Schizophrenia and smoking
Encyclopedia
Studies across 20 countries show a strong association between schizophrenia
and smoking
. For example, in the United States
, 80% or more of schizophrenics smoke, compared to 20% of the general population in 2006.
Though it is well established that smoking is more prevalent among schizophrenics than the general population as well as those with other psychiatric diagnoses, there is currently no definitive explanation for this difference. Many social, psychological, and biological explanations have been proposed, but today research focuses on neurobiology.
Increased rates of smoking among schizophrenics has a number of serious impacts, including increased rates of mortality
, increased risk of cardiovascular disease
, reduced treatment effectiveness, and greater financial hardship. Studies have also shown that in a male population, having a schizophrenia spectrum disorder puts a patient at risk of excess tobacco use. As a result, researchers believe it is important for mental health professionals to combat smoking among schizophrenics.
. The psychoanalytic hypothesis argued that schizophrenics suffer from an oral fixation, resulting in excessive preoccupation with oral gratification.
The socioeconomic/environmental hypothesis proposed that smoking results because many schizophrenics are unemployed and inactive, so smoking relieves boredom. Research has found that this explanation alone cannot account for the extreme amount of smoking among schizophrenics.
The personality hypothesis focused on the association between smoking and higher level of neuroticism and anxiety. This hypothesis proposed that anxiety as a symptom of schizophrenia may contribute to smoking.
The psychological tool hypothesis argues that smokers use nicotine to manipulate their mental state in response to various environmental conditions, such as reducing stress and managing negative emotions. Research on this hypothesis notes that schizophrenics often have poor coping skills, so use of smoking as psychological tool may result in a vicious cycle of more and more smoking.
The self-medication hypothesis argues that schizophrenics use nicotine to compensate for the cognitive deficits that result from schizophrenia, antipsychotic medication used to treat schizophrenia, or both.
The cognitive effects hypothesis suggests that nicotine has positive effects on cognition, so smoking is used to improve neurocognitive
dysfunction.
In these hypotheses, one factor often implicated is the effects of institutionalization and boredom. However, schizophrenics smoke at higher rates and for longer periods than other groups that experience both institutionalization and boredom.
Another factor often implicated is to the side effects
of antipsychotic medications. Atypical antipsychotics may work against smoking cessation
, as symptoms of smoking cessation such as irritable mood, mental dulling, and increased appetite overlap with side effects of atypical antipsychotics. Some also argue that smoking works to reduce the side effects of antipsychotics. However, research shows no association between smoking and antipsychotic use after controlling for schizophrenia.
Another frequently implicated factor is increased mental acuity associated with smoking, important because of the mental dulling found over time in schizophrenia. However, both schizophrenics and the general population experience this effect, so it cannot fully explain increased smoking in schizophrenics.
Another major criticism is based on the finding that the association between smoking and schizophrenia is about as strong across all cultures. This finding implies that the association is not solely social or cultural, but rather has a strong biological component.
, particularly how negative symptoms such as social withdrawal and apathy may be caused by a deficiency on dopamine in the prefrontal cortex
while positive symptoms such as delusion
s and hallucination
s may be caused by excess dopamine in the mesolimbic pathway
. Nicotine increases release of dopamine, so it is hypothesized that smoking helps correct dopamine deficiency in the prefrontal cortex
and thus relieve negative symptoms.
It is unclear, however, how nicotine interacts with positive symptoms, as it would follow from this theory that nicotine would exacerbate excess dopamine in the mesolimbic pathway and thus positive symptoms as well. One theory argues that the beneficial effects of nicotine on negative symptoms outweigh possible exacerbation of positive symptoms. Another theory is based on animal models showing that chronic nicotine use eventually results in a reduction in dopamine, thus alleviating positive symptoms. However, human studies show conflicting results, including some studies that show that schizophrenic smokers have the most positive symptoms and a reduction in negative symptoms.
Another area of research is the role of nicotinic receptors in schizophrenia and smoking. Studies show increased numbers of exposed nicotinic receptors, which could explain the pathology of both smoking and schizophrenia. However, others argue that the increase in nicotinic receptors is a result of persistent heavy smoking, rather than schizophrenia.
