MindLog EMA

Four times per day for 30 days, participants used the MindLog iOS/Android app, with notifications sent at 8 a.m., 12 p.m., 4 p.m., and 8 p.m. to complete the following information. At each time point, the EMA could be completed within 2 min.

Participants rated depression and anxiety on 7-point Likert scales. For depression, participants responded to “How happy vs. sad/ depressed do you feel right now?” with the “Happy” label anchor next to score of 1 and the “Sad or Depressed” label anchor next to score of 7. For anxiety, participants responded to “How relaxed vs. anxious do you feel right now?” with the “Relaxed” label anchor next to score of 1 and the “Anxious” label anchor next to score of 7.

Similar to the internal attention cognitive assessment, at each EMA participants completed a rapid 30-s assessment in which they were requested to tap the mobile screen after each full breath (inhale plus exhale). Recent research shows that such monitoring can serve as a basic assay of breath-focused mindfulness that is inversely related to the internally distracted/ruminative state of the individual, which is exacerbated in depression^54,76,77. Mean breathing time and consistency data were extracted on this rapid assessment at each EMA. Across all participants’ data, we confirmed that consistency on this task was positively correlated to heart rate variability (HRV, Spearman’s r = 0.11, p = 0.002) that is a known marker for stress^78,79; specifically, inconsistency of performance on the stress assessment was related to lower HRV, indicative of greater stress.

At each EMA participants reported on their consumption of sugars, fats, and caffeine in the last 4 h. While diet monitoring itself can be quite sophisticated and burdensome with both subjective reports and objective tracking methodologies^80,81, we opted for a rapid non-burdensome assessment to ensure completion over 30 days. Specifically, within the context of depression, excessive consumption of processed fats and sugars has been related to the severity of symptoms, and intervention to change such diet patterns has shown success^13–16. Hence, based on a standard assessment of dietary fats and sugars⁸², we asked the following questions 4× per day, completed on a 0–6 item scale:

How many of these items have you had in the last 4 h? Red meat burger/sandwich; sausage/salami/bacon; whole egg; white bread; pizza; cheese; french fries; chips; butter popcorn; whole milk/milkshake; and fast food take-out.

How many of these items have you had in the last 4 h? Cake/cookies; ice-cream; chocolate; candy; pancakes/french toast; jam/honey; soda; juice or other sweetened beverage; and cereal with added sugar.

How many servings of caffeine (coffee/tea/energy drink) have you had in the last 4 h?