Self-esteem has been defined as a person's overall evaluation of his or her own worth (Hewitt, 2009). Low self-esteem is involved in a wide range of psychiatric conditions, including depression (Brown et al., 1990), anxiety disorders (Sowislo and Orth, 2013), personality disorders (Lynum et al., 2008) obsessive compulsive disorder (Ehntholt et al., 1999), eating disorders (Gual et al., 2002), chronic pain (Soares and Grossi, 2000), substance abuse (Silverstone and Salsali, 2003), and psychosis (Barrowclough et al., 2003). Research suggests that low self-esteem increases the susceptibility for development of these psychiatric disorders, and that, in turn, the presence of a psychiatric condition negatively influences someone's self-esteem (Silverstone and Salsali, 2003). There is also considerable evidence to support the notion that in general self-esteem is a reliable predictor of treatment outcome, in that higher initial self-esteem is significantly associated with better treatment outcomes (Johnson et al., 2000; Parker et al., 2013). It can be concluded that low self-esteem is an important factor in relation to psychiatric disorders in general.

Over the past several years a variety of therapeutic interventions has been developed for changing low self-esteem, predominantly with a cognitive behavioral background. These interventions mostly aim at changing core beliefs underlying patients' low self-esteem (Padesky, 1994; Beck, 1995; Fennell, 1999). Several case studies (Fennell, 1998; McManus et al., 2009) and clinical trials (Rigby and Waite, 2006; Waite et al., 2012) suggest that these interventions are effective in enhancing self-esteem. However, only a few studies have compared Cognitive Behavioural Therapy (CBT) to an active or passive control group using a randomized controlled trial. One study examined the effectiveness of CBT on improving implicit and explicit self-esteem in patients with a social anxiety disorder, comparing this to psychodynamic therapy using 25 sessions (Ritter et al., 2013), and found a positive treatment effect for both treatments. Another study found a positive effect of CBT being significantly more effective in changing self-esteem in comparison to a waitlist control condition (Waite et al., 2012). Some studies have also addressed the effectiveness of group CBT on individuals' self-esteem, mostly using protocols designed by Fennell (1998), showing significantly positive treatment effects, including a reduction of symptoms of depression and anxiety (Rigby and Waite, 2006; Morton et al., 2012; Pack and Condren, 2014). Hence, research thus far found support for the effectiveness of CBT for individuals suffering from low self-esteem.

It is an observation in clinical practice that when treating low self-esteem in patients with psychiatric comorbidities or more severe symptoms of psychiatric conditions, the application of cognitive interventions may not always be sufficient to effectively change patient's core beliefs. Patients frequently report that they still “feel” bad about themselves, albeit rationally believing that their core beliefs are not true (Young et al., 2002; Sanders and Ten Broeke, 2011). This suggests that a treatment that would intervene in a different manner, perhaps on a more affective level, and make patients actually “feel” more worthy, could be more effective, or at least be an additional tool for enhancing self-esteem.

Eye Movement Desensitization and Reprocessing (EMDR) therapy is considered to be a treatment method that intervenes on a more affective level (Shapiro, 2001). EMDR therapy is a protocolized psychotherapeutic treatment that is used to treat symptoms caused by distressing and unprocessed life events through reducing the vividness and disturbance of the memories of such events (Shapiro, 2007; Solomon and Shapiro, 2008). Although EMDR is mainly used for treating posttraumatic stress disorder (PTSD), it has been argued that EMDR therapy might also be an effective therapy for changing low self-esteem (De Jongh et al., 2010). Assuming that core beliefs underlying the low self-esteem developed as a consequence of subsequent learning experiences, EMDR may be used to reprocess emotionally charged memories that the patient considers to be “evidence” for his or her core belief (De Jongh et al., 2010). According to this case conceptualization, processing these memories using EMDR would make it possible to re-evaluate the present meaning of those experiences, thereby positively influencing their self-esteem.