Another source of controversy is the relationship between smoking and sensory gating
in schizophrenia. Nicotine may help improve auditory gating, the ability to screen out intrusive environmental sounds. This may help improve attention spans and reduce auditory hallucinations, allowing schizophrenics to perceive the environment more effectively and engage in smoother motor functions. However, research shows this effect alone cannot account for increased smoking rates.
but also natural causes such as cardiovascular disease
, to which smoking is an important contributor. The schizophrenic populations has a higher incidence of smoking diseases, with heart disease deaths 30% more likely and respiratory disease deaths 60% more likely, two times the general population rate. 2/3 of schizophrenics die from coronary heart disease
, versus less than 1/2 of the general population. Ten-year coronary heart disease risk is significantly elevated in schizophrenics, as well as diabetes and hypertension
.
Though smoking may help relieve symptoms of schizophrenia, smoking also counteracts the effects of antipsychotic medication. Smoking results in faster metabolism
of antipsychotics, which results in smokers being prescribed higher doses. Studies are unclear as to whether changes in smoking are caused by changes in symptoms, side effects of medication, or primary effects of medication.
Besides biological effects, smoking has a profound social impact on schizophrenics. One major impact is financial, as schizophrenics have been found to spend a disproportionate amount of their income on cigarettes. A study of schizophrenics on public assistance found that schizophrenics spent a median amount of $142 per month on cigarettes out of a median monthly public assistance income of $596, or about 27.36%. Some argue that this results in further social impacts as schizophrenics are then unable to spend money on entertainment and social events that would promote well-being, or may even be unable to afford housing or nutrition.
. Research based on internal industry documents shows a concerted effort by the industry to promote belief that schizophrenics need to smoke and that it is dangerous for them to quit. Such promotion includes monitoring or supporting research that endorsed the idea that schizophrenics are uniquely immune to the health consequences of smoking (since proved false) and that tobacco is needed for schizophrenics to self-medicate. The industry also provided cigarettes to hospital wards and supported efforts to block hospital-based smoking ban
s. Although this does not discredit the effects of nicotine in schizophrenia, it is argued that the efforts of the tobacco industry slowed the decline in smoking prevalence in schizophrenics as well as the development of clinical policies to promote smoking cessation
.
and disability
and as such should be allowed to engage in smoking as an activity that is pleasurable though destructive. There is also historical precedent of mental health providers, particularly in in patient
settings, to use cigarettes as a way to manipulate patient behavior, such as rewarding good behavior with cigarettes or withholding cigarettes to encourage medication compliance
. However, research showing that eliminating even one risk factor for disease can significantly improve long-term health outcomes has resulted in the dominant view among clinicians opposing smoking.
Though smoking cessation is generally now a goal of mental health clinicians, there is a lack of empirical
research showing successful strategies for accomplishing this goal. However, all studies have shown a reduction in smoking, though not necessarily elimination. Evidence has been found to support the use of sustained-release buproprion, nicotine replacement therapy
, atypical antipsychotics, and cognitive-behavioral therapy. Better outcomes are seen when two or more cessation strategies are employed, as well as for patients using atypical antipsychotics rather than typical antipsychotics. There is also no evidence for an increase in positive symptoms or side effects following smoking cessation, while there is evidence for a decrease in negative symptoms.
Besides smoking cessation, the prevalence of smoking among schizophrenics also calls for additional measures in evaluation by mental health providers. Researchers argue that providers should incorporate tobacco use assessment into everyday clinical practice, as well as continuing assessments of cardiovascular health through measures such as blood pressure
and diagnostics such as electrocardiography. Additionally there are ethical and practical concerns if healthcare facilities prohibit smoking without providing alternatives, particularly since withdrawal can alter the presentation of symptoms and response to treatment and may confuse or even exacerbate symptoms. Clinicians should also be aware of the consequences that can result from a lack of cigarettes, such as aggression
, prostitution
, trafficking
, and general disruption. These consequences indicate that providers may need to help patients obtain cigarettes and/or monitor usage, although this may result in ethical concerns as well.
