Concomitant physical symptoms in patients with depression and anxiety associated with poorer prognosis

This study, published in the last 2010 issue of Psychotherapy and Psychosomatics, indicate that concomitant physical symptoms in patients with depression and anxiety are associated with a poorer prognosis of symptoms of depression and anxiety and that it might prove worthwhile to pay attention to the role of multiple physical symptoms in the process of tailoring interventions to meet the needs of depressed and anxious patients in primary care.

A new study, published in the last 2010 issue of Psychotherapy and Psychosomatics by a group of researchers of the University of Amsterdam, has explored the relationship between multiple physical symptoms and the course of depressive and anxiety symptoms in primary care.

Up to 70% of depressed patients present themselves to their general practitioner with physical symptoms instead of psychological symptoms. Given this frequent co-occurrence, it seems plausible that multiple physical symptoms interfere with the course and outcome of symptoms of depression and anxiety. However, it is often difficult to determine whether multiple physical symptoms are an expression of co-morbidity with chronic medical conditions, or whether they are an expression of co-syndromality or somatization. This distinction however might not be relevant if there is no association between multiple physical symptoms and the course and outcome of depression and anxiety.

The Authors of this study hypothesized that multiple physical symptoms might have a generic, but also a differential, effect on the outcome of treatment. This study aims to test both hypotheses in a secondary analysis of data from a recently completed randomized clinical trial (RCT). This RCT assessed the effectiveness of up to 6 sessions of problem-solving treatment compared to 'care as usual' for patients suffering from depressive or anxiety symptoms in primary care. Patients were included in the current analysis if they had filled out the Hospital Anxiety and Depression Scale (HADS; n = 130) at baseline and at follow-up (after 3 months). The course of anxiety and depressive symptoms was defined as unfavorable if the improvement in HADS was ≤ 50% at follow-up. Multiple physical symptoms were measured with the PHQ-15, a scale comprising 15 physical symptoms frequently reported in the outpatient setting (total score: 0-30).

The results of the adjusted logistic regression analysis indicate that the higher the score on the PHQ-15 at baseline, the less likely a patient was to experience a symptom reduction of at least 50% on the HADS. The likelihood of such an unfavorable course was about twice as high for patients scoring 1 SD above average on the PHQ-15. The adjusted odds ratio (OR) was 2.12 per 4.7 points (one SD) on the PHQ-15. The unadjusted OR, with only the PHQ-15 score as an independent variable, was 1.94 per SD (p = 0.012). Adding the interaction term 'randomization status times PHQ-15 score' to the logistic regression model resulted in no significant improvement (p = 0.823). This implies that the outcome was similar in both treatment groups, although this should be interpreted with caution due to the relatively small sample size. This suggests a generic negative influence of multiple physical symptoms on the effectiveness of treatment for symptoms of depression and anxiety in primary care. It is still unclear whether the physical symptoms were due to medical conditions, or whether they were medically unexplained symptoms. These data did not allow to make such a distinction, but this should be the topic of further research.

Either way, the findings of this study suggest that concomitant physical symptoms in patients with depression and anxiety are associated with a poorer prognosis of symptoms of depression and anxiety. In addition, it might prove worthwhile to pay attention to the role of multiple physical symptoms in the process of tailoring interventions to meet the needs of depressed and anxious patients in primary care. A useful tool might be the Diagnostic Criteria for use in Psychosomatic Research (DCPR) that have recently been evaluated in primary care. The DCPR classify 12 psychosomatic syndromes that may play a mediating role in the course and outcome of psychiatric disorders. An assessment according to these can be made by a general practitioner alone or together with a consultant-liaison psychiatrist who can also assist with the choice of treatment.