Digital devices use LED lighting

Almost all digital devices are backlit with white light-emitting diodes (LEDs), a light source with a spectrum unlike all natural sources – sunlight, moonlight and starlight. ^{Reference Gaston, Visser and Hölker16} LEDs have a dominant spectral wavelength in the blue light range, suppressing melatonin, disrupting circadian function, increasing alertness and reducing sleep, including in adolescents. ^{Reference Bauer, Glenn, Monteith, Gottlieb, Ritter and Geddes17–Reference West, Jablonski, Warfield, Cecil, James and Ayers19} Evening online exposure to digital devices may negatively impact circadian physiology, alertness and cognitive performance. ^{Reference Chang, Aeschbach, Duffy and Czeisler20,Reference Cajochen, Frey, Anders, Späti, Bues and Pross21} When comparing light sources, the circadian effects from computer screens and other light-emitting devices is high and can be disruptive to sleep patterns. ^{Reference Gringras, Middleton, Skene and Revell22} The disruption of circadian rhythms by LED lighting and lifestyles may also impact pharmacotherapy dosing, efficacy and toxicity for a variety of conditions. ^{Reference Ayyar and Sukumaran23–Reference Dallmann, Okyar and Lévi25} Additionally, blue light exposure can damage retinal pigment epithelial cells. ^{Reference Baker, Putnam, Kozlowski, Anderson, Bird and Chmielewski26}

Psychological impairments from excessive internet use

There are many psychological characteristics associated with excessive internet use. Among US college students, excessive internet use is associated with depression, stress and boredom. ^{Reference Li, O’Brien, Snyder and Howard27} Loneliness and feelings of isolation may be associated with excessive internet use. ^{Reference Wang and Zeng28,Reference Saadati, Mirzaei, Okhovat and Khodamoradi29} Other characteristics reported in regard to excessive online use include preoccupation with the internet, irritability when unable to use the internet and depression and anxiety. ^{Reference O’Brien, Li, Snyder and Howard30} In adolescents, a major contributor to both excessive online use of social media and social media fatigue is fear of missing out. ^{Reference Dhir, Yossatorn, Kaur and Chen31,Reference Oberst, Wegmann, Stodt, Brand and Chamarro32} Social media may make adolescents feel socially connected and emotionally supported by peers, although around two out of three report exposure to hate-based content. ^{Reference Bickham, Hunt, Bediou and Rich33} While social media can offer a connection for marginalised youth, excessive social media use can result in sleep difficulties and negative mental health, including depression and anxiety. ^{34,Reference Alonzo, Hussain, Stranges and Anderson35} Adolescents who spend more than 3 h per day on social media are at increased risk of mental health problems. ^{Reference Riehm, Feder, Tormohlen, Crum, Young and Green36} Fear of being neglected by online peers may contribute to excessive use of social media. ^{Reference Fabris, Marengo, Longobardi and Settanni37} Heavy use of social media is associated with psychological distress and poor mental health outcomes in adolescents and young adults, disproportionately impacting females, with the younger more vulnerable. ^{Reference Alonzo, Hussain, Stranges and Anderson35,Reference Mougharbel, Chaput, Sampasa-Kanyinga, Colman, Leatherdale and Patte38–Reference Lin, Sidani, Shensa, Radovic, Miller and Colditz42} While females may overuse social media, both adolescent and adult males are more likely to overuse internet gaming. ^{Reference Ropovik, Martončik, Babinčák, Baník, Vargová and Adamkovič43–Reference Su, Han, Yu, Wu and Potenza45} Excessive online use can also interfere with completion of everyday activities. ^{Reference Jeong, Han, Kim and Jeong46} Recognising the potential negative impact, the Diagnostic and statistical manual of mental disorders 5th edition text revision recognises internet gaming disorder as a condition for further study. ⁴⁷ Additionally, patients who overuse the internet may experience withdrawal symptoms when unable to go online, such as restlessness and irritability. ^{Reference Li, O’Brien, Snyder and Howard27} As psychiatrists interact with patients, it is therefore important to be cognizant of internet and social media use, especially in young, at-risk populations.

Limitations

There are many limitations to this discussion. Specific definitions of excessive online use, and potential measures to correct excessive online behaviour, are not included. Many individual characteristics that may impact online use are not discussed. Multiple negative consequences of pathologic internet use are not discussed, including harmful impacts on family relationships, neglect of social activities, cyberbullying and poor academic or work performance. International factors associated with internet sites and social media use are not discussed. The validity of online content, including social media, ethical issues and risks associated with cybercrime, are not included. The implications of exposure to internet pornography, including in children and adolescents, are not included. The impacts of online exposure on developing brains in infancy and childhood are beyond the scope of this discussion.

In conclusion, in our digital world, a fundamental understanding of patients’ online behaviour is needed. Excessive internet activities may impact both physiological and mental health, and also diagnosis and treatment. Psychiatrists should routinely question patients about their online activities, and suggest changes when medically indicated.