• anxiety disorders
• comorbidity
• depression
• epidemiology
• functional somatic syndromes
• medically unexplained symptoms
• mood disorders
• primary care
• somatic symptom disorder
• somatization
• somatoform disorders

Aims: In order to contribute to a better understanding of the relationship between somatoform symptoms and mood and anxiety disorders, this study aimed to investigate the prevalence, demographics and severity of somatization, as well as its affective and anxious comorbidities, both in a psychiatric and in a primary care setting.

Methods: A preliminary cross-sectional study was conducted on a total of 81 patients attending three local general practitioners and 91 outpatients of psychiatric services at the University Hospital of Pisa. The Patient Health Questionnaire (PHQ) was used to establish provisional DSM-IV diagnoses of depressive and anxiety disorders in primary care group. Psychiatric patients had their clinical diagnosis of mood and anxiety disorders confirmed by the Mini-International Neuropsychiatric Interview (M.I.N.I.). The Hamilton Depression Rating Scale (HAM-D) and the Hamilton Anxiety Rating Scale (HAM-A) were administered to assess the severity of symptoms of depression and anxiety. Provisional diagnosis of somatoform disorder was made adopting the PHQ diagnostic algorithm, and somatic symptom severity was evaluated with the PHQ-15 score. All statistical analysis was performed using SPSS v.22.0.

Results: The prevalence rate of somatoform disorder was 14.8% (n= 12) in primary care and 24.2% (n= 22) in psychiatric group. Psychiatric patients reported significantly higher somatic symptom severity than those of primary care setting (PHQ-15 mean scores 9.32±4.86 vs. 7.26±4.14, t= 2.97, p= 0.003). Females resulted more likely to express at least moderate somatization (n= 54, 78.3% vs. n= 15, 21.7%, χ2= 8.07, p= 0.005) and showed a more severe somatic symptomatology than males (PHQ-15 mean scores 9.24±4.75 vs. 6.64±3.92, t= 3.6, p< 0.001). In both groups, PHQ-15 and HAM-D scores were strongly correlated (psychiatric: R= 0.74, p< 0.001; primary care: R= 0.70, p< 0.001), as well as PHQ-15 and HAM-A scores (psychiatric: R= 0.79, p< 0.001; primary care: R= 0.75, p< 0.001). In the whole sample, 18 patients with PHQ somatoform disorder (52.9%) met the criteria for a current depressive episode (χ2= 10.36, p= 0.001), while 13 (38.2%) presented a comorbid current anxiety disorder (χ2= 9.92, p= 0.002). Considering psychiatric patients, in our study only 1 subject (4.5%) had a “pure” somatoform syndrome. All other somatoform disorder cases resulted to have a lifetime comorbidity with mood (n= 20, 90.9%) and/or anxiety disorder (n= 11, 50%). In particular, “soft bipolar” patients were more likely to express a comorbid somatoform symptomatology (χ2= 7.33, p= 0.007). Among primary care patients, about 1 out of 3 subjects meeting PHQ criteria for somatoform disorder showed a current depressive episode and/or anxiety disorder (n= 4, 33.3%) (Fisher exact test, p= 0.024).

Conclusions: The prevalence of somatoform disorder in our primary care sample is in line with literature. Psychiatric patients reported higher rates and severity of somatization. Our findings confirm previously reported literature on gender difference in somatization. Data about comorbidity confirm the frequent overlap between somatoform, mood and anxiety syndromes. Patients complaining about somatic symptoms should be assessed with the utmost care. In primary care settings, a psychiatric consultation may be useful in diagnosing and properly treating somatization and its concurrent psychopathology.