There is strong evidence that people with mental disorders have a considerably shorter life expectancy (10.1 years on average) compared to the general population (Walker et al., 2015), with recent studies showing a higher relative risk of mortality, compared with other studies focused on previous periods (before 1970) (Walker et al., 2015). These findings would suggest that the relative risk of dying for people with mental disorders is increasing instead of decreasing. In other words, it seems that recent improvements in the life expectancy of the general population might not be applicable (at least to the same extent) to persons suffering from mental disorders (Plana-Ripoll et al., 2020b). This gap could be considered as an indicator of the effectiveness of health and preventive policies (Wahlbeck et al., 2011).

Despite the fact that suicide rates are especially higher among people with mental disorders compared with those without a mental disorder, chronic somatic illnesses are the main causes for mortality, representing a proportion of all causes of death up to ten times higher than suicides (Kisely et al., 2005). Cardiovascular diseases (Correll et al., 2017; Lawrence et al., 2010), type II diabetes (Nuevo et al., 2011), and respiratory and infectious diseases (acquired immunodeficiency syndrome, hepatitis, tuberculosis, COVID-19) (Melo et al., 2022; Teixeira et al., 2021) are among the main natural causes for death in these patients.

The majority of studies on mortality associated with mental disorders used data from Nordic countries, where registers have been open to scientists for decades (Mortensen and Juel, 1993), but also from countries such as US, United Kingdom, Australia, Japan, China, the Netherland or Germany (Walker et al., 2015). Data on excess mortality associated with mental disorders in Southern Europe is still scare. Several studies have been published with data from Italy (e.g., D'Avanzo et al., 2003; Grigoletti et al., 2009). In Spain, a recent study reported the excess mortality associated with schizophrenic spectrum disorders using data from a community-care based and in-patient register (Moreno-Küstner et al., 2021). However, there is still no data on the mortality associated with other mental diagnoses, such as anxiety disorders, in Southern Europe. This is the first comprehensive study analysing excess mortality associated with several mental disorders using inpatient and outpatient health registers from the region of Catalonia, Spain. Catalonia has a public health system that offers universal healthcare to its inhabitants, with computerised registers containing health data which are currently being open to the scientific community to facilitate transfer of results and promote the return to society. Since the risk for excess mortality in people with mental disorders relies on individual, health system and socio-environmental risk factors (Liu et al., 2017), evidence from this specific region can provide valuable information that could contribute to the public health agenda to reduce the excess mortality in this population.

The present study aims to: a) estimate mortality rate ratios associated with mental disorders using data from the health registers of the region of Catalonia (Spain); b) analyse if these estimates are different in males and females, and in different age groups; and c) study the main mortality causes (natural causes, suicide, other unnatural causes).