Schizophrenia
Schizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...
and smoking
Smoking
Smoking is a practice in which a substance, most commonly tobacco or cannabis, is burned and the smoke is tasted or inhaled. This is primarily practised as a route of administration for recreational drug use, as combustion releases the active substances in drugs such as nicotine and makes them...
. For example, in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, 80% or more of schizophrenics smoke, compared to 20% of the general population in 2006.
Though it is well established that smoking is more prevalent among schizophrenics than the general population as well as those with other psychiatric diagnoses, there is currently no definitive explanation for this difference. Many social, psychological, and biological explanations have been proposed, but today research focuses on neurobiology.
Increased rates of smoking among schizophrenics has a number of serious impacts, including increased rates of mortality
Mortality rate
Mortality rate is a measure of the number of deaths in a population, scaled to the size of that population, per unit time...
, increased risk of cardiovascular disease
Cardiovascular disease
Heart disease or cardiovascular disease are the class of diseases that involve the heart or blood vessels . While the term technically refers to any disease that affects the cardiovascular system , it is usually used to refer to those related to atherosclerosis...
, reduced treatment effectiveness, and greater financial hardship. Studies have also shown that in a male population, having a schizophrenia spectrum disorder puts a patient at risk of excess tobacco use. As a result, researchers believe it is important for mental health professionals to combat smoking among schizophrenics.
Causes
A number of theories have been proposed to explain increased rates of smoking among schizophrenics.Psychological and social theories
Several psychological and social explanations have been proposed. The earliest explanations were based on psychoanalytic theoryPsychoanalytic theory
Psychoanalytic theory refers to the definition and dynamics of personality development which underlie and guide psychoanalytic and psychodynamic psychotherapy. First laid out by Sigmund Freud, psychoanalytic theory has undergone many refinements since his work...
. The psychoanalytic hypothesis argued that schizophrenics suffer from an oral fixation, resulting in excessive preoccupation with oral gratification.
The socioeconomic/environmental hypothesis proposed that smoking results because many schizophrenics are unemployed and inactive, so smoking relieves boredom. Research has found that this explanation alone cannot account for the extreme amount of smoking among schizophrenics.
The personality hypothesis focused on the association between smoking and higher level of neuroticism and anxiety. This hypothesis proposed that anxiety as a symptom of schizophrenia may contribute to smoking.
The psychological tool hypothesis argues that smokers use nicotine to manipulate their mental state in response to various environmental conditions, such as reducing stress and managing negative emotions. Research on this hypothesis notes that schizophrenics often have poor coping skills, so use of smoking as psychological tool may result in a vicious cycle of more and more smoking.
The self-medication hypothesis argues that schizophrenics use nicotine to compensate for the cognitive deficits that result from schizophrenia, antipsychotic medication used to treat schizophrenia, or both.
The cognitive effects hypothesis suggests that nicotine has positive effects on cognition, so smoking is used to improve neurocognitive
Neurocognitive
Neurocognitive is a term used to describe cognitive functions closely linked to the function of particular areas, neural pathways, or cortical networks in the brain substrate layers of neurological matrix at the cellular molecular level...
dysfunction.
In these hypotheses, one factor often implicated is the effects of institutionalization and boredom. However, schizophrenics smoke at higher rates and for longer periods than other groups that experience both institutionalization and boredom.
Another factor often implicated is to the side effects
Side Effects
Side Effects is an anthology of 17 comical short stories written by Woody Allen between 1975 and 1980, all but one of which were previously published in, variously, The New Republic, The New York Times, The New Yorker, and The Kenyon Review. It includes Allen's 1978 O...
of antipsychotic medications. Atypical antipsychotics may work against smoking cessation
Smoking cessation
Smoking cessation is the process of discontinuing the practice of inhaling a smoked substance. This article focuses exclusively on cessation of tobacco smoking; however, the methods described may apply to cessation of smoking other substances that can be difficult to stop using due to the...
