Limitations
RECRUITMENT
Our recruitment strategy was designed to keep the possible selection bias of mindfulness studies at a minimum, thereby increasing the generalizability of the findings. The other side of the coin, however, is that many of those allocated to MBCT did not choose to participate in the intervention after all. Similarly, SPD was used by less than half of the participants. Thus, a major limitation of the current study is that adherence to the interventions was low. Consequently, we are unable to say whether MBCT added to SPD has the potential to significantly increase successful tapering of ADM. The study was underpowered to detect a small difference in discontinuation rates. Another limitation is that we failed to systematically assess reasons for non-participation or non-discontinuation at all stages of the process when implementing our taper support strategies. For example, we do not know why participants did not use the SPD consultations as intended. Furthermore, the partnership between patient and GP was not explicitly targeted, and responsibility for making an appointment to discuss tapering was given to the patients only. In addition, the current study selected patients who all expressed a desire to discontinue their medication. Therefore, we cannot generalize our findings to all patients who are using antidepressant medication. For the aim of this study, however, it seemed most appropriate ‐ both on a practical and ethical level ‐ to select those who are motivated to taper their medication. Finally, a methodological limitation is that we used block sizes of two in our randomization schedule. Although we chose this smaller block size to prevent unequal distribution within cells that were expected to have lower numbers of GP practices due to the stratification variables (region: north, central and east Netherlands; and type of practice: single versus group), this small block size does come with a larger risk of prediction.