Abstract
Smartphones have become an essential part of modern life for many, offering constant access to communication, entertainment, social interaction, and information. Although smartphones may offer many advantages, problematic smartphone use (PSU), marked by a lack of control over usage and by continued engagement despite negative consequences, has been associated with adverse effects on sleep, psychological well-being, and everyday functioning. Growing evidence suggests that these effects may result from multiple interacting behavioral and biological pathways, including sleep and circadian rhythm disruption, reward-related reinforcement, cognitive and emotional arousal, and changes in stress-related physiological processes. Neuroimaging studies show that PSU is associated with changes in neural networks involved in reward processing, salience, and executive control; however, the relationship between smartphone exposure and pathological dopamine dysfunction remains unclear. Moreover, evidence for direct chronic activation of the sympathetic nervous system or for the development of systemic inflammation resulting from smartphone use remains limited, with current data more consistent with indirect pathways involving psychological stress, sleep disruption, autonomic regulation, and neuroendocrine signaling. Randomized trials demonstrated that changes in smartphone behavior can lead to improvements in clinically significant outcomes: interventions such as reducing total screen time, limiting smartphone use before bed, modifying notifications, cognitive-behavioral therapy, mindfulness-based approaches, and increasing physical activity have been found to reduce PSU and improve sleep, stress, mood, or well-being. This review examines the potential biological mechanisms by which PSU may adversely affect health and assesses practical interventions that could mitigate these effects.