Symptoms in the community. Prevalence, classification, and psychiatric comorbidity

While physical symptoms are the leading reason for outpatient visits, a substantial proportion of physical complaints and "minor" illnesses remain poorly understood. The purpose of our study was to determine the prevalence, patient-attributed cause, and psychiatric comorbidity of symptoms in a general population.

We analyzed data on 13,538 individuals interviewed in the Epidemiologic Catchment Area Program, a multicommunity mental health survey that used the Diagnostic Interview Schedule to determine the prevalence of psychiatric disorders. The Diagnostic Interview Schedule inquires about 38 physical symptoms and includes a probing scheme to classify symptom severity and potential cause. We focused on 26 symptoms most germane to primary care.

Of the 26 symptoms, 24 had been problems for more than 10% of persons at some point in their life, with the most common nonmenstrual symptoms being joint pains (36.7%), back pain (31.5%), headaches (24.9%), chest pain (24.6%), arm or leg pain (24.3%), abdominal pain (23.6%), fatigue (23.6%), and dizziness (23.2%). Most symptoms (84%) were at some point considered major in that they interfered with routine activities or had led individuals to take medications or visit a physician. Nearly one third of symptoms were either psychiatric or unexplained, and most symptoms were associated with at least a twofold increased lifetime risk of a common psychiatric disorder.

Symptoms in the community are prevalent as well as bothersome. Often lacking an apparent physical explanation, such symptoms are associated with an increased likelihood of psychiatric disorders.