- Definitions: What is return to work after mental ill health?
- Why is ‘return-to work’ after sick leave due to mental ill health an important issue?
- Factors of influence on RTW after sick leave due to mental health problems
- Evidence based interventions to enhance RTW
- Further reading
The article will describe factors of influence on return to work RTW and evidence-based interventions that enhance return to work (RTW) after sick leave due to common mental health disorders (CMD). First the concepts of both RTW and CMD are outlined. Second, the sense of urgency for effective RTW interventions for workers with CMD is briefly described. Third, a variety of predictors of RTW are presented with respect to the disorder, personal factors, and environmental factors. Lastly, a brief description of usual care and an overview of effective RTW interventions will be provided. A final paragraph will provide some conclusions as to which measures at what level appear to be effective in return to work after sick leave due to mental health disorders.
This article will focus on individuals returning to work with common mental health disorders with both work-related and non-work related causes. Common mental health problems include for example depression, anxiety, adjustment disorder and other stress-related disorders. Return to work (RTW) can be defined as: “Resuming work tasks/work hours after a period of sick leave". Although definitions of RTW vary according to disciplines or socio-legal contexts, most researchers use criteria such as work status (present/absent from work), number of hours worked or time until resuming contractual hours (with equal earnings) A few studies have recently paid more attention to the quality of RTW (e.g. work functioning and the sustainable RTW) .
According to the OECD mental health at the workplace is considered to an upcoming priority challenge for the labour market . The costs of mental ill-health for the individuals concerned, employers and society at large are very large. A conservative estimate from the International Labour Organisation (ILO) put them at 3-4% of the gross domestic product in the EU. Most of these costs do not occur within the health sector.
Common mental disorders (CMD) are highly prevalent in the working population. For example, the 12-month prevalence for having any depressive, anxiety or alcohol related problem is 9% in the European working population . For less severe complaints such as burnout these rates can even reach 16% 
People with CMD often experience difficulties in meeting work demands with respect to Psychological Demands│mental performance (e.g, concentrating), interpersonal tasks (e.g., handling emotions) or handling work pressure (e.g., keeping up work pace or quality, energy regulation setting one’s personal boundaries) .
CMD often result in long term sick leave spells, and the overall employment rates of people with CMD is around 10-15% lower than among people with no mental disorder . In addition, the OECD research  shows that while the prevalence of mental ill-health overall is not rising, an increase in disability benefit claims and absenteeism because of mental ill-health is visible. Furthermore, 20 to 30% of the workers with CMD who return to work experience recurrent sickness absence due to mental health problems . Considering the individual suffering and economic burden associated with long-term sick leave for both employers and society, it is important that effective RWT interventions are implemented.
In order to develop effective interventions and screen for cases at risk for long-term sick leave it is important to know what factors predict RTW. Empirical evidence underlines the multifaceted nature of RTW and has demonstrated the impact of disorder characteristics (e.g., severity of depressive symptoms), other individual characteristics (e.g., age), and environmental factors (e.g., supervisor behavior) on RTW. Below we present the predictors of RTW in relation to each of these levels that have been reported in systematic reviews . It is important to note that predictors can vary according to the type of disorder or the legislative context
Reviews  conclude that more severe symptoms, longer duration of a mental ill health episode and co-morbid physical or mental health problems predict unfavorable RTW outcomes. In addition, compared with other common mental health disorders, employees with a major depression also have lower chances for successful RTW. Especially the relation between duration of depressive symptoms and functioning in work stresses the importance of a rapid treatment of these mental ill health symptoms.
Symptom reduction contributes to better RTW, in a way that symptoms’ improvement is followed, after a substantial time lag, by an improvement of work functioning  However it is important to note that other factors play an important role as well. For example, among depressed employees only 10% of successful RTW could be explained by symptom reduction . In addition, treatment that is adequate in reducing symptoms usually have limited or no effect on occupational outcomes such as RTW . So, it seems that symptom reduction is no guarantee for RTW. Several intervention studies indeed show that symptom recovery and the process of RTW are partly independent .This means that for individuals who experience similar symptom levels, one person might return to work while the other person will not.
