Somatic and psychiatric co-morbidity in primary care patients in Spain

Background: There is limited information on the subject of co-morbidity of general medical conditions (GMCs) and general psychiatric disturbance in primary care (PC). Methods: A representative sample (n = 1559) of adult PC patients was examined in a two-phase screening. Standardized screening instruments were used, including the Standardized Polyvalent Psychiatric Interview (SPPI). ICD-10 research criteria were used for psychiatric diagnosis, and ICPC-2 for medical diagnosis. Results: Most co-morbidity cases had depressive (120 cases, 28.1%) or anxiety/neurotic disorders (217 cases, 50.9%). In support of the working hypothesis, the proportion of patients with several medical diagnoses was significantly higher among the cases, and logistic regression showed that the probability of being a psychiatric case increased with each medical diagnosis done by the primary care physician (OR = 2.46; IC 1.66-3.66, p < 0.001). Moderate/severe cases were significantly more frequent among the depressed group (91 cases, 75.9%), but were also common in the anxiety/neurosis group (52 cases, 24%), the between groups differences in disability being non-significant. The distribution of both affective and neurotic disorders by specific ICPC-2 categories suggests preferential associations. Conclusion: In PC, the probability of having a co-morbid psychiatric diagnosis doubles with each medical diagnosis. Anxiety/neurotic disorders, and not only depressive disorders, are relevant co-morbid psychiatric categories in this setting.