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- Treatment of Drug-Dependent Individuals With Comorbid Mental Disorders
Treatment of Drug-Dependent Individuals With Comorbid Mental Disorders
- By N.I. D.A.
- Published 01/15/2007
- Dual Diagnosis
- Unrated
Alexander H. Glassman
Comorbidity is the existence of two conditions in the same individual at a greater frequency than would be expected by chance alone. The existence of such associations says nothing about the underlying cause of the comorbidity.
Cigarette smoking in the United States has long been associated with an increased level of psychiatric symptomatology, but until recently this was not thought of in terms of specific diagnostic entities. Cigarette smokers were simply thought more likely to be "nervous" people than nonsmokers (Glassman 1993).
However, it is important to realize that the appearance of comorbidity can be strongly influenced by social factors. If everybody smoked, there could be no association between smoking and any psychiatric condition.
In 1985, while testing a new drug for smoking cessation, Glassman and colleagues (1988) noted what they felt was an astounding lifetime rate of major depression among smokers coming to the clinic.
Forty two of 71 smokers (60 percent) had a history of major depression, while the best available data suggest lifetime rates for the general community of around 18 percent (Kessler et al. 1994).
This threefold increase in the observed rate of major depression was even more dramatic than it might first appear because smokers coming to the clinic were screened to exclude individuals who were presently ill.
Whereas community epidemiological data represent both individuals presently ill and those with only a past history of major depression, the clinic sample consisted only of smokers with a past history of depression. In retrospect, it is likely that the extraordinarily high rate of prior major depression observed by the researchers was an artifact of the particular academic population that they had happened to study.
The vast majority of the 71 smokers who participated in the study were either postdoctoral students or faculty at Columbia University, and most came from the medical school campus. This finding was undoubtedly related to the exceptionally high rate of major depression observed. Medical school faculty and their graduate students face considerably more social pressure to give up smoking than the general population.
It would seem reasonable to assume that in groups where awareness of the health risks increases and social pressure to stop smoking grows, those who can quit easily do so and those who remain smokers are individuals more vulnerable to nicotine.
Hughes and associates (1986) had earlier shown that patients coming to a medical center for treatment of a variety of psychiatric conditions, including depression, were more likely to be smokers than the general population.
That seemed intuitively reasonable. However, once the strength of the association with a specific history of depression became apparent, it seemed worthwhile to determine whether a history of major depression influenced smoking cessation—and it did.
Again, that patients presently depressed have more difficulty quitting than individuals not depressed seems obvious; however, the finding that a history of depression would still be associated with cessation failure, even when an individual had been euthymic for a considerable period of time, was not so obvious and required replication.
The first two replications both came from previously existing data sets. The St. Louis node of the Epidemiological Catchment Area (ECA) study contained both psychiatric diagnostic information and smoking history on over 3,200 randomly selected community residents (Glassman et al. 1990).
Among those individuals with either no psychiatric illness or any psychiatric illness except major depression, 47 percent of the women and 68 percent of the men had at some time in their lives been regular smokers.
By comparison, among those individuals with a history of major depression, 65 percent of the women and 80 percent of the men had been regular smokers. The increases among both men and women are highly significant, but the increased rate among the depressed women is particularly striking.
The data on cessation also very much paralleled the data for the original small clinical sample. Thirty-one percent of those smokers with no history of any psychiatric history were able to stop smoking for more than 1 year, and 28 percent of those individuals with either no psychiatric history or no psychiatric history except major depression were able to quit.
Among those with a lifetime history of major depression, less than 14 percent of smokers were able to stop and remain abstinent. Similarly, data on 3,023 individuals from the National Health and Nutrition Examination Survey (N-HANES) also demonstrated an increased rate of smoking and a decreased rate of quitting associated with increasing levels of depression (Anda et al. 1990).
The major difference between the ECA and the N-HANES data sets is that the ECA instruments classified individuals by diagnosis, while N-HANES obtained only symptomatic measures of depression. A subsequent community survey also produced by the Centers for Disease Control and
Prevention was the Hispanic NHANES, which studied 3,337 individuals of Mexican origin and obtained both symptomatic and diagnostic measures of depression on this sample (R.F. Anda, personal communication, January 11, 1995). It is important to understand that this is an epidemiology survey that records lifetime rates of illness, and lifetime major depression involves both cases that are presently ill and cases of past illness.
Presently ill cases will always show symptoms of depression as well as meeting diagnostic criteria. However, cases of past history may or may not presently have symptoms of depression.
