Results of this retrospective chart review demonstrate that the overall smoking cessation rate for patients with mental illness and/or substance abuse/dependence treated in a naturalistic setting are similar to those of published reports for controlled treatment in more general populations of smokers.15,20,46,47
For specific diagnoses associated with treatment responsiveness, our data demonstrate that the absence of an alcohol dependence history predicts better response to treatment, while the presence of schizophrenia/schizoaffective disorder predicts poorer outcome to treatment. The presence of marijuana abuse predicts better response to treatment.
A history of alcohol dependence might lead to lower quit rates than the absence of this history for several reasons. There is considerable evidence that chronic alcohol use leads to structural, physiological and functional brain changes,48-50
along with neuropsychological impairment.51
Chronic alcohol use leads to atrophy of the frontal lobes,48
hypofrontal brain metabolism52
and electrophysiological abnormalities.53
Such frontal lobe damage is associated with impulsivity, impaired planning, poor problem solving, and impaired insight and judgment.54
This type of brain damage (even in a subtle form) could account for the lower quit rates in smokers with a history of alcohol dependence, since behavioral modification (part of the treatment program here) might be more challenging in an impulsive subject with impaired coping and planning skills.
Cognitive deficits associated with alcohol dependence are well documented. It has been shown that between one-half and two-thirds of newly abstinent alcoholics exhibit cognitive impairment in the first few months of sobriety.51
These deficits may persist for years or indefinitely after detoxification in some patients, and include impairment in new learning, executive functioning, visual spatial abilities, and perceptual-motor integration.55
Specifically, verbal learning56,57
as well as abstract reasoning59,59-61
have been shown to be impaired in patients with a history of alcoholism. These specific deficits may lead to suboptimal participation in treatment, where verbally acquired directions for treatment and abstract reasoning are important for such components of treatment as medication instructions, suggestions for behavioral modification from group therapy, training in coping with stress, and in the identification of triggers.
Our data also support prior work31
which points to Schizophrenia and Schizoaffective disorders as illnesses that are particularly resistant to smoking cessation treatment. A central feature of these illnesses may be negative symptoms, such as avolition, alogia, and blunted affect.38
Also, similar to alcohol abuse/dependence, structural, physiological and functional deficits are seen in the schizophrenic brain, such as lower frontal lobe volume62
and frontal electrophysiological abnormalities.63
As noted above, structural and functional impairments of the frontal lobes are associated with impulsivity, poor planning and limited problem solving. Additionally, schizophrenic subjects have been identified as having moderately impaired executive functioning and more severely impaired verbal learning and memory when compared with controls.64
Consistent with the functional consequences for such cognitive dysfunction, one study demonstrated that the presence of prefrontal executive function deficits in spatial workingf memory and Wisconsin Card Sorting Test performance, prior to a quit attempt, was associated with smoking cessation treatment failure in smokers with schizophrenia, but not controls.65
They also have low Global Assessment of Functioning scores,66
a measure that includes social functioning, and a higher level of social support has been shown to be a positive predictor for smoking cessation.67
Taken together, these features (negative symptoms, frontal lobe dysfunction, and low global functioning scores) all point to potential mediating factors in the poor response people with Schizophrenia/Schizoaffective Disorder show to comprehensive treatment.
In this study, a history of Marijuana Abuse/Dependence was associated with slightly higher tobacco abstinence rates, when compared to other substance abuse and mental illness diagnoses. Many of the subjects were currently in treatment or had a history of treatment for substance abuse/dependence. Having a history of successful abstinence from a drug of abuse that was experienced through smoking (rather than intravenous or intranasal use) may have conferred a slight advantage in this group of tobacco users. Since they had been able to discontinue smoking marijuana in the past, perhaps this led to successful discontinuance of tobacco use due to higher confidence in their own abilities to overcome a similar habit.
One limitation of this study stems from the sample of male veteran subjects. It is known that the rates of substance abuse68,69
and affective disorders68
are higher in the veteran population when compared with similar gender and age-matched patients in the private sector. Furthermore, male veterans with severe mental illnesses, such as schizophrenia, tend to be older and to have had more inpatient hospitalizations,70
which suggests that the sample used in this study may have been older and more ill than patients who might be found in other types of healthcare systems. A second limitation of the study is that long-term follow up data (6 months to 1 year) was not available. A third limitation of the study is its retrospective design. The retrospective set-up of the study was the most reasonable and practical design for a naturalistic investigation of the data. While we are aware that such study designs may introduce incomplete study groups and interpretive bias during the chart review, these limitations were minimized by remaining cognizant of them.71,72
Another limitation of this study is the same as that of most naturalistic treatment studies, namely that subjects were not randomly assigned to treatments and clinicians were not blinded to the treatments administered. This lack of random assignment may have led to subjects being assigned to particular treatments which may have altered their possibility of quitting (e.g., it is likely that patients with Bipolar Disorder were less likely to receive bupropion HCl because mania is a potential side effect of this antidepressant). However, our data reflect treatment in a naturalistic setting, which may prove informative for real-life treatment scenarios.
In summary, this study identified several predictors of the success of smoking cessation in this naturalistic setting. While prior work has been done to start to tailor treatments to schizophrenic smokers,73
our data indicate that further research is needed to optimize treatments for smokers with psychotic illnesses and/or alcohol dependence. Both schizophrenic and alcohol dependent smokers may be better served with modified treatments15
that are specialized to take into account the needs of these specific populations.