Reviews  have related several demographic characteristics to lower RTW chances such as: higher age (e.g. above 50), lower education, a prior history of sick leave, and marital status (widowed, divorced or single). Results on gender are inconclusive, but on average slightly higher RTW chances for men have been reported. However, these personal factors cannot be changed in an intervention.
Modifiable personal factors that predict RTW according to the above mentioned reviews include: low self-esteem, feelings of hopelessness about the future, low social functioning, and recovery expectations such as self-efficacy. Recent longitudinal studies (published after the aforementioned reviews) confirm the role of work related self-efficacy as a robust RTW predictor in the heterogeneous population of employees with CMD .
Some personal factors seem of importance but are under-researched in longitudinal quantitative studies (and therefore not included in the abovementioned reviews). Several qualitative studies show the importance of personality characteristics (e.g. perfectionism, high sense of responsibility), work life-balance, the ability to set personal limits, and difficulty deciding the appropriate time to RTW as important factors for RTW (see, also for a more in depth discussion:  and for a meta-analysis).
With respect to work-related characteristics systematic reviews report that reorganizational stress, injury at work, unemployment, and lower pre-sick leave functioning at work reduce the chance for RTW. Among employees with mental disorders other than depression, RTW chances are higher when supervisors initiate frequent contact (e.g., once every 2 weeks) with non-depressed employees .
It may well be the case that other work related characteristics such as high mental work demands play a role in the RTW process, but work characteristics have not been studied that often. Qualitative research underlines, for example, organizational characteristics that complicate work adaptations during the RTW process and the influence of social support at the workplace (see 24 for a meta-analysis). Not all employers can or are willing to offer work adaptations such as reduced work hours, workload or responsibilities. In addition, the workplace culture (e.g. with a strong focus of productivity and performance-oriented goals) can result in a suboptimal implementation of the accommodation agreements . The importance of active support from the supervisor in the RTW process (e.g. facilitate work adjustments), has been identified as a strong predictor of successful RTW in quantitative studies as well  .
Furthermore, one could presume that work characteristics needed to prevent the onset of sick leave due to mental health issues are of importance for a successful RTW (e.g., balanced work demands, decision latitude, and social support). The recent report from the international “Organisation for Economic Co-operation and Development (OECD)" stresses for example the importance of good management for mental health in the workplace. For example a line manager or supervisor who supports the worker, gives adequate feedback and recognizes the work effort is extremely important in facilitating the RTW process. In the study by Houtman & Blatter this was the most significant facilitator of RTW. .
Beyond organizational factors, several governments from Western countries increasingly recognize the importance of effective policies and legislative that keep people with mental ill-health in employment. Regarding tertiary interventions the importance of activating disability policies is underlined: The requirements for both the benefit applicants and benefit authorities should be strengthened towards a focus on work capacities. Research across several European countries indeed shows that integrated disability policies (that focused on both the compensation of income and had a focus on reintegration) were more successful than welfare systems that focused on income replacement only, particularly for the low-educated (; see also figure 1).
Other policy advise that can be found in the OECD reports is for example:
- Better access to mental health services.
- Improving the focus on vocational issues in mental health care.
- Stimulate coordinated support (e.g., requiring better co-operation between employment services, health services, and benefit authorities).
- Improving skills and knowledge of general practitioners on mental health issues (e.g. diagnosis of CMD and inform them that prescribing “rest and being on sick leave" is potentially harmful to a patient with CMD).
- Allowing partial sick leave. Countries that use policies allowing partial sick leave report positive outcomes on reducing disability claims due to CMD (such as Sweden, Denmark, Norway and the Netherlands).
- Adapt systems and workplace policies in a way that the disclosure of a mental disorder is supported. Reduction of the stigma on mental ill health might increase the willingness of employees to receive adequate care.
It is estimated that about 80% of people with CMD will not receive any treatment . If they do seek support they will mostly receive care from their general practitioner (GP). GP’s are, however, not sufficiently trained to deal with CMD’s leading to under diagnosis, inadequate treatment for symptom reduction, and stimulating sick leave as they generally prescribe patients ‘rest’ in combination with medical (non-work related) interventions .