, as symptoms of smoking cessation such as irritable mood, mental dulling, and increased appetite overlap with side effects of atypical antipsychotics. Some also argue that smoking works to reduce the side effects of antipsychotics. However, research shows no association between smoking and antipsychotic use after controlling for schizophrenia.
Another frequently implicated factor is increased mental acuity associated with smoking, important because of the mental dulling found over time in schizophrenia. However, both schizophrenics and the general population experience this effect, so it cannot fully explain increased smoking in schizophrenics.
Criticisms
One major criticism of social and psychological explanations of smoking in schizophrenia is that most studies have failed to include personal perspectives of patients with schizophrenia. Studies including personal perspectives find that schizophrenics generally start smoking for the same reasons as the general population, including social pressures and cultural and socioeconomic factors. Schizophrenics who are current smokers also cite similar reasons for smoking as non-schizophrenics, primarily relaxation, force of habit, and settling nerves. However, 28% cite psychiatric issues, including response to auditory hallucinations and reduce the side effects of medication. The major themes found in studies of personal perspectives are habit and routine, socialization, relaxation, and addiction to nicotine. It is argued that smoking provides structure and activity, both of which may be lacking in the lives of those with serious mental illness.Another major criticism is based on the finding that the association between smoking and schizophrenia is about as strong across all cultures. This finding implies that the association is not solely social or cultural, but rather has a strong biological component.
Biological theories
Current theory focuses on the role of dopamine in schizophreniaDopamine hypothesis of schizophrenia
The dopamine hypothesis of schizophrenia or the dopamine hypothesis of psychosis is a model attributing symptoms of schizophrenia to a disturbed and hyperactive dopaminergic signal transduction. The model draws evidence from the observation that a large number of antipsychotics have...
, particularly how negative symptoms such as social withdrawal and apathy may be caused by a deficiency on dopamine in the prefrontal cortex
Prefrontal cortex
The prefrontal cortex is the anterior part of the frontal lobes of the brain, lying in front of the motor and premotor areas.This brain region has been implicated in planning complex cognitive behaviors, personality expression, decision making and moderating correct social behavior...
while positive symptoms such as delusion
Delusion
A delusion is a false belief held with absolute conviction despite superior evidence. Unlike hallucinations, delusions are always pathological...
s and hallucination
Hallucination
A hallucination, in the broadest sense of the word, is a perception in the absence of a stimulus. In a stricter sense, hallucinations are defined as perceptions in a conscious and awake state in the absence of external stimuli which have qualities of real perception, in that they are vivid,...
s may be caused by excess dopamine in the mesolimbic pathway
Mesolimbic pathway
The mesolimbic pathway is one of the dopaminergic pathways in the brain. The pathway begins in the ventral tegmental area of the midbrain and connects to the limbic system via the nucleus accumbens, the amygdala, and the hippocampus as well as to the medial prefrontal cortex...
. Nicotine increases release of dopamine, so it is hypothesized that smoking helps correct dopamine deficiency in the prefrontal cortex
Prefrontal cortex
The prefrontal cortex is the anterior part of the frontal lobes of the brain, lying in front of the motor and premotor areas.This brain region has been implicated in planning complex cognitive behaviors, personality expression, decision making and moderating correct social behavior...
and thus relieve negative symptoms.
It is unclear, however, how nicotine interacts with positive symptoms, as it would follow from this theory that nicotine would exacerbate excess dopamine in the mesolimbic pathway and thus positive symptoms as well. One theory argues that the beneficial effects of nicotine on negative symptoms outweigh possible exacerbation of positive symptoms. Another theory is based on animal models showing that chronic nicotine use eventually results in a reduction in dopamine, thus alleviating positive symptoms. However, human studies show conflicting results, including some studies that show that schizophrenic smokers have the most positive symptoms and a reduction in negative symptoms.
Another area of research is the role of nicotinic receptors in schizophrenia and smoking. Studies show increased numbers of exposed nicotinic receptors, which could explain the pathology of both smoking and schizophrenia. However, others argue that the increase in nicotinic receptors is a result of persistent heavy smoking, rather than schizophrenia.
