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Regularly having feelings of depression was assessed by the questions, “How often do you feel depressed? Would you say daily, weekly, monthly, a few times a year, or never?” and “Thinking about the last time you felt depressed, how would you describe the level of these feelings? Would you say a little, a lot, or somewhere in between?” Respondents indicating 1) feeling depressed daily and describing the level of those feelings as “somewhere in between a little and a lot” or “a lot” or 2) feeling depressed weekly and describing the level of those feelings as “a lot” were considered as regularly having feelings of depression. Those who answered 1) “never” feeling depressed and who did not answer the question on the level of the feelings, 2) feeling depressed daily and described the level of those feelings as “a little,” 3) feeling depressed weekly and described the level of those feelings as “a little” or “somewhere in between a little and a lot,” or 4) feeling depressed “monthly” or “a few times a year” and described the level of those feelings as “a little,” “a lot” or “somewhere in between a little and a lot” were considered as not having feelings of depression. Others not falling within those combinations were excluded.
* Any tobacco use was defined as use either “every day” or “some days” of at least one tobacco product among individuals (for cigarettes, users were defined as persons who reported use either “every day” or “some days” and had smoked ≥100 cigarettes during their lifetime).
** Any combustible tobacco use was defined as use either “every day” or “some days” of at least one combustible tobacco product: cigarettes; cigars, cigarillos, filtered little cigars; pipes, water pipes, or hookah (for cigarettes, users were defined as persons who reported use either “every day” or “some days” and had smoked ≥100 cigarette during their lifetime).
*** Current cigarette smokers were defined as persons who reported smoking ≥100 cigarettes during their lifetime and now smoked cigarettes “every day” or “some days.”
**** Reported smoking cigars, cigarillos, or little filtered cigars at least once during their lifetime and now smoked at least one of these products “every day” or “some days.”
^ Reported smoking tobacco in a regular pipe, water pipe, or hookah at least once during their lifetime and now smoked at least one of these products “every day” or “some days.”
^^ Reported using electronic cigarettes at least once during their lifetime and now used e-cigarettes “every day” or “some days.”
^^^ Reported using chewing tobacco, snuff, dip, snus, or dissolvable tobacco at least once during their lifetime and now used at least one of these products “every day” or “some days.
^^^^Current multiple tobacco product users were defined as adults who reported use “every day” or “some days” for at least two or more of the following tobacco products: cigarettes (≥100 cigarettes during lifetime); cigars, cigarillos, filtered little cigars; pipes, water pipes, or hookah; e-cigarettes; or smokeless tobacco products.