55% of those with earlier disease onset died. Patients with VLOSLP were significantly older at the time of death than those with earlier onset disease (78.2 vs 76.0 years) and were more likely to have circulatory diseases, dementia and alcoholism.
Talaslahti and team found that mortality was five times higher in the VLOSLP patients than in the Finnish population (SMR=5.02) and was three times higher in the patients with earlier onset schizophrenia (SMR=2.93).
There were clear differences according to gender, with men in the VLOSLP group having a SMR of 8.31 compared with the general population, versus an SMR of 4.21 for affected women. In the earlier onset group, the respective SMRs were 2.91 and 2.94.
As in the general population, circulatory diseases were the most common cause of death in both the VLOSLP and earlier onset group, and appeared to affect both groups to a similar degree with SMRs of 2.83 and 2.26, respectively.
By contrast, unnatural causes of death, namely accidents and violence, occurred nearly 34 times more often (SMR=33.74) among VLOSLP patients than among the general age-matched population. Unnatural causes of death also had the highest SMR in the earlier onset group, at 8.93.
The SMRs for respiratory diseases, dementia and neoplasms were also increased in both groups, ranging from 1.75 to 14.46, with ratios in the VLOSLP group at least twice as high as those in the earlier onset group.
Despite the differences in SMRs between the groups, a within-sample comparison showed that the risk of death during follow-up was only 16% higher for the patients with VLOSLP compared with those with earlier onset disease. However, this was independent of gender, age, physical illnesses, alcohol dependence and use of antipsychotic medication at baseline.
“Therefore, it seems that schizophrenia itself increases mortality equally in old age regardless of the time of onset of illness”, Talaslahti and co-authors remark.
They conclude that “[t]argeted clinical interventions with effective collaboration between psychiatry and primary and specialist-level somatic care are crucial” to reduce the excess mortality observed in elderly patients with schizophrenia.
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By Laura Cowen, medwireNews Reporter