Stress Sensitivity, Negative and Positive Affect, and Psychotic Experiences in Daily Life

EMA was used to assess stress sensitivity, negative and positive affect, psychotic experiences, and threat anticipation in daily life. For this, the same app was used as for the EMIcompass intervention (PsyMate), and assessments were completed at baseline, postintervention, and 4-week follow-up for 6 consecutive days, following the protocol from previous EMA studies [22,24,29,46,49]. Stress was operationalized as minor disturbances and distinctive unpleasant events, activities, and social situations that occur in the flow of daily life. Event-related stress was measured with an item asking participants to rate the most important event that had happened since the last beep on a 7-point Likert scale ranging from very unpleasant (rating of −3) to very pleasant (rating of 3) [54]. The item was recoded, such as higher ratings indicated higher levels of stress (with ratings of −3 coded as 7 and ratings of 3 coded as 1). Activity-related stress was measured by asking participants first to specify their current activity (eg, resting and watching TV), which was followed by asking them to rate the pleasantness of this activity on a 7-point Likert scale (1=very unpleasant; 7=very pleasant). Social stress was measured by asking participants to specify categorically with whom they were spending time (eg, nobody, partner, or family) and appraise the current social context using the items “I find being with these people pleasant” (reversed), “I feel accepted” (reversed), and “I feel excluded (if with someone)” or “I find it pleasant to be alone” (reversed) and “I would prefer to have company” (if alone) ranging from not at all (rating of 1) to very much (rating of 7). The good concurrent validity of these EMA stress measures has been reported [54,55]. Furthermore, a composite stress score was calculated using the mean score of all seven stress items [21,95]. Negative affect was assessed using five items asking participants to rate the extent to which they felt anxious, down, insecure, uncomfortable, and guilty at each entry point [54]. Positive affect was assessed by asking participants to rate the extent to which they felt cheerful and relaxed, all rated on a 7-point Likert scale ranging from not at all (rating of 1) to very much (rating of 7) [54,55,96]. Psychotic experiences were assessed using seven items (“I see things that aren’t really there,” “I hear things that aren’t really there,” “I feel suspicious/paranoid,” “I feel unreal,” “My thoughts are influenced by other,” “I can’t get these thoughts out of my head,” and “I feel like I am losing control”) rated on a 7-point Likert scale ranging from 1 (not at all) to 7 (very much) [55,96]. Threat anticipation was assessed by asking participants to think of what might happen in the next few hours and rate the item “I think that something unpleasant will happen” on a 7-point Likert scale (ranging from 1=not at all to 7=very much) [24,29]. Negative and positive affect, psychotic experiences, and threat anticipation scores were assessed by computing the mean scores. In line with earlier studies [22,24,29,46,49], items on stress, negative affect, and psychotic experiences were used as a proxy for individuals’ stress sensitivity in daily life by modeling the association between stress and (1) negative affect and (2) psychotic experiences. Thus, we conceptualized stress sensitivity in daily life as individuals’ affective and psychotic reactivity to minor daily stressors.