A substantial part of employees on sick leave with CMD will receive clinical treatment from mental health professionals such as cognitive behavioral therapy or anti-depressants that successfully reduces complaints . Although work is a central part of a people’s lives and an important element in recovery, standard clinical treatments for mental ill health pay little attention to work related problems . For example, clinical guidelines or current clinical practice include no systematic approaches for employers (e.g. contacting them to inform about relevant workplace adaptations). Furthermore, mental health care quality indicators do not include any element of employment. Similar to GP’s most mental health care providers will adopt a symptom contingent approach. A focus on symptoms instead of resources can reinforce illness identity and non-work identity of the employees, which in turn can have a negative effect on the RTW process .
Some employees on sick leave will additionally receive support from occupational health providers (such as occupational physicians) or caseworkers from the employment and reintegration services. Information on the number of people with common mental disorders in such programmes and their effectiveness is very limited . Not many vocational support services gather outcome data systematically that would allow evaluation of their services. Some of the effective interventions described below are, however, issued by professionals with more focus on work issues than GP’s or mental health providers (e.g. labour experts, occupational physicians, occupational therapists).
Finally, in nowadays practice cooperation and communication between the different stakeholders in the RTW process is not optimal and this might slow down the RTW process . Stakeholders include for example the sick listed workers and their families, supervisors, healthcare providers, insurers and labour representatives. All stakeholders might have different views and –sometimes conflicting - interests in the RTW process. This can result in opposing advice, recommendations and demands that are difficult to deal with for an employee on sick leave: “This lack of coordination can cause a feeling of confusion and uncertainty about how and when to return to work" .
Effective RTW interventions
There is little research available that can clearly demonstrate the effectiveness of RTW programmes. A systematic review and meta-analysis of randomized controlled trials  assessed the effectiveness of existing workplace and clinical interventions aimed at enhancing RTW of CMD. Results showed that interventions did not lead to improved RTW rates but reduced the number of sick-leave days. Research on the types of RTW interventions shows that for depressed employees the following interventions are more effective to enhance RTW compared with other treatment. First, a combination of anti-depressant medication and psychodynamic therapy was more effective than medication alone . Secondly, work focused treatment (psychological and occupational therapy) resulted in more successful RTW  compared with usual care but there are no differences in effect between the different types of psychological interventions such as problem-solving therapy or cognitive behavioural therapy. For workers with adjustment disorders, Arends and colleagues  conclude that problem solving therapy can result in faster part-time resumption of work tasks (partial RTW). In order to prevent the onset of mental health problems and related sick leave, organizational level interventions have been studied.
A closer inspection of the RTW interventions that were effective compared to usual care  allows the identification of some elements that they have in common:
- All interventions combined cognitive behavioral techniques with a focus on work. The work focus consisted of improving problem-solving coping or coping strategies related to return-to-work barriers.
- In addition, there was a focus on graded RTW starting in an early phase of absenteeism (e.g. after 1-2 months even when symptoms had not fully recovered). In this way the contact with the workplace was restored as quickly as possible, in order to reduce the threshold for RTW. Graded RTW and early partial RTW are acknowledged by several authors as potential successful intervention elements . However, there is a risk of subdividing the RTW process into (too) small steps. When an employee feels up to full RTW or larger RTW steps (e.g. has no fear of failure, is confident of implementing coping strategies), there is probably no need to follow a (highly) graded process. A study by Noordik that shares the aforementioned intervention elements for example was not effective, likely because it stimulated too small steps, while people did not need them .
- A tailored RTW plan was drawn to guide the graded RTW process. This plan consists of a step by step approach that gradually increases work hours and task complexity until full RTW is achieved. This gradual approach (with work adjustments) can enhance success experiences when returning to work. Beneficial elements of work (e.g. social contact, structure, meaningful daily activity) are incorporated in the RTW plan in order to facilitate recovery.
