In this study, we compared several psychological characteristics of problematic smartphone users and normal users. The problematic smartphone usage group had higher scores for negative emotions, such as depression and anxiety, than the normal usage group. These findings are consistent with previous studies that reported a close association between problematic smartphone usage and emotional problems [40, 41]. The comparison of our subjects also suggested that problematic smartphone users had lower levels of mindfulness than the normal usage group, consistent with previous studies showing low levels of mindfulness in addictive diseases [42]. In this study, problematic smartphone users showed significant differences from the normal usage group in awareness and non-judgement among several sub-factors of mindfulness. In the context of mindfulness, awareness is the ability to notice what thoughts, feelings and sensations are currently going on inside oneself [43]. Loss of control over addictive behaviour is closely related to decreased awareness of interoceptive signals derived from addictive behaviour [44]. Our results suggest that a tendency to act without sufficient awareness may lead to a loss of control over excessive smartphone usage. On the other hand, a non-judgemental attitude has been negatively correlated with affective symptoms, such as depression and anxiety [45]. Thus, we speculate that low levels of non-judgement in problematic smartphone users may be associated with their high tendency toward emotional difficulties.
We also compared impulsiveness assessed through self-reports (BIS) and attentional capacity assessed through CATs between problematic and normal smartphone users. Problematic smartphone users reported a higher level of impulsivity than normal users, which is consistent with previous studies of impulsiveness in problematic smartphone users [46]. On the other hand, the CAT results showed no difference between the groups’ omission and commission errors of selective, sustained and divided attention. Despite the high correlation between ADHD and problematic smartphone use [47], a previous study reported that the adverse effects of smartphone use on attention are not remarkable in the general population [48]. A recent study also reported no impairment in the problematic smartphone use of cognitive tests evaluating executive function [49]. Another study reported that problematic smartphone users performed poorly on cognitive tests that assessed attentional control with interfering stimuli [50]. We did not conduct the Flanker test, which measures one’s ability to respond to target stimuli while ignoring interfering stimuli among the CAT items. Thus, although our study suggests that abnormalities in selective, sustained and divided attention are not prominent among problematic smartphone users, attentional control in the presence of distractions in this group requires further investigation.
Our CAT results appear to conflict somewhat with existing research: commission error, an inappropriate response to a nontarget, has been proposed as an indicator of impulsivity in cognitive tasks [51], but we found no correlation between CAT indicators and BIS scores. However, previous studies that measured impulsivity often report conflicting results between self-reports and cognitive tasks [52–54]. Impulsivity can be conceptualized and measured in many ways, and different cognitive tasks and self-report questionnaires measure different aspects of impulsivity. For example, three-dimensional constructs of impulsivity, including impulsive choice, behaviour and personality traits, have been proposed [55]. A cognitive task usually measures impulsive behaviour, whereas self-report lists measure impulsive personality traits. Our results suggest that although impulsive behaviour is not prominent in problematic smartphone users, impulsive personality traits are. These results are consistent with prior evidence that impulsive personality traits are linked to vulnerability to addictive disorders [56].
In this study, we investigated the relationship between mindfulness, impulsivity and addictive smartphone usage. Evidence has shown that impulsivity is associated with mindfulness [57, 58] and addictive behaviour [59, 60]. Consistent with previous studies, BIS scores showed significant correlations with FFMQ-SF, MAAS and SAPS scores in this study’s correlation analysis. We further explored whether impulsivity plays a mediating role between mindfulness and addictive smartphone usage and found that the acting with awareness facet of mindfulness affects addictive smartphone usage through attentional impulsivity, the impulsiveness revealed during tasks requiring attentional control [61]. As attentional control is a major domain of executive function [62], attentional impulsivity refers to impulsiveness during executive functioning. Disease models of addictive behaviour have identified diminished executive functioning as a major pathophysiological cause of loss of control over addictive behaviour [63]. Therefore, we speculate that diminished executive functioning reflected by high attentional impulsivity is linked to addictive patterns of smartphone use. Acting with awareness refers to the ability to pay attention to activities in the present moment [32, 64]. A sufficient level of awareness is a prerequisite for self-monitoring and self-regulation, which are key elements in performing higher cognitive functions, such as executive function [65]. Our mediation analysis results imply that diminished executive functioning, which is reflected in high attentional impulsivity, mediates the relationship between low levels of awareness and addictive smartphone usage. These findings are in line with a previous study showing that mindfulness acts as a protective factor in problematic smartphone use, but high impulsivity can interfere with it [13]. In addition, previous studies on mindfulness have revealed that mindfulness meditation and mindfulness-based psychological interventions can strengthen executive control by improving awareness [66]. Therefore, our current findings support that mindfulness-based interventions can improve addictive smartphone use patterns [14].
The limitations of this study are as follows. First, we did not evaluate objective smartphone usage patterns in the real world, only through the self-reported questionnaire scale. Given the diversity of smartphone-based online activities, collecting objective data on time consumption and behavioural patterns of online activities through smartphones would be helpful. Second, the measurement tools used to evaluate the main variables in this study were limited. Mindfulness, impulsivity and attention are all composed of various psychometric aspects, so a comprehensive evaluation is needed. Mindfulness can be defined and evaluated not only as a trait factor, as in this study, but also as a state factor during mindful attention [67]. Our study did not include impulsive choice tasks, which can be used to evaluate a person’s tendency to choose smaller, immediate rewards over larger, delayed rewards [21]. As previously mentioned, this study also did not include the Flanker test, which evaluates the capacity to maintain attention despite a distractor. Third, the number of subjects in this study was not large enough to sufficiently explore the relationship between variables. For example, structural equation modelling, which has the advantage of providing a flexible framework for analysing complex relationships between multiple variables, usually requires 200 or more subjects [68]. Fourth, this study’s cross-sectional design limited our ability to evaluate the causal relationship between mindfulness and problematic smartphone usage. A longitudinal follow-up study is needed to explore changes in addictive smartphone usage according to changes in mindfulness levels.
In conclusion, this study evaluated the levels of mindfulness, impulsiveness and attentional control of problematic smartphone users and explored the relationships among the variables. Problematic smartphone users had a lower level of mindfulness than healthy users, and the difference was particularly noticeable in the acting with awareness and non-judgement facets of mindfulness. The problematic smartphone usage group had higher impulsivity than the normal usage group, but there was no difference in their performance on-attention tasks. In particular, our results suggest that a low level of awareness has a significant effect on addictive patterns of smartphone use and that diminished executive control, reflected by high attentional impulsivity, mediates the relationship between awareness and addictive smartphone usage. The results of this study imply that mindfulness-based interventions can be an effective approach to problematic smartphone usage.