This study addressed the role of baseline self-efficacy and mental health symptoms on treatment outcomes of two CBT-based interventions for employees who are absent due to CMDs. This study builds upon an earlier study in which we compared the effectiveness of two psychotherapeutic interventions: W-CBT that integrated work aspects early into the treatment and R-CBT [
9]. In a quasi-experimental design, 12-month follow-up data of 168 employees were collected with respect to RTW and the course of mental health complaints. We expected that individuals with high baseline work-related self-efficacy (RTW-SE) and low baseline depressive symptoms and anxiety would benefit more from W-CBT, compared with R-CBT.
Influence of Baseline Self-Efficacy on Treatment Outcomes
The benefits of W-CBT, compared with R-CBT, for partial RTW were not dependent upon individuals’ baseline level of self-efficacy. However, the benefits for full RTW were more pronounced among those with high baseline self-efficacy. For individuals with high self-efficacy, full return occurred 56 days earlier in the W-CBT group compared with the R-CBT group, and 79 days earlier compared to their low self-efficacious counterparts in W-CBT. W-CBT and R-CBT were equally effective in promoting full RTW among those low in self-efficacy. Moreover, the two interventions resulted in a comparable decline of mental health complaints, irrespective of baseline self-efficacy. Hence, only the benefits of W-CBT for full RTW were associated with baseline self-efficacy.
Whisman [
28] proposed that cognitive therapies capitalize on pre-existing strengths and skills and that individuals with relatively high levels of capabilities and positive learning histories would therefore benefit more from cognitive therapy. Our results suggest that this may be particularly true for W-CBT, which offers additional challenges to clients by systematically addressing work and RTW. Individuals who possess high levels of RTW-SE may be better able to deal with these challenges, and may in this way combat dysfunctional cognitions and secure success experiences.
It is interesting to relate our results to a recent large-scale, Norwegian study that examined W-CBT in combination with employment services, among individuals struggling with work participation due to CMD [
42]. Particularly among individuals depending on long-term benefits, the combined intervention resulted in higher work participation. Although the scope and sample of this study differed from our study, the results point at the relevance of integrating mental health and employment services (see also [
43]). A related study using the same sample [
44] showed that uncertain and unfavourable RTW expectations predicted future dependence on benefits, particularly for those with a favourable work status at baseline (i.e., those not depending on long-term benefits). In line with the characteristics of our W-CBT intervention, the authors recommend addressing RTW expectations in an early phase during RTW interventions.
Influence of Baseline Depression and Anxiety on Treatment Outcomes
The effectiveness of W-CBT, compared with R-CBT, did not depend on baseline levels of depressive complaints or anxiety. Unlike expected, the positive effects of W-CBT on partial and full RTW were not more prominent among those with lower baseline levels of depression or anxiety. Furthermore, irrespective of baseline depression or anxiety, both interventions resulted in a decline of mental health complaints (see also [
9]).
It is important to note that more serious disorders, such as major depressive disorder, were not part of our inclusion criteria. It seems then that within the restricted range of CMDs included in our study, the severity of the disorder does not influence treatment success. Perhaps if more serious disorders had been included, we would have found comparable results as previous studies which identified symptom severity as a significant predictor for less favourable treatment outcomes (e.g., [
28,
29]). However, a study by Hees et al. [
45] demonstrated favourable effects of work-focused therapy on the course of mental health complaints among employees with a major depression.
Theoretical and Practical Implications
Our study contributed to the scarce knowledge on RTW interventions for employees who are absent due to CMDs, in relation to baseline self-efficacy and mental health symptoms. This study revealed the influence of baseline self-efficacy on the benefits of W-CBT intervention for full RTW. It also showed that baseline depressive symptoms and anxiety had no effect on treatment outcomes. With these results, we hope to have increased our insight into the factors that determine ‘what kind of intervention works for whom’ [
19,
20]. Practitioners could use this kind of information to motivate their clients in the RTW process. For those with high initial levels of RTW-SE, practitioners could for example emphasize the benefits in terms of successful RTW that are likely to occur (e.g., as part of the rationale for providing W-CBT). Below we describe how the insights from our study may encourage psychotherapists to use W-CBT as a preferred intervention, and adapt interventions to clients’ individual needs.
Although employees with low baseline self-efficacy did not benefit from W-CBT in terms of full RTW, this intervention did promote partial RTW and did not hinder the recovery of their mental health problems. Considering the potential benefits of W-CBT for partial RTW and the relatively low costs of adding work-related components, we would therefore recommend W-CBT for employees with CMD, irrespective of baseline levels of self-efficacy. A focus on (return to) work might also offer psychotherapists a convenient context in which CBT techniques can be applied to achieve regular psychotherapy treatment goals and stimulate RTW. Elevated levels anxiety or depressive complaints at baseline do not seem to hinder the effectiveness of W-CBT for individuals with CMD.
