Summary of main results
Six trials were included in this review incorporating 402 women from the United States, Switzerland, and Taiwan. The body of evidence provided in this review does not allow for a strong conclusion regarding non-pharmacological/psychosocial/psychological interventions for the treatment of antenatal depression. Only six trials were included and all treatment approaches had two or less trials providing evidence for effectiveness (acupuncture = two trials; massage = one trial; bright light therapy = one trial; omega-3 fatty acids = two trials). Outcome measures for each individual treatment approach varied resulting in no data being combined for the primary outcome. The methodological quality for most of the included trials was not strong with many common limitations such as unclear randomisation procedures, small and homogeneous samples, unclear blinding of outcome assessors, and high attrition rates. These limitations render any results questionable.
One three-armed trial tested the efficacy of maternal massage and depression-specific acupuncture for the treatment of depressed pregnant women (Manber 2004). This pilot study of 61 US women found that neither the 12 20-minute massage sessions nor the 12 25- to 30-minute depression specific-acupuncture sessions were more effective in reducing depressive symptoms than non-specific acupuncture. In a larger trial by the same group (Manber 2010), maternal massage sessions again were not more effective in achieving a significant treatment response or obtaining depression remission than non-specific acupuncture. However, this trial did find that depression-specific acupuncture was more likely to produce a treatment response than non-specific acupuncture; no effect was found related to depression remission. One trial evaluated the effect of maternal massage by a women's significant other versus standard care (Field 2009a). Women who received the massage where significantly more likely to experience a decrease in depressive symptomatology than those who received standard care; there was no impact on maternal anxiety. In a trial by Wirz-Justice 2011, bright light therapy was not more effective than inactive bright light therapy in providing a treatment response or promoting depression remission. However, there was a significantly greater change in mean depression scores in those who received the active bright light therapy than those who received inactive therapy. While two trials evaluated omega-3 fatty acids for the treatment of antenatal depression, neither trial evaluated a similar outcome so their results could not be combined. In the trial by Su 2008, women who received omega-3 fatty acids were not more likely to achieve depression remission or have a treatment response. However, in this trial women who received omega-3 fatty acids had significantly lower mean depressive symptoms scores following treatment than those receiving a placebo. In the trial by Freeman 2008, there was no significant difference in the change in mean depression scores for women receiving omega-3 fatty acids and those receiving a placebo. In both trials, very few women reported a side effect and there was no differences in reporting an event between those who received omega-3 fatty acids and those who received a placebo.
Overall completeness and applicability of evidence
The treatment of antenatal depression using non-psychosocial/psychological interventions is an area that has been neglected, despite antenatal depression being a significant public health concern. This updated review added five new trials to the original review which only included one study (Manber 2004). The original trial in this review tested the efficacy of massage and depression-specific acupuncture for the treatment of depressed pregnant women. Another larger, acupuncture trial (n = 149) has been added by the same research group (Manber 2010). This trial found acupuncture specific for depression was associated with a significantly higher rate of response compared to control acupuncture (acupuncture not specific for depression). Several sample characteristics limit the generalisability of the results including the high education and socioeconomic status, predominance of Caucasians, and exclusion of comorbid mental and medical disorders. As such, the results are not generalisable to specific minority groups or pregnant women with other mental health concerns. While this trial alone does not provide strong evidence to indicate acupuncture should be used for the treatment of antenatal depression, the results are consistent with two other recent reviews that found acupuncture, including manual-, electrical-, and laser-based, is a generally beneficial, well-tolerated, and safe treatment for depression (Wang 2008; Wu 2012). The studies included in these reviews had many methodological limitations such as small sample size and unclear description of enrolment criteria, randomisation or blinding, and forms of acupuncture used. Recently, a randomised, subject- and assessor-blind, parallel-group, sham-controlled trial was conducted to evaluate the effect of acupuncture on postpartum depression among 20 Hong Kong mothers (Chung 2012). Although this trial was generally well designed, no significant differences were found between the two groups. This negative finding may possibly be the result of a type II error as the study may have had insufficient power to detect differences between the study groups due to the small sample size. Despite consistent methodological limitations, there is growing evidence to suggest that acupuncture may be beneficial for the treatment of depression and large, well-designed randomised controlled trials are warranted to evaluate the effectiveness of acupuncture with depressed pregnant women.
