Introduction: Psychiatric comorbidity is estimated to occur in up to 40% of all patients with somatic disorders, and it can have an influence on patient morbidity and mortality. Approximately 20% of patients who seek care for abdominal pain receive the diagnosis nonspecific abdominal pain, and later develop chronic abdominal pain. This condition and other abdominal conditions without organic explanation are sometimes called diseases of gut-braininteraction, and psychosocial factors (personality, psychiatric conditions, etc.) have been suggested to play an important role. Organic dyspepsia (which in this thesis is limited to pepticulcer, gastritis and gastro-esophageal reflux disease, or GERD) has previously been reported to be associated with personality traits and psychiatric conditions. Despite these known associations, few studies have specifically investigated psychiatric comorbidity in patients with acute abdominal conditions.The aim of this thesis is to investigate the prevalence of psychiatric comorbidity in patients with acute abdominal pain conditions in the emergency setting and to evaluate the possible longterm psychiatric problems of these patients.

Methods: Consecutive patients with who came to emergency care with acute abdominal pain conditions were divided into three diagnostic groups: acid-dependent organic dyspepsia (pepticulcer, gastritis and GERD), specific abdominal diagnoses, and non-specific abdominal pain.These groups were evaluated for personality traits, psychiatric symptoms, and self-rated health.A follow-up study explored prescription of antidepressant and anxiolytic (anti-anxiety) medications in this patients 10–15 years after the initial visit to emergency care.

Results: Among the various diagnostic groups, patients with acid-dependent organic dyspepsia had significantly more anxiety-related personality traits, less mature characters, significantly more psychiatric symptoms, and poorer self-rated health. Patients with nonspecific abdominal pain also had more personality traits associated with anxiety, although to a lesser extent. Personality factors were significantly associated with poor self-rated health. The long-term follow-up showed that patients with organic dyspepsia and non-specific abdominal pain were prescribed antidepressants and anxiolytic drugs statistically more often than patients with specific abdominal diagnoses.

Conclusion: Patients with abdominal pain who seek emergency care have enhanced psychiatric comorbidity, more anxiety-related personality traits, and poorer perceived health.This trend is particularly evident in patients with a diagnosis of acid-dependent organicdyspepsia, and to a lesser degree, patients with a diagnosis of non-specific abdominal pain.These factors also predict future prescription of depression and anxiety medications. These results suggest that patients who come to emergency care with acute abdominal pain could potentially benefit from psychiatric consultation.