To tailor W-CBT to low self-efficacious individuals it may be fruitful, however, to add extra exercises or components that may help these individuals prepare for their RTW. This is not to say that RTW issues should not be addressed in an early stage for those with low self-efficacy, but that perhaps extra efforts are needed. Bandura [
46] has proposed several strategies that can be used to enhance self-efficacy, whereby personal mastery is considered the most potent source of self-efficacy. For those with low self-efficacy, however, it may be better to start with ‘safer’ sources of self-efficacy (e.g., [
47]), such as vicarious learning (e.g., learning what similar clients did to RTW), verbal persuasion (e.g., receiving verbal information about the relevance of coping skills in the work setting), and arousal management (e.g., learning techniques to regulate one’s emotional arousal). These sources of self-efficacy may be less challenging for individuals compared with active engagement in activities at the workplace (i.e., personal mastery). Furthermore, considering the multifactorial nature of the RTW process for employees with CMD [
1], we would recommend therapists to be particularly alert to obstacles in the workplace, such as conflicts with supervisors [
24]. Awareness of obstacles may encourage psychotherapists and their clients to come up with strategies to overcome these obstacles (for instance by proposing mediation or transfer to another supervisor, in case of conflicts). Perhaps with the necessary work adjustments, individuals with low-self efficacy are better able to use W-CBT to their advantage.
In general, W-CBT appeared to be superior in terms of partial and full RTW, without negative consequences for the course of mental health complaints [
9]. We would like to connect these findings to some recent trials concerning RTW interventions for individuals with CMD. Some studies found no beneficial effects on work participation and mental health, such as an Individual Placement and Support intervention for individuals with mood and anxiety complaints [
48], an RTW intervention for primary care patients on sick leave due to CMD [
49], and an RTW program for employees without an employment contract, sick-listed due to CMD [
50]. Other studies did find benefits in terms of employment and mental health, such as an individual enabling and support intervention for affective disorders [
51], and a combined intervention for individuals struggling with work participation due to CMD [
42]. These somewhat conflicting findings point to the relevance of further disentangling the specific mechanisms and characteristics of successful RTW interventions for individuals affected by CMD, in relation to client characteristics.
Limitations and Suggestions for Future Research
An important limitation of our study concerns the use of a quasi-experimental design. As we did not randomly assign departments, and allocation of participants was based on proximity to a department, potential resulting biases should be kept in mind when interpreting our results. However, several aspects of our study may substantiate the robustness and validity of our findings. Allocation of clients did not involve content-driven choices. Moreover, randomization checks revealed that the two conditions did virtually not differ with respect to socio-demographic variables, therapeutic characteristics, and work characteristics. The only baseline differences that appeared concerned clients’ marital status and the time on waiting list (for which we corrected in our analyses when significant). Although we cannot fully rule out that clients in the conditions may have differed on other variables, such as for instance neighbourhood characteristics, we believe that it is not very likely that these other variables would explain the differential effects of our interventions. Nevertheless, it would be important to replicate our results using a fully randomized design.
A second point of concern is our limited sample size (N = 168). We did find significant interactions in our sample, while moderator effects are generally difficult to identify statistically [
52]. Nevertheless, some non-significant effects were in the expected direction and might have been significant with a larger sample size. For future studies, we would recommend to employ larger sample sizes. Effects that would be particularly interesting to pursue further would pertain to the prediction of partial RTW.
Another limitation concerns the measurement of our mental health variables. Substantial dropout occurred, although this was not selective for most of the variables studied and we used multilevel analyses in order to deal with missing data [
41]. Moreover, we did not have the opportunity to measure psychological well-being in the longer-term and at crucial RTW events (e.g., during increases in work hours). Future research could also pay attention to the long-term quality of RTW (e.g., and the views of different stakeholders on successful RTW) (see also [
9,
53]).
It is also important to take into account that low efficacy cognitions may reflect individuals’ work environment and individual characteristics that are beyond individuals’ control [
9,
24]. Although CMDs may affect individuals’ ability to have realistic efficacy cognitions, trying to alter realistic low self-efficacy beliefs might actually harm individuals. For instance, when individuals are encouraged to adopt goals that would go far beyond their reach or control, failure may occur. This risk may be reduced by gradual return and by choosing adequate goals that target controllable factors. Nevertheless, practitioners and future researcher might want to assess the realism of clients’ efficacy cognitions, for instance, by relating these cognitions to clients’ (mal)functioning at work before the onset of mental health problems, by examining relevant work factors that are beyond clients’ control, and by exploring the options for employers to improve individuals’ work environment [
9,
24]. Based on this assessment, additional professional training, adaptations in individuals’ work environment by the employer, or permanent job changes may be recommended to create a better person-job fit.
Future studies may also want to examine how interventions can be further adapted to help low self-efficacious individuals RTW. Future research might incorporate a wider variety of self-efficacy enhancing methods, as described above, such as vicarious learning from peers by using a group setting.