Balneotherapy versus paroxetine in the treatment of generalized anxiety disorder

Summary

Introduction

Preliminary studies have suggested that balneotherapy (BT) is an effective and well-tolerated treatment for generalized anxiety disorder (GAD) and psychotropic medication withdrawal syndrome. We carried out a study in 4 spa resorts to assess the efficacy of BT in GAD.

Method

We compared BT to paroxetine in terms of efficacy and safety in a randomized multicentre study lasting 8 weeks. Patients meeting the diagnostic criteria of GAD (DSM-IV) were recruited. Assessments were conducted using the Hamilton Rating Scale for Anxiety (HAM-A) and other scales, by a specifically trained and independent physician. The primary outcome measure was the change in the total HAM-A score between baseline and week 8.

Results

A total of 237 outpatients were enrolled in four centres; 117 were assigned randomly to BT and 120 to paroxetine. The mean change in HAM-A scores showed an improvement in both groups with a significant advantage of BT compared to paroxetine (−12.0 vs −8.7; p < 0.001). Remission and sustained response rates were also significantly higher in the BT group (respectively 19% vs 7% and 51% vs 28%).

Conclusion

BT is an interesting way of treating GAD. Due to its safety profile it could also be tested in resistant forms of generalized anxiety and in patients who do not tolerate or are reluctant to use pharmacotherapies.

Introduction

Generalized anxiety disorder (GAD) characterized by extensive and “uncontrollable” worrying and anxiety, and lasting for at least 6 months, is a common and disabling disease (APA, 1994). According to the National Comorbidity Survey in the United States,¹ lifetime prevalence of GAD is 5.1% and 1-year prevalence is 3.1%. The course of GAD is chronic and its mean duration is 20 years.² Lieb et al. also report high prevalence rates in Europe.³ GAD has severe consequences for the affected patients, and poses a significant cost to society.⁴

In France GAD prevalence is 29% in outpatients attending psychiatric clinics,⁵ and 8% in patients seen in general practice.⁶

Comorbidity with other psychiatric disorders is frequent, especially with major depression (>40–62%) and/or dysthymia (40%)⁷ introducing the risk of misdiagnosis and the possibility of concomitant medication issues that lead to a high frequency of relapse.⁸

Among pharmacotherapies proposed for GAD, antidepressants and particularly selective serotonin reuptake inhibitors (SSRI) and serotonin-norepinephrin reuptake inhibitors (SNRIs) are considered first-line therapies. Paroxetine, escitalopram and venlafaxine are approved for the treatment of GAD as well as depression by the U.S. Food and Drug administration (FDA).⁹ SSRIs and SNRIs are also approved for the same indications by the European regulatory authorities. Paroxetine has been shown to be effective in a randomized double blind, placebo controlled study with remission rate in responders up to 73% and only 11% relapsing in the 32 weeks.¹⁰

Among psychotherapies, cognitive-behavioural therapy (CBT) is the most extensively studied in the treatment of GAD. Meta-analyses suggest the superiority of CBT in reducing anxiety symptoms compared to the absence of treatment or other psychotherapeutic approaches. Moreover these studies indicate that CBT effects may remain stable during a 12-month follow-up period.¹¹

However, resistance to drugs or CBT requires other approaches. Traditionally, spa therapy, providing balneotherapy (BT) with mineral water and other types of somatic care in the environment of a spa resort, has been used for the treatment of affective disorders, anxiety disorders and withdrawal syndromes. A consensus exists among professionals that BT can be considered as an effective treatment for several types of somatic and psychiatric disorders, although this is currently based only on observational studies.12, 13 No study has ever compared BT to psychotherapies and psychotropic medications in terms of efficacy.

However, a decrease of salivary cortisol levels, a stress marker also modified by psychotropic drugs, was reported after spa bathing¹⁴ and the affinity of the serotonin transporter, altered in depression, appears increased 30 min and 1 week after balneotherapy in ozonized water.¹⁵ Warm footbaths have been shown to induce relaxation with a concomitant decrease of sympathetic tone and serum cortisol levels as well as an elevation of salivary secretory Ig A titers.¹⁶ A local effect through nociceptive skin receptors and central effects on endomorphins and immune factors have also been advocated.¹⁷ BT has been proposed to patients suffering from anxiety disorders.¹⁸ This procedure has shown its usefulness not only in somatic but also psychic symptoms of anxiety. Nevertheless most patients receive a concomitant psychotropic medication. This led us to consider whether BT alone might be effective in the treatment of GAD.