- Suitable workplace adjustments can support the RTW. It is important that such workplace adjustments are best recommended by a professional who has a good understanding of the working environment and the patient’s job. Examples might include modifying tasks, offering flexible working hours/patterns, allowing time to attend medical appointments, additional training, etc.
- All these interventions were targeted at the individual sick listed worker. Work place adaptations (e.g. reduced work hours, other tasks) were arranged as much as possible via the employee. However we have to note that the legislative context in which these interventions were offered often obliged employers to (actively) facilitate work adjustments. Several studies have stressed the importance of employers facilitating work adaptations for successful RTW  . In this way the mental health problem and sickness absence are not only interpreted as an individual problem that should be solved with individual adaption strategies, but that work place changes are also (temporarily) necessary.
- The timing of the intervention seems to play a role as well. Research shows that early intervention and early partial RTW is important to reduce the threshold for RTW and avoid psychological complaints from becoming worse. Prolonged sick leave duration by itself seems to decrease the chances of RTW . For example, those on sick leave for longer than 6 months were found to have only 50% chance to RTW . The RTW chances decrease for those with a depression (mood disorder) when they are on sick leave for 3 months or more . On the other hand, interventions should not be offered too early . First of all, there is a risk of overtreatment. Offering an intervention too fast after the onset of sick leave might result in people postponing full RTW compared to a situation without treatment (risk of medicalization of the problem). In addition, people might need some weeks off from work as a coping strategy during a crisis phase.
- Finally the type of intervention provider seems to matter. The evidence is inconclusive, but it seems that not all professionals are able to integrate work aspects. For an adequate work focus insight in workplace aspects and/ or RTW targets (e.g the professional is paid by the employer) seem to be necessary. For example, interventions that included promising elements (like problem solving and graded RTW) provided by General Practitioners (GP’s) or Social Workers were not effective, possibly because of their distance to the workplace. Insight and focus on work aspects can either follow by the nature of the profession (e.g. for labour experts, occupational therapist, occupational physicians) or by an elaborate work anamneses for those with a more distal relation to the employees’ workplace.
Effects of RTW interventions on mental health
Both employees and care providers express the concern that (early) RTW might evoke an increase of psychological symptoms. Hence, it is important to know what the effects of RTW interventions are on mental health. Several studies that describe effective RTW interventions have also reported on mental health outcomes. These studies show a decline of mental health problems over time, both for employees who received a RTW intervention and those who received regular care (e.g., . As a reduction of mental health complaints occurred irrespective of treatment type, one can conclude that effective RTW interventions have no negative side effects on symptom reduction. For depressed patients effective RTW or stay at work interventions might even improve mental health .
It can be concluded that individual interventions with a focus on the workplace and RTW can enhance RTW. Effective ingredients of these interventions seem to be: active support of RTW from the supervisor; early graded RTW and activating cognitive behavioral therapy (CBT) based and/or problem solving techniques (e.g. learning coping skills to deal with RTW barriers). No clear evidence is available for the effectiveness of interventions directly targeted at the workplace.
 Hees, H.L., Nieuwenhuijsen, K, Koeter M.W.J., , Ute Bú ltmann, U, Schene, A.H. (2012). Towards a New Definition of Return-to-Work Outcomes in Common Mental Disorders from a Multi-Stakeholder Perspective, PLoS ONE 7(6): e39947. doi:10.1371/journal.pone.0039947
 OECD (2012), Sick on the Job? Myths and Realities about Mental Health and Work, Mental Health and Work,OECD Publishing .http://dx.doi.org/10.1787/9789264124523-en
 Alonso J, Angermeyer MC, Bernert S, Bruffaerts R, Brugha TS, Bryson H et al. Prevalence of mental disorders in Europe: results from the European Study of the Epidemiology of Mental Disorders (ESEMeD) project. Acta Psychiatr Scand. 2004;109(Suppl.420):21–7.
 Boedeker, W., & Klindworth, H. (2007). Hearts and minds at work in Europe. A European work-related public health report on cardiovascular diseases and mental ill health. Essen, Germany: BKK Bundesverband.
