It is known that people with personality disorders die prematurely. This may be connected to high levels of co-morbidity with other psychiatric disorders. To test whether mortality was independent, deaths were examined in a 31-year cohort study of anxious and depressed patients (Nottingham Study of Neurotic Disorder) who also had their personality status assessed at baseline. The severity of personality disturbance was assessed using a method previously used to separate personality disorders into ICD-11 categories. Over the follow-up period, 71 of the cohort of 201 patients had died. Age at death was 5.1 (M) and 5.2 (F) years younger in those with personality disorder compared with no personality disorder, but after adjusting for age at randomization and clinical diagnosis at baseline, these differences reduced to 1.5 (M) and 1.6 (F) years. The longevity of the group was 12 to 18 years less than the general population (p < 0.0001), reinforcing previous findings of premature mortality in common mental illness. Analysis of causes of death showed no meaningful differences in personality groups. The hypothesis that premature death in personality disturbance is independent of mental health status was not supported in this study, despite other evidence from this cohort that general clinical outcome is worse in those with personality disorder. © 2019 John Wiley & Sons, Ltd.