Neural Changes Associated With a Mindfulness-based Intervention for Young Adults With Childhood Maltreatment

Changes in the Perceived Stress Scale scores (post- intervention scores minus pre- intervention scores). Relevant time points used in the calculation include baseline scores at enrollment, and post-intervention/waiting period scores after 2 months of intervention or waiting period. Calculations of the change entail post-intervention/waiting period scores minus baseline scores for each individual subject. The Perceived Stress Scale is a 10 item scale (each responded with Likert scale 0-4), the scale score is the sum of all items, thus the full range of PSS scores is 0-40, with higher scores means worse stress. A reduction in PSS scores (i.e., the change scores being negative) indicates subjects have improved after the intervention by becoming less stressed.

Time frame: After the 8-week intervention program compared to baseline measurement, or the same time as the intervention group for subjects on the waiting list.

Changes in the mindfulness level as measured by the Mindful Attention Awareness Scale (post-intervention scores minus pre-intervention scores). Relevant time points used in the calculation include baseline scores at enrollment, and post-intervention/waiting period scores after 2 months of intervention or waiting period. Calculations of the change entail post-intervention/waiting period scores minus baseline scores for each individual subject. The MAAS is a 15-item scale each responded with Likert scale 1-6; the MAAS score calculated as the mean of all items, thus the full range of the score is 1-6, with higher scores meaning more mindful. An increase in MAAS score (i.e., a positive score change )means the subject has improved after the intervention by becoming more mindful.

Time frame: After the 8-week intervention program compared to baseline measurement, or the same time as the intervention group for subjects on the waiting list.

Gray matter density of the right hippocampus is calculated from anatomical MRI data with the SPM software. Percent changes of gray matter density is calculated for each subject. Relevant time points used in the calculation include baseline values at enrollment, and post-intervention/waiting period values after 2 months of intervention or waiting period. Calculations of the change entail post-intervention/waiting period values minus baseline values, then divided by the baseline values to obtain the percent change measure.

Time frame: 2 months

Population: Subjects who completed both baseline and post-intervention/waiting period were entered into analyses. 6 Subjects from the waiting list control group completed a third MRI after completing the mindfulness intervention.