Another source of controversy is the relationship between smoking and sensory gating
Sensory gating
Sensory gating describes neurological processes of filtering out redundant or unnecessary stimuli in the brain from all possible environmental stimuli. Also referred to as filtering, or sensorimotor gating, sensory gating prevents an overload of irrelevant information in the higher cortical...
in schizophrenia. Nicotine may help improve auditory gating, the ability to screen out intrusive environmental sounds. This may help improve attention spans and reduce auditory hallucinations, allowing schizophrenics to perceive the environment more effectively and engage in smoother motor functions. However, research shows this effect alone cannot account for increased smoking rates.
Impacts
Increased smoking among schizophrenics has a number of impacts on this population. One well-documented consequence is the increase in premature death among schizophrenics. Life expectancy among schizophrenics is generally 80-85% that of the general population, which results from both unnatural causes such as suicideSuicide
Suicide is the act of intentionally causing one's own death. Suicide is often committed out of despair or attributed to some underlying mental disorder, such as depression, bipolar disorder, schizophrenia, alcoholism, or drug abuse...
but also natural causes such as cardiovascular disease
Cardiovascular disease
Heart disease or cardiovascular disease are the class of diseases that involve the heart or blood vessels . While the term technically refers to any disease that affects the cardiovascular system , it is usually used to refer to those related to atherosclerosis...
, to which smoking is an important contributor. The schizophrenic populations has a higher incidence of smoking diseases, with heart disease deaths 30% more likely and respiratory disease deaths 60% more likely, two times the general population rate. 2/3 of schizophrenics die from coronary heart disease
Coronary heart disease
Coronary artery disease is the end result of the accumulation of atheromatous plaques within the walls of the coronary arteries that supply the myocardium with oxygen and nutrients. It is sometimes also called coronary heart disease...
, versus less than 1/2 of the general population. Ten-year coronary heart disease risk is significantly elevated in schizophrenics, as well as diabetes and hypertension
Hypertension
Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
.
Though smoking may help relieve symptoms of schizophrenia, smoking also counteracts the effects of antipsychotic medication. Smoking results in faster metabolism
Metabolism
Metabolism is the set of chemical reactions that happen in the cells of living organisms to sustain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories...
of antipsychotics, which results in smokers being prescribed higher doses. Studies are unclear as to whether changes in smoking are caused by changes in symptoms, side effects of medication, or primary effects of medication.
Besides biological effects, smoking has a profound social impact on schizophrenics. One major impact is financial, as schizophrenics have been found to spend a disproportionate amount of their income on cigarettes. A study of schizophrenics on public assistance found that schizophrenics spent a median amount of $142 per month on cigarettes out of a median monthly public assistance income of $596, or about 27.36%. Some argue that this results in further social impacts as schizophrenics are then unable to spend money on entertainment and social events that would promote well-being, or may even be unable to afford housing or nutrition.
Role of tobacco industry
Though the relationship between smoking and schizophrenia is well established, a factor to be considered in this relationship is the role of the tobacco industryTobacco industry
The tobacco industry comprises those persons and companies engaged in the growth, preparation for sale, shipment, advertisement, and distribution of tobacco and tobacco-related products. It is a global industry; tobacco can grow in any warm, moist environment, which means it can be farmed on all...
. Research based on internal industry documents shows a concerted effort by the industry to promote belief that schizophrenics need to smoke and that it is dangerous for them to quit. Such promotion includes monitoring or supporting research that endorsed the idea that schizophrenics are uniquely immune to the health consequences of smoking (since proved false) and that tobacco is needed for schizophrenics to self-medicate. The industry also provided cigarettes to hospital wards and supported efforts to block hospital-based smoking ban
Smoking ban
Smoking bans are public policies, including criminal laws and occupational safety and health regulations, which prohibit tobacco smoking in workplaces and/or other public spaces...
s. Although this does not discredit the effects of nicotine in schizophrenia, it is argued that the efforts of the tobacco industry slowed the decline in smoking prevalence in schizophrenics as well as the development of clinical policies to promote smoking cessation
Smoking cessation
Smoking cessation is the process of discontinuing the practice of inhaling a smoked substance. This article focuses exclusively on cessation of tobacco smoking; however, the methods described may apply to cessation of smoking other substances that can be difficult to stop using due to the...
