Journal of Rural Community Psychology               Volume E7   Number 1   Spring 2004

 

The relationship between smoking and depression in

the rural Midwestern United States

 

Jason M. Wise, David Weidner, & Donald. W. Preussler

 

Center for Rural Psychology, Kaneville, IL

 

 

ABSTRACT

 

The purpose of this study was to determine if there is a relationship between smoking and depression in a rural population in the Midwestern United States.  Participants included 1,191 adults (age 18-65) assessed and treated by the Farm Resource Center (FRC) between 1995-2000.  For purposes of this study, demographic and assessment data collected by FRC was analyzed.  The participants included farmers, miners, and other rural individuals and families served by FRC.  A reliable depression scale was formed from the participants’ pre-treatment assessment symptom checklist responses.  In a case control design, smokers were found to score significantly higher on the depression scale than non-smokers.  Broken down by gender, it was found that the significant difference existed for females, but not for males.  The effect sizes of the differences in both analyses were small.  It was concluded that smoking is mildly related to depression in women.

 

INTRODUCTION

 

The dangers of depression and tobacco use affect the lives of countless individuals and their families.  Major Depressive Disorder has a lifetime risk rate of 10% to 25% for females and from 5% to 12% for males (American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders, 4th edition, text revision, 2000).  Not only are individuals affected, but family members and coworkers also suffer the consequences of this problem.  The symptoms of depression can lead to unproductivity and relational difficulties, which can result in loss of employment, divorce and even suicide.

 

Although there appears to be a relationship between depression and tobacco use in the general population, it is not clear whether tobacco use causes depression or that depression causes use.  Little evidence regarding the mechanisms that influence this association is currently available (Dierker, Avenevoli, Stolar & Merikangas, 2002), but there appears to be a bi-directional relationship between the two (D’Mello & Flanagan, 1996).

 

Hall, Ricardo, Reus and Sees (1993) show that whether conceptualized as a trait, symptom, or a diagnosable disorder, depression is over-represented among the tobacco using population.  Depressed users are not only less likely to be successful at quitting, but if they succeed, they also experience more withdrawal symptoms upon quitting.  This study also showed that depressed users are more likely to relapse to their previous behavior.

 

Tobacco use may include the use of cigarettes, chewing tobacco, snuff, pipes and cigars.  It is estimated that 72% of the American adult population have used cigarettes and about 29% report use within a given month (DSM-IV-TR, 2000).  Tobacco use is currently the leading cause of disease burden (loss of healthy life contributing mainly to non-communicable diseases and injuries) in America (Ezzati, Lopez, Rodgers, Hoorn and Murray, 2002).

 

Kinnunen and Nordstrom (2000) postulates that the relationship between tobacco use and depression may be related to the biological reinforcing effects of nicotine.  The author infers that depressed individuals may view tobacco as self-medication. Quattrocki, Baird and Yurgelun-Todd (2000) show that nicotine binds to nicotinic receptors in the brain, which augments various neurotransmitters, including dopamine, serotonin, norepinephrine, acetylcholine, gammaaminobutyric acid and glutamate to relieve the symptoms of depression.  In addition, nicotine inhibits monoamine oxidase, the enzyme responsible for breaking down the biogenic amine neurotransmitters norepinephrine, serotonin, and dopamine in the brain.  This may explain the higher success rates for smoking cessation when an antidepressant is used as an adjuvant to treatment.

 

A study of 205 psychiatric patients showed that patients who had never used tobacco have substantially lower rates of currently diagnosed major depressive disorder than those who had a history of tobacco use (Acton, Prochaska, Kaplan, Small & Hall, 2002).  Another study, based on a multiple logistic model, showed that current users had a 40% higher risk of severe depression than non-users (Tanskane, Viinamaeki, Koivumaa-Honkanen, Hintikka, Jaeaeskelaeinen & Lehtonen, 1999).

 

While there has been a great deal of research indicating the correlation between tobacco use and depression among various populations, few studies have considered geographic factors.  No articles were found specifically on the link between smoking and depression in adult rural populations.  The purpose of this study is to determine if there is a relationship between smoking and depression in the rural United States.

 

The Farm Resource Center

 

The data for this study was collected by the Farm Resource Center (FRC), a non-profit, non-partisan, non-sectarian corporation established in 1985 to serve farm families in need of mental health crisis.  Farmers, coal miners, and their families are assessed and treated based on a community intervention model.  Thousands of data points have been collected, including demographic information such as marital status, employment status, initial presenting problem, occupation, age, gender, and race.  FRC also prides itself in providing treatment that works.  Included in each client’s intervention plan are follow-up treatment, well-being assessments, and customer satisfaction ratings.  FRC is unique in its approach to assessment and treatment. 

