Association Between Cigarette Smoking and Anxiety Disorders During Adolescence and Early Adulthood FREE

Previous research has demonstrated that cigarette smoking is associated with psychiatric disorders among adolescents and adults in the general population.^1- 4 Although research has indicated that a positive association exists between cigarette smoking and some anxiety disorders,^4- 6 currently, relatively little is known about the factors underlying this association.

Two types of hypotheses have been advanced to account for the association between cigarette smoking and anxiety disorders. One hypothesis is that anxious individuals are at elevated risk for smoking initiation due to factors such as peer pressure,⁷ facilitation of social interaction,⁸ and the presumed calming effects of smoking.⁹ Research findings supporting this hypothesis have indicated that adolescents with symptoms of anxiety or depression were at higher risk for smoking initiation than asymptomatic adolescents,⁷ that adolescents and young adults with social fears had an increased risk of onset of nicotine dependence,⁸ and that smoking in the presence of a distracting stimulus was associated with reduced anxiety.⁹

Another hypothesis is that cigarette smoking contributes to the development of anxiety disorders¹⁰ due to factors including impaired respiration¹¹ and the presumed anxiogenic effects of nicotine.^12- 13 In support of this hypothesis, clinical studies have indicated that cigarette smoking preceded the onset of panic attacks among patients with panic disorder.^4,10 In addition, Breslau and Klein¹¹ have reported findings of a longitudinal epidemiological investigation indicating that daily smoking, as well as pulmonary complaints, were associated with the development of panic disorder among young adults. West and Hajek¹³ have reported that cessation of cigarette smoking was associated with a decline in anxiety over a 4-week period of smoking abstinence.

Prospective epidemiologic research can investigate both types of hypotheses by investigating whether anxiety disorders predict risk for future cigarette smoking and/or whether chronic smoking is associated with risk for subsequent anxiety disorders.¹¹ Because both cigarette smoking and anxiety disorders become prevalent during adolescence and early adulthood, it is important to investigate the association between anxiety disorders and cigarette smoking during adolescence and early adulthood in a large community-based sample. We report such longitudinal findings from the Children in the Community Study.^14- 15

Six hundred eighty-eight youths (51% female) were interviewed in their homes. Participants' mean (SD) age in 1983 was 14 (3) years, in 1985-1986 was 16 (3) years, and in 1991-1993 was 22 (3) years.^14- 15 The participating families were a subset of 976 families, randomly sampled on the basis of residence in upstate New York, with whom maternal interviews had been conducted in 1975 when the mean (SD) age of the youths was 5 (3) years. Written informed consent was obtained from participants at each assessment after study procedures were fully explained. The study procedures were approved by the New York State Psychiatric Institute's institutional review board.

The families in this study generally represented families in the northeastern United States in socioeconomic status and most demographic variables, but they reflected the sampled region with high proportions of those taking the 1983 survey being Catholic (54%) and white (91%).¹⁴ Participating families did not differ from the remainder of the original sample with regard to offspring temperament or maternal psychopathology, although paternal substance abuse in 1975 was less prevalent than in the remainder of the original sample.

Child psychiatric disorders and cigarette smoking were assessed in the 1983 and the 1985 through 1986 surveys by parental and offspring interviews using the Diagnostic Interview Schedule for Children,¹⁶ and in the 1991 through 1993 survey through offspring interviews using a modified and age-appropriate version of the Diagnostic Interview Schedule for Children. Parental psychopathology was assessed with the Disorganizing Poverty Interview¹⁵ and with items adapted from The New York High Risk Study Family Interview.¹⁷ Offspring childhood temperament was assessed in 1975 with the Disorganizing Poverty Interview. The respondents were interviewed separately by extensively trained and supervised lay interviewers who were blind to the responses of the other informant. Additional information on methods used is available elsewhere.^14- 15

Analyses of contingency tables were conducted to investigate bivariate associations between adolescent smoking and anxiety disorders, assessed when the mean age was 16 years, and early adulthood smoking and anxiety disorders, assessed when the mean age was 22 years. Complete data sets were available for all 688 participants. A power analysis indicated that there was sufficient statistical power to detect an association with a modest effect size. Nevertheless, because there were few cases with some specific anxiety disorders, these statistical analyses were repeated using an index of threshold or subthreshold anxiety disorders. For an individual to be diagnosed with a subthreshold anxiety disorder, the number of symptoms of that anxiety disorder was required to be at least 2 SDs above the sample mean. Inclusion of subthreshold anxiety disorders increased the prevalence of threshold or subthreshold anxiety disorders by 143% when the mean age was 16 years and by 48% when the mean age was 22 years. The results of the statistical analyses were not affected by the inclusion of subthreshold cases. Therefore, the analyses reported herein were conducted using the standard threshold anxiety disorder diagnoses.

Logistic regression analyses were conducted to investigate whether these associations remained significant after controlling simultaneously for age; sex; difficult childhood temperament; alcohol and/or drug use and anxiety and depressive disorders during adolescence; and parental smoking, education, andpsychopathology. Statistical analyses were conducted to investigate associations between anxiety disorders and heavy cigarette smoking, defined as smoking at least 20 cigarettes per day. Additional analyses were conducted to investigate associations between anxiety disorders and daily but less frequent cigarette smoking, defined as smoking 1 to 19 cigarettes per day.