.
Clinical implications
Given conflicting evidence of the costs and benefits of smoking, controversy remains on what the clinical response to smoking in schizophrenics should be. Historically mental health providers have overlooked smoking in schizophrenia, based on the rationale that patients with serious mental illness already suffer from significant stressStress (biology)
Stress is a term in psychology and biology, borrowed from physics and engineering and first used in the biological context in the 1930s, which has in more recent decades become commonly used in popular parlance...
and disability
Disability
A disability may be physical, cognitive, mental, sensory, emotional, developmental or some combination of these.Many people would rather be referred to as a person with a disability instead of handicapped...
and as such should be allowed to engage in smoking as an activity that is pleasurable though destructive. There is also historical precedent of mental health providers, particularly in in patient
Patient
A patient is any recipient of healthcare services. The patient is most often ill or injured and in need of treatment by a physician, advanced practice registered nurse, veterinarian, or other health care provider....
settings, to use cigarettes as a way to manipulate patient behavior, such as rewarding good behavior with cigarettes or withholding cigarettes to encourage medication compliance
Compliance (medicine)
In medicine, compliance describes the degree to which a patient correctly follows medical advice...
. However, research showing that eliminating even one risk factor for disease can significantly improve long-term health outcomes has resulted in the dominant view among clinicians opposing smoking.
Though smoking cessation is generally now a goal of mental health clinicians, there is a lack of empirical
Empirical
The word empirical denotes information gained by means of observation or experimentation. Empirical data are data produced by an experiment or observation....
research showing successful strategies for accomplishing this goal. However, all studies have shown a reduction in smoking, though not necessarily elimination. Evidence has been found to support the use of sustained-release buproprion, nicotine replacement therapy
Nicotine replacement therapy
Nicotine replacement therapy is the remedial administration of nicotine to the body by means other than tobacco, usually as part of smoking cessation. Common forms of nicotine replacement therapy are nicotine patches and nicotine gum...
, atypical antipsychotics, and cognitive-behavioral therapy. Better outcomes are seen when two or more cessation strategies are employed, as well as for patients using atypical antipsychotics rather than typical antipsychotics. There is also no evidence for an increase in positive symptoms or side effects following smoking cessation, while there is evidence for a decrease in negative symptoms.
Besides smoking cessation, the prevalence of smoking among schizophrenics also calls for additional measures in evaluation by mental health providers. Researchers argue that providers should incorporate tobacco use assessment into everyday clinical practice, as well as continuing assessments of cardiovascular health through measures such as blood pressure
Blood pressure
Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...
and diagnostics such as electrocardiography. Additionally there are ethical and practical concerns if healthcare facilities prohibit smoking without providing alternatives, particularly since withdrawal can alter the presentation of symptoms and response to treatment and may confuse or even exacerbate symptoms. Clinicians should also be aware of the consequences that can result from a lack of cigarettes, such as aggression
Aggression
In psychology, as well as other social and behavioral sciences, aggression refers to behavior between members of the same species that is intended to cause humiliation, pain, or harm. Ferguson and Beaver defined aggressive behavior as "Behavior which is intended to increase the social dominance of...
, prostitution
Prostitution
Prostitution is the act or practice of providing sexual services to another person in return for payment. The person who receives payment for sexual services is called a prostitute and the person who receives such services is known by a multitude of terms, including a "john". Prostitution is one of...
, trafficking
Illegal drug trade
The illegal drug trade is a global black market, dedicated to cultivation, manufacture, distribution and sale of those substances which are subject to drug prohibition laws. Most jurisdictions prohibit trade, except under license, of many types of drugs by drug prohibition laws.A UN report said the...
, and general disruption. These consequences indicate that providers may need to help patients obtain cigarettes and/or monitor usage, although this may result in ethical concerns as well.