Depression

Gill van der Watt, Jonathan Laugharne, Aleksandar Janca
School of Psychiatry and Clinical Neurosciences, University of Western Australia, Perth, Australia

01/15/2008

Abstract and Introduction

Abstract

Purpose of Review: There is well documented evidence for the increasing widespread use of complementary and alternative medicine in the treatment of physical and psychiatric symptoms and disorders within Western populations. Here we provide a review of the recent literature on evidence for using such interventions in the treatment of anxiety and depression.
Recent Findings: With regard to herbal treatments, kava is effective in reducing anxiety symptoms and St John's wort in treating mild to moderate depression. The association of kava with hepatotoxicity, however, is a significant concern. Promising data continue to emerge for the use of omega-3 fatty acids in managing depression. Evidence for the use of acupuncture in treating anxiety disorders is becoming stronger, although there is currently minimal empirical evidence for the use of aromatherapy or mindfulness-based meditation.
Summary: The evidence base for the efficacy of the majority of complementary and alternative interventions used to treat anxiety and depression remains poor. Recent systematic reviews all point to a significant lack of methodologically rigorous studies within the field. This lack of evidence does not diminish the popularity of such interventions within the general Western population.

Introduction

Interest in complementary and alternative medicine (CAM) continues to grow as an increasing number of people, including health care professionals, look at ways to improve their own lives and those of others by using a variety of alternatives to conventional medicine. There are difficulties in reviewing research in CAM because of the diversity of practices included under the term and the various ways in which it is applied across different cultures. The World Health Organization refers to the increase in the use of nonconventional medicine, meaning traditional, complementary and alternative medicine, in countries all over the world in its Traditional Medicine Strategy 2002-2005.^[1] Some authors group complementary medicines into herbal remedies (food supplements that include vitamin preparations and other organic and inorganic substances, such as omega-3 fatty acids),^[2*] whereas others list individual therapies such as acupuncture, aromatherapy, herbal therapy, homeopathy, iridology, naturopathy and reflexology under the umbrella of CAM.^{[3-6,7*,8*,9]} There is ongoing debate regarding the level of evidence required by the scientific community and appropriate methodological approaches in CAM research, including the feasibility and complexities of using randomized controlled trials (RCTs) and difficulties in identifying suitable placebos.^[10]

Kessler et al.^[11] reported data on the use of complementary therapies to treat anxiety and depression in the USA, which indicate that complementary and alternative therapies are used more than conventional therapies by people with anxiety and severe depression. This large-scale study found depression, anxiety and insomnia to be among the most common reasons for people to use complementary therapies. For example, 53.6% of respondents suffering from severe depression reported using complementary and alternative medicine for treatment during the 12 months before the survey.

In the UK, estimates of the proportion of the general population using CAM range from 14% to 30%^[12] and consumer surveys in other European countries indicate positive public attitudes toward the use of complementary therapies, with acupuncture being identified as one of the most popular forms of complementary treatment.^[13] The findings of a large postal survey conducted in Australia^[3] showed that people who were experiencing mild to moderate depression chose self-help strategies and complementary therapies such as aromatherapy, St John's wort, meditation and nutritional supplements rather than seeking professional help. In contrast, those with severe depression were more likely to seek conventional professional help and did not tend to use complementary therapies.

Here we review recent research in CAM approaches to the treatment of anxiety and depression, including use of herbal interventions, nutritional and dietary supplements, acupuncture, light therapy, meditation and hypnosis.

Depression

Complementary and alternative treatments for depression and depressive disorders discussed in this report are grouped into the following categories: herbal interventions, nutritional supplements and aromatherapy; cognitive interventions, including hypnotherapy, CBT and mindfulness-based cognitive therapy; and physical interventions, including acupuncture and light therapy.

Herbal Interventions, Nutritional Supplements and Aromatherapy

A recent review reported by Ernst^[15*] indicated that St John's wort (Hypericum perforatum) is the only herbal remedy found to be effective as a treatment for mild to moderate depression. The author discussed a previous meta-analysis published in German language by Roder et al..^[27] In five trials involving 2231 patients that compared St John's wort with conventional antidepressants, Roder et al. found both approaches to be equally effective. St John's wort was significantly effective when compared with placebo in 25 trials involving a total of 2129 patients. Ernst cautioned against using St John's wort with other medications because it can increase the plasma levels of a range of drugs and there is a possibility that it can occasionally trigger psychosis in patients who are using selective serotonin reuptake inhibitors.

Thachil et al.^[9] conducted a review of the evidence for complementary therapies used in depression by searching the literature for studies on CAM as monotherapy. Nineteen reports were reviewed, yielding grade 1 evidence (strong evidence from at least one systematic review of multiple well designed RCTs) for the use St John's wort, tryptophan/5-hydroxytryptophan, S-adenosyl methionine, inositol and folate in depressive disorders. None of these findings was conclusively positive, and folate had a significant effect only when combined with an antidepressant. The review found grade 2 evidence (strong evidence from at least one properly designed RCT of appropriate size) for the use of saffron in mild to moderate depression, but the results are inconclusive and large-scale trials are warranted to investigate further its potential as an effective treatment.