Clients come to FRC from a variety of sources.  FRC utilizes referral networks in potential consumers’ communities.  Outreach Workers and volunteers from local environments are utilized in providing services for FRC.  Consumers are assessed on a variety of measures, including symptom checklists, risk for suicide or domestic violence, medical problems, overall well-being, pre-post GAF, and progress notes.  Each consumer is given a treatment plan with goals based on his or her needs.  As the treatment plan is implemented, each consumer is monitored closely to ensure that goals are met.  Cases are closed in a formal manner.  Referrals are provided throughout treatment, linking consumers to community resources.  Consumers of FRC’s services are linked to the services by a number of methods including but not limited to local referrals, a toll-free Crisis Intervention Response line, local outreach workers, volunteers, and community seminars.  The services FRC provides are comprehensive, including assessment, crisis intervention, referral, consultation, and educational services.  FRC’s unique method of data collection and number of cases collected to date (over 2,000) allow researchers to explore differences in trends in assessment data between different groups of consumers, thus identifying and meeting the needs of target populations.

 

METHOD

 

Participants

 

The participants for this study included individuals and families who received services from FRC between 1995-2000.  Only adult participants age 18-65 and were assessed pre-treatment were included as participants in this study.  The total number of participants who met these criteria was 1,191.

 

The median age of the participants in this study was 42.0, with the middle 50% ranging from 33.0-51.0.  Of the 1,191 participants, 56.3% (N = 670) were female, and 43.7% (N = 521) were male.  More than half (51.6%) of the participants reported being married (N = 614).  The next largest percentage of participants (22.2%) were divorced (N = 264), while 13.9% reported never being married (N = 166), 8.9% reported being separated (N = 106), and 3.4% were widowed (N = 41).

 

A majority (96.3%) of the sample was Caucasian (N = 1,147), with African-Americans comprising the next largest percentage of participants (2.2%, N = 26).  Two-thirds of the sample reported unemployment (N = 788).  The most reported presenting problems were personal / emotional (62.3%, N = 742) and financial (22.8%, N = 271) in nature. The remaining presenting problems (employment, family, health, marital) each comprised less than 5% of the sample.

 

This sample of participants is representative of individuals and families seeking and obtaining community services in a rural setting in the Midwestern United States.  The sample includes farmers, coal miners, family members of farmers and coal miners, and other members of the rural community.  All of FRC’s services are confidential and are provided at no cost to the participants.

 

Design

 

This case control study examined the relationship between smoking and depression.  Participants were not assigned to treatment or control conditions.  They were naturally assigned to the demographic characteristics and assessment characteristics they met.  There were no control groups in this study.  Every participant received FRC standard protocol treatment.  For purposes of this study, only demographic and assessment data were used.  This study is not aimed at measuring the effectiveness of treatment nor is it to examine which groups improve significantly with treatment.

 

Procedures

 

The participants received standard treatment in their natural setting.  Consumers are assessed by Outreach Workers on a variety of measures, including symptom checklists, risk for suicide or domestic violence, medical problems, overall well-being, pre-post GAF, and progress notes.  For purposes of this study, a “depression” scale was artificially derived from the FRC symptom checklist.  Symptoms of depression included fatigue, insomnia, poor appetite, depressed, bored, urge to cry, negative thoughts/attitude, lonely, suicidal thoughts, helplessness/hopelessness, inability to concentrate, decreased energy, inappropriate crying, over eating, under eating, lowered sex drive, decline in work effectiveness, and isolation/withdrawal from others.  Only status variables and assessment information were used for this study.

 

RESULTS

 

To determine whether there were differences between smokers and non-smokers on the depression scale, reliability analysis was first conducted on the depression scale.  Using Cronbach’s alpha, a value of 0.83 was computed as an estimate of internal consistency of the depression scale.  (The item “over eating” was dropped to increase reliability.)

 

To determine whether smokers and non-smokers differed on depression, an independent samples t-test was conducted.  Because a Kolmogorov-Smirnov test for normality revealed that depression scores in this sample were not normally distributed (K-S = .11, p < .001), a nonparametric test of median differences in depression as a function of smoker/non-smoker status was also conducted using a Mann-Whitney U test.  In addition, the homogeneity of variance assumption required when conducting t-tests was not found to be violated, Levene's F = 3.28, p = .07.  The samples being compared can be considered independent because participants belonged to either the "smoker" or "non-smoker" groups.  The measure for depression is the artificially derived depression scale of the FRC symptom checklist, which is scale-level.

 

The independent samples t-test revealed that, on average, depression scores for smokers (`x = 7.05, s = 4.19, n = 472) were significantly higher than depression scores for non-smokers (`x = 6.20, s = 3.91, n = 719), t(1,189) = -3.55, p < .001.  There is a 95% likelihood that the true difference between these two groups lies between -1.31 and -0.38.  Given that this confidence interval does not include "0," there appears to be a difference in depression levels between smokers and non-smokers.  The effect size for the result is small, r = .10.  The nonparametric test of median differences produced a similar result, z = -3.37, p = .001.