Very few studies have been conducted to evaluate the effect of massage on the treatment of antenatal depression. The one trial included in this review that evaluated maternal massage compared with standard treatment care (Field 2009a) found women who received the massage intervention were significantly more like to experience a decreased depressive symptomatology. However, in this trial the massage intervention was provided by the woman's significant other. Given that a lack of support and a poor intimate partner relationship are significant risk factors for antenatal depression (Lancaster 2010), the beneficial effect found in the trial may have been due to the additional attention provided by the women's significant other rather than the intervention itself. The other trial in this review that examined massage by a therapist versus non-specific acupuncture (control group) found no beneficial effect of massage (Manber 2004). In a recent systematic review of 17 randomised controlled trials of moderate quality, massage therapy was found to be effective in alleviating depressive symptoms (Hou 2010). Additional research in this area is warranted; however, standardisation of massage therapy protocols are required to provide comparable results.
In this review, only one trial was included that evaluated the effect of bright light therapy (Wirz-Justice 2011). While no beneficial effect on treatment response or depression remission was found, there was a significantly greater change in mean depression scores from baseline in those who received the active bright light therapy than those who received inactive therapy. This result is consistent with a systematic review of light therapy for non-seasonal depression that reported the efficacy of bright light against placebo conditions (Even 2008). This review noted that most of the studies included had small numbers, inadequate control conditions, and were short-term (two to five weeks). The side effects of bright light therapy include headache, eye strain, nausea, and agitation, but these are generally mild and rarely lead to treatment discontinuation (Ravindran 2009). Bright light therapy may be an attractive treatment for antenatal depression because it is low cost, home-based, and has a much lower side effect profile than pharmacotherapy. In a interesting review by Crowley 2012, there are several factors related to the pathophysiology of depression and response to light which might make bright light especially suitable for antenatal depression. For example, bright light treatment could potentially offset insufficient low levels of light exposure; pathological hormonal profiles; co-morbidities, including disturbed sleep and fatigue; and serotonergic dysregulation which has been linked to inadequate maternal behaviour. Only three studies (Epperson 2004; Oren 2002; Wirz-Justice 2011) have examined bright light therapy in depressed pregnant women. Larger randomised controlled trials are needed since bright light may be preferable to other types of treatment.These trials should have adequate control conditions, provide treatment for five weeks or longer, provide comparative effectiveness, and address co-morbidities that bright light could alleviate such as anxiety, disturbed sleep, and fatigue.
While omega-3 fatty acids are one of the most widely used non-vitamin supplements, there are insufficient data from adequately powered controlled trials to say whether omega-3 fatty acids are efficacious in the treatment of depression (Freeman 2011). Most randomised controlled trials have been small and of short duration and have yielded inconsistent findings (Freeman 2011). Further, the majority of trials have evaluated omega-3 fatty acids as an adjunctive treatment and the doses and composition of the omega-3 supplements have been extremely variable. In this review, two trials (Freeman 2008; Su 2008) evaluated the effect of omega-3 fatty acids as a treatment for antenatal depression. One trial (Su 2008) found a positive effect of omega-3 fatty acids on depressive symptomatology immediately post-treatment while the trial (Freeman 2008) did not. However, there was significant improvement from baseline in both groups in this trial, which could be attributed to the supportive therapy that all women in both groups received. It is important to note that this trial was very small (n = 21) and insufficiently powered to detect differences between study groups. Given the growing evidence that supports the role that omega-3 fatty acids plays in mental illness and health (Freeman 2011), research examining the effect of omega-3 supplementation in the treatment of antenatal depression is warranted. Future trials should determine if: (1) omega-3 fatty acids are efficacious as a monotherapy; (2) there is an optimal dose, ratio of EPA/DHA, and treatment course; and (3) the dose needs to be tailored to individuals based on dietary habits (Freeman 2011).
There were no trials evaluating other non-psychosocial/psychological interventions in the treatment of antenatal depression such as physical exercise. Exercise is a relatively low-cost intervention, with minimal side effects, and there is now evidence to support the antidepressant effects of exercise in general and clinical populations (Lawlor 2001). Limited evidence also supports a relationship between participation in exercise and a reduction in postpartum depression. For example, a review article explored the potential role of exercise, particularly pram walking, as an adjunctive treatment for postpartum depression (Daley 2007). Two small randomised controlled trials conducted in Australia were included in this review, which supported exercise as a useful treatment for women with postpartum depression (Armstrong 2003; Armstrong 2004). Given the reluctance by some women to use anti-depressant medication antenatally and the limited availability of psychosocial and psychological therapies (Dennis 2007b), exercise as a therapeutic possibility for depressed pregnant women deserves further exploration.