Differences in psychiatric comorbidity patterns in patients diagnosed with chronic stress-induced exhaustion disorder and depression - A cohort study in the total population of Region Stockholm.

The high prevalence of stress-related disorders and depression underscores the urgent need to unravel their impact on individual well-being. This study aim to investigate common psychiatric and stress-related diagnoses, along with postviral fatigue, in individuals with prior stress-induced exhaustion disorder (SED) and prior depression compared to those without prior SED or depression, and to study whether the psychiatric comorbidity patterns differ. The study includes individuals in Region Stockholm who, in 2011, did not have a diagnosis of SED or depression. ICD-10 diagnosis of SED, depression, or both, recorded in 2012-2013, were compared to individuals without prior SED or depression in a cohort (n = 1,362,886), aged 18 to 65. Odds ratios (OR) with 99 % confidence intervals, adjusted for age and neighborhood socioeconomic status, were calculated for psychiatric disorders and post-viral fatigue in 2014-2022. Patients with prior SED showed associations primarily with stress related diagnoses, including acute stress reaction, reaction to severe stress, as well as post-COVID-19 and post-viral fatigue syndrome. These ORs were all larger for SED than depression. Depression was primarily associated with post-traumatic stress disorder (PTSD), alcohol related and substance use disorders, schizophrenia, schizotypal disorders, delusional disorders, manic episode, bipolar affective disorder, persistent mood disorder, neurotic disorder, borderline personality disorder, autistic disorder, Asperger's syndrome, attention -deficit hyperactivity disorder, attention-deficit disorders ADHD/ADD), and suicide attempt. These ORs were all higher for the depression, although autistic disorders, ADHD/ADD and PTSD were also highly associated with prior SED (OR > 3.5). The divergent psychiatric comorbidity patterns suggest different underlying mechanisms and clinical prognosis.