Additional information on nicotine-related disorders
Additional Information on Nicotine-Related Disorders
Associated Features and Disorders
Associated descriptive features and mental disorders.
Craving is an important element in Nicotine Withdrawal and may account for the difficulty that individuals have in giving up nicotine-containing products. Other symptoms associated with Nicotine Withdrawal include a desire for sweets and impaired performance on tasks requiring vigilance. Several features associated with Nicotine Dependence appear to predict a greater level of difficulty in stopping nicotine use: smoking soon after waking, smoking when ill, difficulty refraining from smoking, reporting the first cigarette of the day to be the one most difficult to give up, and smoking more in the morning than in the afternoon. The number of cigarettes smoked per day, the nicotine yield of the cigarette, and the number of pack-years also are related to the likelihood of an individual stopping smoking. Nicotine Dependence is more common among individuals with other mental disorders such as Schizophrenia. Depending on the population studied, from 55% to 90% of individuals with other mental disorders smoke, compared to 30% in the general population. Mood, Anxiety, and other Substance-Related Disorders may be more common in individuals who smoke than in those who are ex-smokers and those who have never smoked.
Associated laboratory findings.
Withdrawal symptoms are associated with a slowing on EEG, decreases in catecholamine and cortisol levels, rapid eye movement (REM) changes, impairment on neuropsychological testing, and decreased metabolic rate. Smoking increases the metabolism of many medications prescribed for the treatment of mental disorders and of other substances. Thus, cessation of smoking can increase the blood levels of these medications and other substances, sometimes to a clinically significant degree. This effect does not appear to be due to nicotine but rather to other compounds in tobacco. Nicotine and its metabolite cotinine can be measured in blood, saliva, or urine. Persons who smoke also often have diminished pulmonary function tests and increased mean corpuscular volume (MCV).
Associated physical examination findings and general medical conditions.
Nicotine Withdrawal may be associated with a dry or productive cough, decreased heart rate, increased appetite or weight gain, and a dampened orthostatic response. The most common signs of Nicotine Dependence are tobacco odor, cough, evidence of chronic obstructive pulmonary disease, and excessive skin wrinkling. Tobacco stains on the fingers can occur but are rare. Tobacco use can markedly increase the risk of lung, oral, and other cancers; cardiovascular and cerebrovascular conditions; chronic obstructive and other lung diseases; ulcers; maternal and fetal complications; and other conditions. Although most of these problems appear to be caused by the carcinogens and carbon monoxide in tobacco smoke rather than by nicotine itself, nicotine may increase the risk for cardiovascular events. Those who have never smoked but are chronically exposed to tobacco smoke appear to be at increased risk for conditions such as lung cancer and heart disease.
Specific Culture, Age, and Gender Features
The prevalence of smoking is decreasing in most industrialized nations but is increasing in the developing areas. African American men tend to have higher nicotine blood levels for a given number of cigarettes compared with other racial groups, which might contribute to greater difficulty in cessation of smoking. The highest lifetime prevalence of use of nicotine, in contrast to other drugs, is in older individuals. In the United States, the prevalence of smoking is slightly higher in males than in females; however, the prevalence of smoking is decreasing more rapidly in males than in females. In other countries, smoking is often much more prevalent among males. Use of smokeless tobacco is much higher in males than females, with males outnumbering females 8 to 1 or more.
Prevalence
There were fairly substantial decreases in regular smoking and Nicotine Dependence in most groups in the 1980s, followed by a leveling off of this rate of decline, estimated to be only 2% or less in the late 1990s. Greater levels of decrease were seen for men than for women, and for Caucasian individuals than for those of African American or Hispanic background. Several groups have shown an actual increase in the prevalence of regular smoking or Dependence in the mid-1990s, especially women who have less than a high school education.
A 1996 national survey of drug use reported that 72% of the adult population in the United States had ever used cigarettes, with 32% reporting use in the prior year and 29% reporting use in the prior month. The lifetime prevalence in the United States was highest among individuals aged 35 and older (78%), although use in the prior year and prior month was highest for people between ages 18 and 25 (45% and 38%, respectively). The 1996 survey also indicated substantial rates of use of smokeless tobacco, with 17% of the U.S. population acknowledging ever having used these products, and 5% reporting use in the prior month. Surveys of drug use in high school students indicate that tobacco use in the younger population is on the rise. According to a 1997 survey of 12th-graders, 65% reported ever having used cigarettes-an increase over the 1994 proportion of 62% (but not as high as the peak lifetime prevalence of 76% in 1977).
Since it is estimated that between 80% and 90% of regular smokers have Nicotine Dependence, up to 25% of the U.S. population may have Nicotine Dependence. The rate of Nicotine Dependence has been shown to be higher in individuals with Schizophrenia or Alcohol Dependence than in the general population.
Course
Nicotine intake usually begins in the early teens, with 95% of those who continue to smoke by age 20 becoming regular daily smokers. More than 80% of smokers report attempting to quit, but during the first attempt, less than 25% of those who do abstain remain successful for extended periods of time. In the longer run, about 45% of those who consume nicotine on a regular basis are able to stop smoking eventually. For the large majority of smokers who have Nicotine Dependence, cessation of cigarette smoking usually results in withdrawal symptoms that begin within a few hours of cessation and typically peak in intensity between the first and fourth days, with most residual symptoms greatly improving by 3 to 4 weeks, but with hunger and weight gain persisting for 6 months or more. This off-and-on again course and repeated desire for abstinence probably apply equally to consumption of other forms of nicotine, including chewing tobacco.
Familial Pattern
The risk for smoking increases threefold if a first-degree biological relative smokes. Twin and adoption studies indicate that genetic factors contribute to the onset and continuation of smoking, with the degree of heritability equivalent to that observed with Alcohol Dependence.
Differential Diagnosis
For a general discussion of the differential diagnosis of Substance-Related Disorders, see p. 207.
The symptoms of Nicotine Withdrawal overlap with those of other substance withdrawal syndromes; Caffeine Intoxication; Anxiety, Mood, and Sleep Disorders; and medication-induced akathisia. Admission to smoke-free inpatient units can induce withdrawal symptoms that might mimic, intensify, or disguise other diagnoses. Reduction of symptoms associated with the resumption of smoking or nicotine-replacement therapy confirms the diagnosis.
Because regular nicotine use does not appear to impair mental functioning, Nicotine Dependence is not readily confused with other Substance-Related Disorders and mental disorders.