There is a large mortality gap between patients with a non-affective psychotic disorder (NAPD) and the general population.

To assess whether mortality risks vary for different death causes according to duration since diagnosis and age in a large sample of NAPD patients.

To get insight into the risk of specific death causes along the treatment trajectory, important for interventions that are tailored to the patients' risk profile.

Data of NAPD patients (n=12,580) from three Dutch psychiatric registers were linked to the registers of Statistics Netherlands and compared to personally matched controls (n=124,143). Death rates were analysed by duration since the date of diagnosis of the (matched) patient and age using Poisson regression.

Among patients, the rates of all-cause death decreased with longer duration. This was explained by lower suicide rates. E.g., among those aged 40-60 years, the rate ratios (RRs) of suicide during 2-5 and >5 years compared to the early years after diagnosis were 0.52 and 0.46 (P=0.002). Compared with controls, patients experienced higher rates of natural death causes during all stages and in all age categories: RRs 2.35-5.04, P <0.05. No increase in these RRs for patients compared to controls with increasing duration or increasing age was found.

The high risk of natural death causes among NAPD patients is not (only) an effect of accumulating risks induced by the chronic nature of the disorder and/or antipsychotic treatment, but is already present during the early stages of the treatment and at young age.