Several case studies have shown a positive effect of EMDR on low self-esteem (Dziegielewski and Wolfe, 2000; Shapiro, 2001; Maxwell, 2003; Sanders and Ten Broeke, 2011). The results of a randomized controlled trial among 26 adolescents with self-esteem and behavioral problems showed that EMDR was effective in enhancing their self-esteem (Wanders et al., 2008). The researchers used four sessions EMDR therapy and compared this to four sessions of CBT, which contained strategies to teach children practical skills, to identify negative feelings and unhelpful thoughts, to replace these with more positive thoughts and to face and overcome their problems and challenges. Although both therapies where found to be effective, EMDR resulted in significantly more behavioral changes than CBT. Recently, Staring et al. (2016) used a randomized controlled trial with a crossover design among 47 adults with anxiety disorders to compare six sessions EMDR therapy with an equal number of sessions Competitive Memory Training (COMET) that aims to activate positive representations for enhancing self-esteem. They found that EMDR improved self-esteem, but they found a significantly stronger effect of COMET compared to EMDR therapy. Thus, the few studies that investigated the effectiveness of EMDR applied on self-esteem have so far shown mixed results. There are some explanations for these contradicting findings. First, until now, only a few sessions (4–6) of EMDR therapy have been used. It is conceivable that for changing individuals' long existing negative core beliefs, a wide array of memories would have to be targeted, “proving” that the person is bad or worthless. Furthermore, it could be argued that in the study of Staring et al. (2016) the memories that were targeted with EMDR, and that were deemed to contribute to patients' low self-esteem, could have been relatively low in emotional charge and, consequently, less sensitive to EMDR (Littel et al., 2017). Therefore, it could be hypothesized that especially patients with severe pathology and multiple diagnoses, associated with lower self-esteem (Silverstone and Salsali, 2003), might have memories underlying their low self-esteem with higher emotional charge, making them more likely to benefit from EMDR therapy.

The purpose of the current study was to test the effectiveness of EMDR therapy in adults with low self-esteem in a secondary mental health care population, by comparing it to a cognitive behavioral approach, using a randomized controlled trial. We hypothesized a significant improvement in self-esteem after 10 weekly sessions of treatment. It was hypothesized that the results associated with both interventions would be maintained at 3 months follow-up. The second aim of the study was to examine the difference in effectiveness between both treatments.

The results of the present study suggest that both EMDR therapy and CBT have the potential to be an effective treatment alternative for patients who suffer from low self-esteem in co-occurrence with a wide range of psychiatric disorders.

Patients improved not only more than two standard deviations on the primary outcome measure (Rosenberg Self-esteem Scale), the treatments also led to significant reductions in general psychiatric symptoms and social anxiety, as well as to a significant increase of social interactions. All treatment effects were maintained at 3 months follow up. These results were held after an intention-to-treat analysis was performed that included all patients who dropped out early in treatment. For the majority of the patients (60%), the amount of 10 therapy sessions resulted in a clinically significant improvement in self-esteem. No significant differences could be detected between the two therapies.

The results of this study are in line with the study of Wanders et al. (2008) who found similar effects in adolescents, in that EMDR therapy and CBT proved equally effective in changing low self-esteem. Conversely, the results are at odds with those of Staring et al. (2016) who found EMDR to be less effective in treating low self-esteem than COMET. Patients in the current study showed a larger improvement on self-esteem compared to Staring et al. (2016). This difference in results may be explained by the amount of sessions provided, in that Staring et al. (2016) used six sessions whereas the patients in the current study received ten sessions. Also it is likely that the memories targeted with EMDR in the current study with patients with multiple psychiatric diagnoses, were more emotionally charged and hence more susceptible for processing using EMDR therapy (Littel et al., 2017). Concerning CBT, in contrast to Ritter et al. (2013), who used 25 sessions of CBT to treat low self-esteem, we found that 10 sessions of CBT were sufficient to establish changes in self–esteem in the majority of the patients. The effectiveness of CBT in changing low self-esteem found in the present study (effect size on the RSES ηp 2= 0.49), is in line with former studies on group CBT (Rigby and Waite, 2006; Morton et al., 2012; Pack and Condren, 2014).