 

To determine whether smokers and non-smokers differed by gender on depression, two independent samples t-tests were conducted.  (Because a Kolmogorov-Smirnov test for normality revealed that depression scores in this sample were not normally distributed, as described above, two Mann-Whitney U tests were also conducted).  For females, the homogeneity of variance assumption required when conducting t-tests was found to be violated, Levene's F = 3.93 p < .05. 

 

The independent samples t-test revealed that, on average, depression scores for female smokers (`x = 7.30, s = 4.19, n = 281) were significantly higher than depression scores for female non-smokers (`x = 6.23, s = 3.79, n = 389), t(566.07) = -3.39, p = .001.  There is a 95% likelihood that the true difference between these two groups lies between -1.69 and -0.45.  Given that this confidence interval does not include "0," there appears to be a difference in depression levels between female smokers and non-smokers.  The effect size for the result is also small, r = .14.  The nonparametric test of median differences produced a similar result, z = -3.23, p = .001.

 

For males, the homogeneity of variance assumption required when conducting t-tests was not found to be violated, Levene's F = 0.26 p = .61.  The independent samples t-test revealed that, on average, depression scores for male smokers (`x = 6.69, s = 4.17, n = 191) was not significantly different than depression scores for male non-smokers (`x = 6.17, s = 4.05, n = 330), t(519) = -1.38, p = .17.  There is a 95% likelihood that the true difference between these two groups lies between -1.24 and 0.22.  Given that this confidence interval includes "0," there appears to be no difference in depression levels between male smokers and non-smokers.  The effect size for the result is very small, r = .06.  The nonparametric test of median differences produced a similar result, z = -1.38, p = .17.

 

DISCUSSION

 

The first finding of this study was the psychometric validation of the depression scale.  Overall reliability of symptoms that comprised the depression scale was found to be suitable for clinical use.  Using the depression scale, smoking was related to depression in the sample of participants from the rural Midwestern United States.  Depression scores were higher among rural smokers than among non-smokers.  This finding was consistent with the literature review that linked smoking and depression in the general population.    

           

The magnitude of the difference in depression scores between rural smokers and non-smokers was small, which suggests that smoking behavior may be one of many signs to look for when screening for depression.  Physicians who provide mental health screening and treatment for rural populations may especially benefit from finding out whether patients are smokers.  Likewise, the gender of the smoker appeared to be an important factor in this study.  The significance of the comparison between smoking and depression was accounted for by gender.  Female smokers scored significantly higher on the depression scale compared to female non-smokers.  The differences in depression among male smokers and non-smokers were not significant.

           

Possible limits to this study include instrumentation and sample characteristics.  The test instrument is considered fairly reliable to make accurate clinical decisions, although the comprehensiveness of the instrument could be improved upon.  In addition, although this study included a large number of rural participants, not all geographic regions and ethnicities are represented.  Further research can aim to replicate this study, with a more comprehensive test instrument.  Other geographic regions may be targeted by other researchers.  Studies of the relationship between smoking and depression in rural minorities would be of interest.

 

REFERENCES

 

Acton, G. S., Prochaska, J. J.,  Kaplan, Aaron S., Small, T., & Hall, S. M.  (2001). 

            Depression and stages of change for smoking in psychiatric outpatients.

            Addictive Behaviors, 26(5), 621-631.

 

American Psychiatric Association:  Diagnostic and statistical manual of mental disorders,

            Fourth Edition, Text Revision. Washington, DC, American Psychiatric Association, 2000.

 

Dierker, L. C., Avenevoli, S., Stolar, M., & Merikangas, K. R.  (2002).  Smoking and depression:

            An examination of mechanisms of comorbidity. American Journal of Psychiatry, 159(6), 947-953.

 

D'Mello, D. A., & Flanagan, C.  (1996).  Seasons and depression: The influence of cigarette

            smoking. Addictive Behaviors, 21(5), 671-674.

 

Ezzati, M., Lopez, A.D., Rodgers, A., Hoorn, S.V., & Murray, C.J.L.  (2002).  Selected major

            risk factors and global and regional burden of disease.  The Lancet, 360(9343), 1357-1362.

 

Hall, S. M., Munoz, R. F., Reus, V. I., & Sees, K. L. (1993).  Nicotine, negative affect, and depression. 

            Journal of Consulting & Clinical Psychology, 61(5), 761-767.

 

Kinnunen, T., & Nordstrom, B. L. (2000). Smoking cessation for individuals with depression:

            Recommendations for treatment. In K.J. Palmer (Ed.), Smoking cessation. (pp. 35-48).

            Hong Kong: Adis International.

 

Quattrocki, E., Baird, A., & Yurgelun-Todd, D. (2000).  Biological aspects of the link between

            smoking and depression. Harvard Review of Psychiatry, 8(3), 99-110.

 

Tanskanen, A., Viinamaeki, H. Koivumaa-Honkanen, H. T., Hintikka, J., Jaeaeskelaeinen, J., &

            Lehtonen, J. (1999).  Smoking and depression among psychiatric patients. Nordic

             Journal of Psychiatry, 53(1), 45-48.