 Laitinen-Krispijn S, Bijl RV. (2000). Mental disorders and employee sickness absence: the NEMESIS study. Netherlands Mental Health Survey and Incidence Study. Soc Psychiatry Psychiatr Epidemiol. ;35(2):71–77
 Gärtner FR. Work functioning impairments due to common mental disorders. Measurement and prevention in nurses and allied health professionals. s.l.: s.n.; 2012. 266p. ISBN 9789491043062. Dissertation University of Amsterdam.
 Lagerveld, S.E., Blonk, R.W.B., Brenninkmeijer, V., & Schaufeli, W.B. (2010). Return to work among employees with mental health problems: Development and validation of a self-efficacy questionnaire. Work & Stress, 24, 359-375.
 Koopmans PC, Bultmann U, Roelen CA, Hoedeman R, van der Klink JJ, Groothoff JW (2011). Recurrence of sickness absence due to common mental disorders. International Archives of Occupational and Environmental Health;84(2):193–201.
 Blank L, Peters J, Pickvance S, Wilford J, Macdonald E. A systematic review of the factors which predict return to work for people suffering episodes of poor mental health. Journal of Occupational Rehabilitation 2008;18(1):27–34
 Cornelius, L. R., van der Klink, J. J. L., Groothoff, J. W., & Brouwer, S.(2011). Prognostic factors of long term disability due to mental disorders: A systematic review. Journal of Occupational Rehabilitation, 21, 259–274. doi:10.1007/s10926-010-9261-5
 Lagerveld, S.E., Bültmann, U., Franche, R.L., van Dijk, D.J.H., Vlasveld, M.C., van der Feltz-Cornelis, C.M., Klink van der JL, Huijs J, Dijk van FJH, Blonk RWB, Nieuwenhuijsen K. (2010). Factors associated with work participation and work functioning in depressed workers: A systematic review. Journal of Occupational Rehabilitation, 20, 275-292.
 Stress Impact (2006). Integrated report of Stress Impact: On the impact of changing social structures on stress and quality of life: Individual and social perspectives. Retrieved from www.surrey.ac.uk/Psychology/stress-impact/publications
 Werff E van der, Verboom CE, Penninx BWJH, Nolen WA,J (2010) Explaining heterogeneity in disability associated with current major depressive disorder: Effects of illness characteristics and comorbid mental disorders. J Affect Disord. 127:203-21
 Nieuwenhuijsen K, Bültmann U, Neumeyer-Gromen A, Verhoeven AC, Verbeek JHAM, van der Feltz-Cornelis CM. Interventions to improve occupational health in depressed people. Cochrane Database of Systematic Reviews 2008, Issue2. [DOI: 10.1002/14651858.CD006237.pub2]
 Van der Klink JJL, Blonk RWB, Schene AH, van Dijk, FJH. (2003). Reducing long term sickness absence by an activating intervention in adjustment disorders: a cluster randomized controlled design. Occupational and Environmental Medicine; 60(6):429–37. [DOI: 10.1136/oem.60.6.429;PUBMED: 12771395]
 Blonk RWB, Brenninkmeijer V, Lagerveld SE, Houtman ILD. (2006). Return to work: a comparison of two cognitive behavioural interventions in cases of work-related psychological complaints among the self-employed. Work & Stress 2006;20(2):129–44. [DOI: 10.1080/ 02678370600856615]
 Lagerveld, Suzanne E; Blonk, Roland W B; Brenninkmeijer, Veerle; Wijngaards-de Meij, Leoniek; Schaufeli, Wilmar B (2012). Work-Focused Treatment of Common Mental Disorders and Return to Work : A Comparative Outcome Study. Journal of occupational health psychology; 17 (2), 220-234
 Noordik E, van der Klink JJ, Geskus RB, de Boer MR, van Dijk FJH, Nieuwenhuijsen K(2013). Effectiveness of an exposure-based return-to-work program for workers on sick leave due to common mental disorders: a cluster-randomized controlled trial. Scandinavian Journal of Work Environ Health; 1;39(2):144-54. doi: 10.5271/sjweh.3320.