This study had several strengths. Firstly, it is one of the first RCTs explicitly focussed on the effectiveness of EMDR therapy for low self-esteem in adults, and also one of the first RCTs examining the efficacy of CBT in treating low self-esteem. In contrast to former studies examining the effect of EMDR on low self-esteem (Wanders et al., 2008; Staring et al., 2016), the current study explicitly excluded patients with PTSD, making it more likely that the EMDR therapy was in fact effective in changing self-esteem instead of treating trauma related symptomatology. Secondly, regarding self-esteem treatment, the present study was one of the first to include a diverse patient group with various psychiatric disorders. The results suggest that EMDR as well as CBT are effective for treating low self-esteem in such a difficult population. Finally, this study used a follow-up measure to examine the treatment outcomes over time, showing that the treatment effects of both EMDR and CBT were maintained.

While the present study results are encouraging, there are a number of limitations that need to be acknowledged. First, given the relatively small sample size, it cannot be ruled out that the fact that no differences between groups were found were due to the fact that this study was underpowered. Secondly, because the EMDR treatment was delivered individually whereas the CBT treatment was given in a group setting, it could be argued that the experience of being accepted within a group and meeting other people who share similar difficulties, would be therapeutic for individuals with low self-esteem. Conversely, patients in the EMDR condition could have profited more from the individual attention of the therapist, feeling perhaps more comfortable in this context to display their deepest feelings and beliefs. Thirdly, there was a significant difference in age between patients in the EMDR and CBT condition. However, age differences in self-esteem generally appears to be relatively small compared to interindividual differences, like personality traits, and measurement error (Pullman et al., 2009; Orth et al., 2010). This is in line with the pre-treatment measurements as found in the current study in that despite the difference in age between both groups differences on self-esteem measures were lacking. Finally, this study lacked a passive control group, so it cannot be ruled out, however unlikely, that patients improved simply because of getting attention from the therapist and not because of the specific treatments methods.

Looking at an individual level, not all patients benefited equally from treatment. This was the case for the CBT as well as for the EMDR condition. Given that both treatments were effective at group level, specific patient groups might have benefited more or less from different kinds of interventions. Likewise, while for the majority of the patients ten sessions were enough to reach a clinical significant improvement in self-esteem, for the non-responders perhaps more sessions may have been needed, or perhaps they would have benefited more from another treatment method. The fact that no significant differences were found between groups does not support the hypothesis that EMDR might intervene on a more affective level than CBT. However, the results of this study indicate that EMDR can be used as an effective alternative for CBT in treating low self-esteem. Further research is warranted to examine whether certain patient groups might benefit more from one or the other treatment method, or a combination of both.

In conclusion, the present study is the first RCT examining the effectiveness of EMDR therapy and CBT on treating low self-esteem in a general psychiatric, adult, population. Despite the small sample size, the results suggests that, when using 10 sessions, both therapies seem effective for treating low self-esteem in patients with a wide range of psychiatric disorders in secondary mental health care. Future research will be needed to examine whether these findings can be replicated in a larger patient group, preferably using a waiting list control group. Furthermore, future studies should aim at examining which method for treating self-esteem works best for whom.

This study was carried out in accordance with the recommendations of the Medical Ethics Committee Twente with written informed consent from all subjects. All subjects gave written informed consent in accordance with the Declaration of Helsinki. The protocol was approved by the Medical Ethics Committee Twente.

BG and AvdV designed the study, collected the data and wrote the manuscript; BG performed the data analysis; IdG and AdJ made substantial contributions to the conception and design of the study and edited and revised the manuscript. All authors read and approved the final manuscript.