Psychiatric morbidity and suicidal behaviour in psoriasis: a primary care cohort study

Abstract

Background: Psychological distress among people with psoriasis may lead to elevated risks of suicide and nonfatal self-harm.

Objectives: To investigate psychiatric comorbidity, psychotropic medication prescribing and risk of suicidality in people with psoriasis.

Methods: A cohort of patients with psoriasis (1998-2014) was delineated using the Clinical Practice Research Datalink, with linkage to Hospital Episode Statistics and Office for National Statistics mortality records. Each patient with psoriasis was matched with up to 20 patients without psoriasis on age, sex and general practice. A stratified Cox regression model was used to estimate the hazard ratios (HRs) for suicide or nonfatal self-harm risks adjusted for socioeconomic status.

Results: At baseline, among 56 961 and 876 919 patients with and without psoriasis, higher prevalence for histories of alcohol misuse, bipolar disorder, depression, anxiety disorders, self-harm and psychotropic drug prescription were observed. The deprivation-adjusted HR indicated lower suicide risk in people with psoriasis [HR 0·59, 95% confidence interval (CI) 0·41-0·85]. The risk of suicide varied according to age: it was lower in people with psoriasis diagnosed at ≥ 40 years (HR 0·38, 95% CI 0·21-0·66), whereas there was no difference in risk of suicide in people with psoriasis diagnosed before age 40 years (HR 0·92, 95% CI 0·58-1·46). Conversely, there was a small increased risk for self-harm (HR 1·15, 95% CI 1·04-1·27) associated with psoriasis.

Conclusions: The prevalence of mental illness was raised in people with psoriasis, and this may lead to a greater risk of self-harm. Nevertheless, having psoriasis does not appear to be associated with an increased risk of suicide. Healthcare professionals caring for patients with psoriasis should continue to monitor and tackle effectively the psychological needs of these individuals.