 Nieuwenhuijsen K, Noordik E, van Dijk FJH, van der Klink JJ, Return to Work Perceptions and Actual Return to Work in Workers with Common Mental Disorders. J OCCUP REHABIL 2013;ahead of print
 Huijs, J.J.M, Koppes, L.J., Taris, T.W., Blonk, R.W.B. (2012). Differences in Predictors of Return to Work Among Long-Term Sick-Listed Employees with Different Self-Reported Reasons for Sick Leave. Journal of Occupational Rehabilitation;22(3):301-11. DOI 10.1007/s10926-011-9351-z
 Brouwer, S, Reneman, M.F., Bultmann, U, van der Klink, J.J.L., Groothoff, J.W. (2010). A Prospective Study of Return to Work Across Health Conditions: Perceived Work Attitude, Self-efficacy and Perceived Social Support. J Occup Rehabil, 20:104–112. DOI 10.1007/s10926-009-9214-z
 Noordik E, Nieuwenhuijsen K, Varekamp I, van der Klink JJ, Van Dijk FJ (2011). Exploring the return-to-work process for workers partially returned to work and partially on long-term sick leave due to common mental disorders: a qualitative study. DISABIL REHABIL;33 (17-18):1625-1635
 de Vries, G., M.W.J. Koeter b, U. Nabitz , H.L. Hees , A.H. Schene. (2011), Return to work after sick leave due to depression; a conceptual analysis based on perspectives of patients, supervisors and occupational physicians, J. Affect. Disord., doi:10.1016/j.jad.2011.06.035
 Andersen MF, Nielsen KM, Brinkmann S, (2012) Meta-synthesis of qualitative research on return to work among employees with common mental disorders. Scand J Work Environ Health;38(2):93-104. doi:10.5271/sjweh.3257
 Oomens, P.C.J., Huijs, J.J.M., Blonk, R.W.B. (2009). Obstakels in werk: wat belemmert werkhervatting bij werknemers met psychische klachten? [obstacles in the workplace: what impedes return to work among employees with mental healht problems.]Tijdschrift voor Bedrijfs- en Verzekeringsgeneeskunde, 17(6):231-236.
 Houtman, I. & Blatter, B. (2005).Predicting Return to Work from employees' absent behaviour in cases of psychosocial problems. Occupational Health Psychologist; 2(3): 8-12.
 Houtman, I. & Blatter, B. (2005).Predicting Return to Work from employees' absent behaviour in cases of psychosocial problems. Occupational Health Psychologist; 2(3): 8-12.
 Anema, J.; Jettinghoff, K.; Houtman, I.; Schoemaker, C.; Buijs, P.; Berg, R. (2006). Medical Care of Employees Long-Term Sick Listed Due to Mental Health Problems: A Cohort Study to Describe and Compare the Care of the Occupational Physician and the General Practitioner . Journal of Occupational Rehabilitation, 16(1),38-49(12).
 Buijs PC, van Dijk FJ, Evers M, et al. Managing work-related psychological complaints by general practitioners, in coordination with occupational physicians: a pilot study. Ind Health 2007; 45(1): 37–43
 Butler, A. C., Chapman, J. E., Forman, E. M., & Beck, A. T. (2006). The empirical status of cognitive-behavioral therapy: A review of meta-analyses. Clinical Psychology Review, 26, 17–31. doi:10.1016/j.cpr.2005.07.003
 Kessler, R. C., Berglund, P., Demler, O., Jin, R., Koretz, D., Merikangas, K. R., . . . Wang, P. S. (2003). The epidemiology of major depressive disorder: Results from the National Comorbidity Survey Replication (NCS-R). Journal of the American Medical Association, 289, 3095– 3105. doi:10.1001/jama.289.23.3095
 ten Have, M., de Graaf, R., Vollebergh, W., & Beekman, A. (2004). What depressive symptoms are associated with the use of care services? Results from the Netherlands Mental Health Survey and Incidence Study (NEMESIS). Journal of Affective Disorders, 80, 239–248. doi:10.1016/S0165-0327(03)00132-0
 Kidd, S. A., Boyd, G. M., Bieling, P., Pike, S., & Kazarian-Keith, D. (2008). Effect of a vocationally-focused brief cognitive behavioural intervention on employment-related outcomes for individuals with mood and anxiety disorders. Cognitive Behaviour Therapy, 37, 247–251. doi:10.1080/16506070802473189
 Pomaki G, Franche RL, Murray E, Khushrushahi N, Lampinen TM (2012). Workplace-based work disability prevention interventions for workers with common mental health conditions: a review of the literature. J Occup Rehabil.;22(2):182-95. doi: 10.1007/s10926-011-9338-9.