Mischoulon^[28**] reported that the results of recent studies of omega-3 fatty acid supplementation, including the use of eicosapentaenoic acid (EPA), are promising in treatment of depression. In addition, the omega-3 fatty acids have been shown to be safe and might be useful in specific populations, such as the elderly, pregnant or lactating women, and people with medical co-morbid conditions. A number of controlled trials and a few open studies have suggested that supplementation with doses of EPA and docosahexaenoic acid (DHA) that are about five times higher than the standard dietary intake in the USA may have antidepressant or mood-stabilizing effects. Mischoulon described as compelling the evidence for the efficacy and safety of omega-3 fatty acids to treat patients with depression, but recommended that more well designed controlled trials be conducted in larger patient populations. He suggested that, although the data remain inconclusive, patients with mild depression or those who are unresponsive to conventional antidepressants might be the best candidates for alternative treatments such as St John's wort and omega-3 fatty acids.

Clayton et al.^[29] reviewed the evidence for the rationale and benefit of omega-3 fatty acids in the treatment of psychiatric disorders in children and adolescents, and found some evidence of likely benefit in the treatment of unipolar depression. The authors emphasized the importance of conducting further well designed research, taking into account the importance of blinding patients and researchers to treatment and choosing appropriate placebos and omega-3 fatty acids (EPA and DHA.)

Aromatherapy research was recently reviewed by Perry and Perry.^[18*] They discussed the antidepressant properties of essential oils such as bergamot (Citrus bergamia) and geranium (Pelargonium graveolens) in a report offering clinical and neuropharmacological perspectives of aromatherapy in managing psychiatric disorders. Although some studies have shown an association between aromatherapy and improvement in mood in healthy adults, there is a notable lack of methodologically sound trials in clinically depressed populations. No conclusions can be drawn regarding the efficacy of aromatherapy in treating depression until such trials are conducted. The authors arrived at the overall conclusion that, based on relevant neuropharmacological and limited clinical evidence, aromatherapy is a treatment with major but relatively unexplored potential in the field of clinical psychiatry.

Cognitive Interventions

Alladin and Alibhai^[30] compared the effectiveness of the combination of hypnosis and CBT, which they termed cognitive hypnotherapy, with that of standard CBT in 84 patients with major depression. Patients were randomly assigned to the two treatment groups, which were run over 16 weeks. The investigators found that treatment outcomes were significantly enhanced when CBT was combined with hypnotherapy. Patients from both groups exhibited significant improvements compared with baseline scores, with greater reductions in depression, anxiety and hopelessness in the cognitive hypnotherapy group than in the CBT group. This improvement was maintained at 6 and 12 months of follow up. The authors suggested that further expanded studies across multiple settings are required to replicate these findings. In addition, they propose the use of a dismantling design to clarify which subcomponents of the hypnotherapy intervention are most important.

In their wide-ranging review of complementary treatments for depression, Pilkington et al.^[8*] concluded that two recent trials suggest that mindfulness-based cognitive therapy, which integrates aspects of CBT with components of MBSR programmes, may be useful in preventing relapse in people who have recovered from depression. In more general terms, the authors found that, although use of complementary medicine for the management of depression is widespread, there is currently a rather limited evidence base for the efficacy of CAM treatments compared with that for antidepressants or CBT, and that the findings reported remain inconclusive because of small sample sizes, inadequate follow up, limited information on attrition and lack of blinding.

Physical Interventions

The first systematic review of RCTs investigating the efficacy of acupuncture in treating depression was that conducted by Leo and Ligot.^[31] They examined nine RCTs, five of which were considered to be of poor methodological quality, and found that acupuncture tended to be as effective as antidepressants in treating depression in the limited studies available for comparison. The authors stated, however, that the overall evidence remains inconclusive because of the varied methodology and study designs used, but that further research investigating the use of acupuncture in treating depression is warranted.

MacPherson and Schroer^[32*] attempted to resolve the problem of variability in application of acupuncture treatment, which makes it difficult to test the effectiveness of this intervention empirically. They described acupuncture as a complex intervention because of the difficulty in precisely defining what the active ingredients are and how they relate to each other. The authors reported the process of implementing a consensus method to develop a standardized treatment protocol in preparation for a RCT of acupuncture to treat depression. Components likely to be essential to the intervention that would need to be incorporated into the protocol were identified and rated over two rounds of evaluation by 15 practitioners. Such standardization is an important step towards improving the methodological rigour of clinical trials conducted using CAM interventions.

Light therapy is another physical intervention that is used to treat depression and depressive disorders. It exposes patients to a bank of bright lights for a variable number of hours per day, usually between 1 and 3 h. Patients can read or engage in other activities during the period of exposure. In a recent paper that reviewed CAM therapies in the treatment of depression in children and adolescents, Jorm et al.^[7*] found good evidence for the efficacy of light therapy in winter depression. There was no evidence that it would be effective for nonseasonal depression because of the very limited data available, suggesting that further research is warranted.