Bidirectionality of smoking and depression in adolescents: a systematic review

Abstract

ObjectiveRecently, there is an increase in evidence that both smoking and mental health are continuously increasing among adolescents. This systematic review elucidates the research on evidence of the direction of association and risk factors influencing this relationship between smoking and depression. We also highlight the recent studies on the effects of electronic cigarettes and the development of the association between depression and smoking. MethodA literature search was conducted on databases including PubMed, OVID Medline, EMBASE, and PsychInfo and in relevant neurology and psychiatry journals. Terms used for electronic searches included smoking, tobacco, cigarettes; depression; adolescent, youth; direction. The relevant information was then utilized to synthesize the association between smoking and depression among adolescent population. ResultsThe initial search of the databases yielded 2738 related articles. After screening and cross-referencing duplicate articles and articles published in languages other than English, studies on animals, social and lifestyle factors, mood disorders, and substance use were excluded. Of these, a total of 122 publications only focusing on smoking and depression in the adolescent population were selected to synthesize this qualitative systemic review. These include 110 original research articles, 8 meta-analysis and reviews, and 4 reports and websites. ConclusionThe relationship between smoking and depression in the literature does not reflect the causeeffect relationship. Whereas the evidence on the direction of the association may reflect futile study designs, confounding factors and/or use of indirect measure of depression and quantification of smoking. Future prospective randomized studies should be aimed at elucidating the causal association.

The Mediating Effect of Depression on the Relationship between Loneliness and Substance Use in Korean Adolescents

“…Mental health problems and substance use also affect each other [ 31 ], increasing the risk of co-occurrence, and the prognosis is worse for comorbidities [ 32 ]. Although there is still no consensus as to whether depression increases substance consumption or whether substance consumption increases depression, evidence that depression precedes substance consumption is stronger, and longitudinal studies have shown this [ 28 , 33 ]. In addition, while loneliness and depression have different definitions, low social skills and a negative impact on interpersonal relationships are common to both; they are not only closely related but often occur simultaneously [ 34 ].…”

Examining the independent roles of cannabis use and tobacco use in depression risk: a multivariable Mendelian randomisation study

“…Tobacco smoking and cannabis use are both prospectively associated with increased risk of depression in conventional observational studies [4][5][6][7][8][9][10]. These substances are commonly coused, a behaviour comprising 'concurrent use' (i.e., use of both products in a pre-defined time period, including 'sequential' use) and co-administration (i.e., used simultaneously via the same delivery method) [11], the latter of which is more common in European countries [12].…”

Associations of cannabis use, tobacco use and incident anxiety, mood, and psychotic disorders: a systematic review and meta-analysis

“…In 2019, approximately 1.14 billion adults globally had smoked tobacco regularly and an estimated 200 million people used cannabis in the last year. 1 Existing observational evidence demonstrates prospective associations between cannabis use, tobacco use and mental ill-health; including depression, [2][3][4][5][6][7][8][9][10][11][12] anxiety, [7][8][9][10][12][13][14][15][16] and psychosis. 10,[17][18][19][20][21][22][23][24][25][26] However, it remains unclear if the associations in question are causal or if they result from observational data biases (e.g., confounding, reverse causality).…”