 Friesen MN, Yassi A, Cooper J. Return-to-work: The importance of human interactions and organizational structures. Work 2001; 17: 11–22.
 Arends I, Bruinvels DJ, Rebergen DS, Nieuwenhuijsen K, Madan I, Neumeyer-Gromen A, Bültmann U, Verbeek JH. (2012). Interventions to facilitate return to work in adults with adjustment disorders. Cochrane Database of Systematic Reviews, Issue 12. Art. No.: CD006389. DOI: 10.1002/14651858.CD006389.pub2
 Hees HL, de Vries G, Koeter MWJ, Schene, A.H. (2013). Adjuvant occupational therapy improves long-term depression recovery and return-to-work in good health in sick-listed employees with major depression: results of a randomised controlled trial. Occup Environ Med 2013;70:252–260. doi:10.1136/oemed-2012-100789
 Schene AH, Koeter MWJ, Kikkert MJ, Swinkels JA, McCrone P. (2007). Adjuvant occupational therapy for workrelated major depression works: randomized trial including economic evaluation. Psychological Medicine;37(3):351–62 https://pubmed.ncbi.nlm.nih.gov/17112401/
 Van Oostrom S H, VanMechelen W, Terluin B, De Vet H C W, Knol D L, Anema J R. (2010). A workplace intervention for sick-listed employees with distress: Results of a randomized controlled trial. Occupational and environmental medicine, 67(9):596–602.
 Willert MV, Thulstrup AM, Bonde JP.(2011). Effects of a stress management intervention on absenteeism and return to work--results from a randomized wait-list controlled trial. Scandinavian Journal of Work, Environment & Health;37(3):186–95.
 Hogelund J, Holm A, McIntosh J(2010). Does graded return-to-work improve sick-listed workers’ chance of returning to regular working hours? J Health Econ;29:158–69.
 Roelen CA, Norder G, Koopmans PC, van Rhenen W, van der Klink JJ, Bültmann U. (2012). Employees sick-listed with mental disorders: who returns to work and when? J Occup Rehabil.;22(3):409-17. doi: 10.1007/s10926-012-9363-3.
 Bakker IM, Terluin B, van Marwijk HW, van der Windt, DA, Rijmen F, van Mechelen W, et al. (2007). A cluster-randomised trial evaluating an intervention for patients with stressrelated mental disorders and sick leave in primary care. PLoS Clinical Trials;2(6):e26. [DOI: 10.1371/journal.pctr.0020026; PUBMED: 17549228].
 Brouwers EP, Tiemens BG, Terluin B, Verhaak PF.(2006) Effectiveness of an intervention to reduce sickness absence in patients with emotional distress or minor mental disorders: a randomized controlled effectiveness trial. General Hospital Psychiatry;28(3):223–9. [DOI: 10.1093/eurpub/ckl099; PUBMED: 16675365]
 Lerner D, Adler D, Hermann RC, Chang H, Ludman EJ, Greenhill A, Perch K, McPeck WC, Rogers WH.(2012). Impact of a work-focused intervention on the productivity and symptoms of employees with depression. J Occup Environ Med.;54(2):128-35. doi: 10.1097/JOM.0b013e31824409d8.
IDMSC – International Disability Management Standards Council (no date), home page. Retrieved on 28 August 2013, from: http://www.idmsc.org