At mean age 16 years, 39 adolescents (6%) smoked at least 20 cigarettes per day, and 44 (6%) had anxiety disorders. At mean age 22 years, 104 young adults (15%) smoked at least 20 cigarettes per day, and 68 (10%) had anxiety disorders. Twenty-two participants (3%) smoked at least 20 cigarettes per day during both adolescence and early adulthood. The other 17 participants (2%) who smoked at least 20 cigarettes per day during adolescence continued to smoke cigarettes at least occasionally during early adulthood. Fourteen adolescents (2%) had anxiety disorders during adolescence and early adulthood.¹⁸ Maternal and offspring reports of daily cigarette smoking during adolescence were significantly correlated (r = 0.71; P<.0001).

Anxiety disorders during adolescence were not significantly associated with cigarette smoking during early adulthood. Six (14%) of the 44 adolescents with anxiety disorders and 98 (15%) of the 644 adolescents without anxiety disorders smoked at least 20 cigarettes per day during early adulthood (odds ratio [OR], 0.88; 95% confidence interval [CI], 0.36-2.14). Supplemental analyses indicated that anxiety disorders at mean age of 14 years were not significantly associated with the onset of cigarette smoking during adolescence or early adulthood.

After controlling for covariates, adolescents who smoked 20 cigarettes or more per day were at elevated risk for agoraphobia, generalized anxiety disorder (GAD), or panic disorder during early adulthood (Table 1). Furthermore, the quantity and frequency of cigarette smoking during adolescence was also associated with risk for agoraphobia (adjusted OR, 1.47; 95% CI, 1.06-2.02), GAD (adjusted OR, 1.36; 95% CI, 1.07-1.71), and panic disorder (adjusted OR, 1.65; 95% CI, 1.05-2.62) during early adulthood. Chronic smoking during adolescence was significantly more strongly associated with agoraphobia, GAD, and panic disorder than with obsessive-compulsive disorder and social anxiety disorder, for which no increased risk was observed.

Overall, 12 (31%) of the 39 adolescents who smoked at least 20 cigarettes per day had anxiety disorders during early adulthood. In comparison, 56 (9%) of the 649 adolescents who were not chronic smokers had anxiety disorders during early adulthood. There were 69 participants who smoked every day and had an anxiety disorder during adolescence and/or early adulthood. Of these, 29 (42%) began smoking before they were diagnosed with an anxiety disorder, and 13 (19%) were diagnosed with anxiety disorders before they reported daily smoking (χ²₂ = 6.61; P = .04).

After controlling for covariates, heavy smoking during both adolescence and early adulthood was associated with elevated risk for early adulthood GAD (adjusted OR, 3.28; 95% CI, 1.42-7.61) and panic disorder (adjusted OR, 7.55; 95% CI, 1.55-36.86). Adolescents who smoked less than 20 cigarettes per day were not at elevated risk for anxiety disorders during early adulthood after the covariates were controlled. Among the 475 youths who did not smoke cigarettes and who did not have anxiety disorders at mean age 14 years, heavy smoking at mean age 16 years was associated with risk for anxiety disorders during early adulthood (OR, 10.78; 95% CI, 1.48-78.55). Anxiety disorders at mean age 16 years did not predict heavy cigarette smoking during early adulthood in this subsample.

Statistically significant associations were obtained with the following covariates: age (r₆₈₇ = 0.17; P<.0001), female sex (OR, 3.51; 95% CI, 1.64-7.52), difficult childhood temperament (OR, 2.49; 95% CI, 1.09-5.65), alcohol or drug abuse during adolescence (OR, 9.95; 95% CI, 4.15-23.83), and depressive disorders during adolescence (OR, 4.07; 95% CI, 1.57-10.53) were significantly associated with heavy cigarette smoking during adolescence, and female sex (OR, 2.80; 95% CI, 1.61-4.87) and depressive disorders during adolescence (OR, 6.88; 95% CI, 3.25-14.58) were significantly associated with anxiety disorders during early adulthood.

Our review of the literature indicates that these are the first findings from a community-based longitudinal study to demonstrate that heavy cigarette smoking during adolescence is associated with increased risk for agoraphobia, GAD, and panic disorder during early adulthood. Our findings are consistent with research suggesting that cigarette smoking may increase risk for certain anxiety disorders.^5,10- 11 At the same time, our findings indicate that cigarette smoking may not be associated with risk for obsessive-compulsive disorder or social anxiety disorder. Of considerable interest, previous research has indicated that impaired respiration may be associated with agoraphobia,¹⁹ GAD,²⁰ and panic disorder,^19,21 but not with obsessive-compulsive disorder²² or social anxiety disorder.²⁰ It will be of interest for future research to investigate whether different mechanisms, including impaired respiration,^11,19- 21 and the potentially anxiogenic effects of sustained nicotine intake^12- 13 may underlie the associations between cigarette smoking and agoraphobia, GAD, and panic disorder. It will also be important to investigate possible biological or psychological vulnerability factors that may increase risk for both cigarette smoking and certain anxiety disorders.

Although some previous studies have suggested that some types of anxiety symptoms during adolescence may be associated with risk for initiation of cigarette smoking⁷ or nicotine dependence,⁸ our findings suggest that adolescents with anxiety disorders may not be at elevated risk for chronic smoking during early adulthood. Further research will be needed to investigate whether some types of anxiety disorders may increase risk for cigarette smoking under certain circumstances or in specific populations.

Our findings provide health care professionals with additional evidence regarding the harmful consequences of cigarette smoking. By providing adolescents with information indicating that cigarette smoking may increase risk for the onset of anxiety disorders, it may be possible to increase the effectiveness of interventions that are designed to persuade young people to stop smoking cigarettes and to avoid initiating cigarette use.