A mindful approach to controlling intrusive thoughts

Abstract

Intrusive thoughts of negative experiences can pose a threat to our well-being. To some extent, unwanted memories can be intentionally controlled via an executive control mechanism that downregulates the occurrence of intrusions. Mindfulness training can improve executive control. It is not known whether mindfulness training can be used as an intervention to improve intentional memory control and reduce intrusions. To this end, 148 healthy participants completed a 10-day app-based mindfulness training or an active control task. At baseline, inhibitory control and working memory were assessed as measures of executive functioning. Post-mindfulness training, intrusions were assessed via the Think/No-Think task. It was expected that mindfulness training would reduce intrusions. Furthermore, we hypothesised that this would be moderated by baseline executive functioning. Results revealed that, contrary to our hypothesis, both groups increased equally in dispositional mindfulness between baseline and post-test. As such, our exploratory analysis revealed that higher dispositional mindfulness across both groups resulted in fewer intrusions and enhanced the ability to downregulate intrusions over time. Furthermore, this effect was moderated by inhibitory control at baseline. These results provide insight into factors that can improve the ability to control unwanted memories, which could have considerable implications for treatments in psychopathologies characterized by the frequent occurrence of intrusive thoughts. PROTOCOL REGISTRATION: The stage 1 protocol for this Registered Report was accepted in principle on 11th March, 2022. The protocol, as accepted by the journal, can be found at: https://doi.org/10.17605/OSF.IO/U8SJN .

Figure 1

Outline of the study procedure. On day 1, participants completed the Mindfulness Attention Awareness Scale (MAAS), followed by measures of executive functioning (Stroop and Operation span task (OSPAN), counterbalanced in order) then concluded with the first mindfulness training (MT) or control task (S1 = Session 1). On days 2–9, participants completed daily sessions of MT or the control task (S2 = Session 2–S9 = Session 9). On day 10, participants began with their final session of the MT or control task (S10 = Session 10) and completed the post-training measures of MAAS and the 3 phases of the intentional memory control task (T/NT).

Figure 2

Outline of the T/NT task. In phase 1, participants memorised cue-target pairs and thereafter recalled the target in response to the cue. In phase 2, participants performed the T/NT task. An example of a No-Think (NT) trial is shown. Participants were first presented with the instruction (Think or Don’t Think), followed by a cue. For NT trials, participants were instructed to suppress thoughts of the target whilst the cue is on the screen. At the end of each trial, participants reported how often they had thought of the target (1 = never; 2 = briefly; 3 = often). Responses of 2 or 3 on NT trials were used to determine intrusions. Participants then completed the final recall test and recalled all targets in response to each cue. Correctly recalled cue-target pairs were calculated for each stimulus type (Think, No-Think and baseline) and used to calculate the suppression-induced forgetting index.

Figure 3

Participants in both groups increased in dispositional mindfulness. The plot displays a significant increase in dispositional mindfulness between day 1 and day 10 for both the Mindful (MT) and Control groups. The raincloud plots display the mean values within boxplots, as well as individual data points for each time point and the distribution for both groups at each time point.

Figure 4

The effect of dispositional mindfulness on intrusions is moderated by baseline inhibition. The graphs present a visualisation of the interaction effects between inhibition (Stroop) and post-test scores on the MAAS as predictors of total intrusions (A) and intrusion control, IIC (B). Simple slope analyses on the conditional effects of dispositional mindfulness (MAAS) are significant at high levels of Stroop for total intrusions and at both high and low levels of Stroop for IIC.