Both those individuals with symptoms but no diagnosis and those with a diagnosis but no symptoms showed higher rates of smoking than individuals with neither condition. However, individuals with both a diagnosis and symptoms of major depression showed the highest rates of smoking.
Thus, there is now evidence that symptoms, as well as a diagnosis of major depression, are associated with cigarette smoking. These data are somewhat more complex than is readily apparent. It might seem that symptoms of depression and major depression alone are approximately equal in their likelihood of being associated with cigarette smoking. However, it is probable that the cases of major depression in the major depression-only group will be less severe and less likely to be recurrent than those cases in the group with both major depression and present symptoms of depression.
Recurrent major depression has regularly been shown to have higher levels of interepisode depressive symptomatology (Keller et al. 1983; Dalack et al. 1995) than single episode cases. Thus, it seems probable that the major depression-only group will contain a greater proportion of single episode cases of major depression.
Cases of single episodes of major depression have already been shown in both clinical (Glassman et al. 1993) and epidemiological (Covey et al. 1994) research to be less strongly associated than recurrent major depression with cigarette smoking.
As a result, it would seem likely that both individuals with symptoms of depression and individuals with a single episode of major depression are more likely to be smokers than individuals with no history of either condition. In addition, the association between smoking and depression will be strongest among those individuals with either recurrent major depression or major depression and high levels of chronic depressive symptoms.
There is also evidence that a similar step function exists with the intensity of smoking. At least among women, Kendler and associates (1993) have replicated the finding that heavier smoking is associated with an increasing likelihood of a lifetime history of major depression, and Breslau and associates (1993) have shown that this same association is greater in dependent than in nondependent smokers.
One of the issues not dealt with adequately in any of these three large data sets is the role of other psychiatric diagnoses. Breslau has examined 1,200 young adults (Breslau et al. 1991) and Kendler has data on 1,566 female twins (Kendler et al. 1993).
Breslau replicates the previously observed associations between major depression and both smoking and smoking cessation. Kendler does not examine cessation, but does find a strong association between smoking and a lifetime diagnosis of major depression. However, these studies provide information that earlier data sets were not designed to address.
As a major example, both Breslau and Kendler demonstrated that the relationship between major depression and smoking persists even after controlling for both alcohol and anxiety disorders.
Both also showed that the association was most robust among heavier or more dependent smokers.
~~~
Continued on source document:
NIDA Research Monograph, Number 172
Comorbidity is the existence of two conditions in the same individual at a greater frequency than would be expected by chance alone. The existence of such associations says nothing about the underlying cause of the comorbidity.
Cigarette smoking in the United States has long been associated with an increased level of psychiatric symptomatology, but until recently this was not thought of in terms of specific diagnostic entities. Cigarette smokers were simply thought more likely to be "nervous" people than nonsmokers (Glassman 1993).
However, it is important to realize that the appearance of comorbidity can be strongly influenced by social factors. If everybody smoked, there could be no association between smoking and any psychiatric condition.
In 1985, while testing a new drug for smoking cessation, Glassman and colleagues (1988) noted what they felt was an astounding lifetime rate of major depression among smokers coming to the clinic.
Forty two of 71 smokers (60 percent) had a history of major depression, while the best available data suggest lifetime rates for the general community of around 18 percent (Kessler et al. 1994).
This threefold increase in the observed rate of major depression was even more dramatic than it might first appear because smokers coming to the clinic were screened to exclude individuals who were presently ill.
Whereas community epidemiological data represent both individuals presently ill and those with only a past history of major depression, the clinic sample consisted only of smokers with a past history of depression. In retrospect, it is likely that the extraordinarily high rate of prior major depression observed by the researchers was an artifact of the particular academic population that they had happened to study.
The vast majority of the 71 smokers who participated in the study were either postdoctoral students or faculty at Columbia University, and most came from the medical school campus. This finding was undoubtedly related to the exceptionally high rate of major depression observed. Medical school faculty and their graduate students face considerably more social pressure to give up smoking than the general population.
It would seem reasonable to assume that in groups where awareness of the health risks increases and social pressure to stop smoking grows, those who can quit easily do so and those who remain smokers are individuals more vulnerable to nicotine.
Hughes and associates (1986) had earlier shown that patients coming to a medical center for treatment of a variety of psychiatric conditions, including depression, were more likely to be smokers than the general population.
That seemed intuitively reasonable. However, once the strength of the association with a specific history of depression became apparent, it seemed worthwhile to determine whether a history of major depression influenced smoking cessation—and it did.
