A study conducted as part of the development of the Eleventh International Classification of Mental Disorders for Primary Health Care (ICD-11 PHC) provided an opportunity to test the relationships among depressive, anxious and somatic symptoms in PHC.

Primary care physicians participating in the ICD-11 PHC field studies in five countries selected patients who presented with somatic symptoms not explained by known physical pathology by applying a 29-item screening on somatic complaints that were under study for bodily stress disorder. Patients were interviewed using the Clinical Interview Schedule-Revised and assessed using two five-item scales that measure depressive and anxious symptoms. Structural models of anxious-depressive symptoms and somatic complaints were tested using a bi-factor approach.

A total of 797 patients completed the study procedures. Two bi-factor models fit the data well: Model 1 had all symptoms loaded on a general factor, along with one of three specific depression, anxiety and somatic factors [x2 (627) = 741.016, p < 0.0011, RMSEA = 0.015, CFI = 0.911, TLI = 0.9]. Model 2 had a general factor and two specific anxious depression and somatic factors [x2 (627) = 663.065, p = 0.1543, RMSEA = 0.008, CFI = 0.954, TLI = 0.948].

These data along with those of previous studies suggest that depressive, anxious and somatic symptoms are largely different presentations of a common latent phenomenon. This study provides support for the ICD-11 PHC conceptualization of mood disturbance, especially anxious depression, as central among patients who present multiple somatic symptoms.

The main objectives of the survey were: (a) to analyse the sociological, clinical and illness-related correlates of mental illness in primary care; (b) to study, during one-year follow-up, outcome and use of health resources.

The survey comprised a two-phase cross-sectional study. In the first phase patients were classified using the GHQ-28 or by the general practitioner (GP). In the second phase they were assessed by the SCAN system.

The prevalence rate of mental illness (in attenders) using the GHQ was 33.2%. The corresponding rate for the GP was 14.1%, and for the SCAN 31.5%. Mental illness mainly comprised depression, anxiety and alcohol-related diagnoses. The presence of mental illness and the use of health resources during follow-up were dependent on demographic characteristics and on their original psychiatric status.

In primary care, mental illness constitutes a major health problem. Despite this fact. GPs do not recognise a substantial proportion of these health problems.