Again, that patients presently depressed have more difficulty quitting than individuals not depressed seems obvious; however, the finding that a history of depression would still be associated with cessation failure, even when an individual had been euthymic for a considerable period of time, was not so obvious and required replication.
The first two replications both came from previously existing data sets. The St. Louis node of the Epidemiological Catchment Area (ECA) study contained both psychiatric diagnostic information and smoking history on over 3,200 randomly selected community residents (Glassman et al. 1990).
Among those individuals with either no psychiatric illness or any psychiatric illness except major depression, 47 percent of the women and 68 percent of the men had at some time in their lives been regular smokers.
By comparison, among those individuals with a history of major depression, 65 percent of the women and 80 percent of the men had been regular smokers. The increases among both men and women are highly significant, but the increased rate among the depressed women is particularly striking.
The data on cessation also very much paralleled the data for the original small clinical sample. Thirty-one percent of those smokers with no history of any psychiatric history were able to stop smoking for more than 1 year, and 28 percent of those individuals with either no psychiatric history or no psychiatric history except major depression were able to quit.
Among those with a lifetime history of major depression, less than 14 percent of smokers were able to stop and remain abstinent. Similarly, data on 3,023 individuals from the National Health and Nutrition Examination Survey (N-HANES) also demonstrated an increased rate of smoking and a decreased rate of quitting associated with increasing levels of depression (Anda et al. 1990).
The major difference between the ECA and the N-HANES data sets is that the ECA instruments classified individuals by diagnosis, while N-HANES obtained only symptomatic measures of depression. A subsequent community survey also produced by the Centers for Disease Control and
Prevention was the Hispanic NHANES, which studied 3,337 individuals of Mexican origin and obtained both symptomatic and diagnostic measures of depression on this sample (R.F. Anda, personal communication, January 11, 1995). It is important to understand that this is an epidemiology survey that records lifetime rates of illness, and lifetime major depression involves both cases that are presently ill and cases of past illness.
Presently ill cases will always show symptoms of depression as well as meeting diagnostic criteria. However, cases of past history may or may not presently have symptoms of depression.
Both those individuals with symptoms but no diagnosis and those with a diagnosis but no symptoms showed higher rates of smoking than individuals with neither condition. However, individuals with both a diagnosis and symptoms of major depression showed the highest rates of smoking.
Thus, there is now evidence that symptoms, as well as a diagnosis of major depression, are associated with cigarette smoking. These data are somewhat more complex than is readily apparent. It might seem that symptoms of depression and major depression alone are approximately equal in their likelihood of being associated with cigarette smoking. However, it is probable that the cases of major depression in the major depression-only group will be less severe and less likely to be recurrent than those cases in the group with both major depression and present symptoms of depression.
Recurrent major depression has regularly been shown to have higher levels of interepisode depressive symptomatology (Keller et al. 1983; Dalack et al. 1995) than single episode cases. Thus, it seems probable that the major depression-only group will contain a greater proportion of single episode cases of major depression.
Cases of single episodes of major depression have already been shown in both clinical (Glassman et al. 1993) and epidemiological (Covey et al. 1994) research to be less strongly associated than recurrent major depression with cigarette smoking.
As a result, it would seem likely that both individuals with symptoms of depression and individuals with a single episode of major depression are more likely to be smokers than individuals with no history of either condition. In addition, the association between smoking and depression will be strongest among those individuals with either recurrent major depression or major depression and high levels of chronic depressive symptoms.
There is also evidence that a similar step function exists with the intensity of smoking. At least among women, Kendler and associates (1993) have replicated the finding that heavier smoking is associated with an increasing likelihood of a lifetime history of major depression, and Breslau and associates (1993) have shown that this same association is greater in dependent than in nondependent smokers.
One of the issues not dealt with adequately in any of these three large data sets is the role of other psychiatric diagnoses. Breslau has examined 1,200 young adults (Breslau et al. 1991) and Kendler has data on 1,566 female twins (Kendler et al. 1993).
Breslau replicates the previously observed associations between major depression and both smoking and smoking cessation. Kendler does not examine cessation, but does find a strong association between smoking and a lifetime diagnosis of major depression. However, these studies provide information that earlier data sets were not designed to address.
As a major example, both Breslau and Kendler demonstrated that the relationship between major depression and smoking persists even after controlling for both alcohol and anxiety disorders.
Both also showed that the association was most robust among heavier or more dependent smokers.
~~~
Continued on source document:
NIDA Research Monograph, Number 172
