Substance-abuse disorders nicotine

Nicotine enhances dopamine release by acting on presynaptic facilitatory heteroreceptors located on the terminal regions of dopaminergic neurons (Marshall et al. 1997). It is tempting to associate these effects of nicotine and the fact that tobacco dependence, the most common substance abuse disorder, is due to nicotine. Nicotine... 

The DRD2 and ANKK1 genes are located approximately 10,000 nucleotides apart on chromosome llq22-23. Variants in both genes have been found to be associated with several psychiatric diseases such as schizophrenia, as well as with substance abuse disorders, including alcohol, heroin, nicotine, cocaine, opioid, gambling, methamphetamine, and polysubstance addiction [30-37]. 

Benzodiazepine abuse is different from other substance abuse disorders (opiates, amphetamines, and nicotine) because benzodiazepines cause much less euphoria and do not activate the classic reward systems that are activated with other substances (mainly the mesolimbic and mesocortical dopaminergic projections). In fact, most people do not find the subjective effects of benzodiazepines pleasant beyond their therapeutic anxiolytic or sleep-inducing effects. Therefore, abuse of benzodiazepines is usually secondary to other substance-abuse disorders, with the benzodiazepine being taken for relief from symptoms induced by the use of another drug. As potential drugs of abuse, short-acting benzodiazepines seem to be preferred among addicts because of the rapidity of their onset of action (aiprazoiam, fiunitrazepam, and iorazepam). 

Glassification of Substance-Related Disorders. The DSM-IV classification system (1) divides substance-related disorders into two categories (/) substance use disorders, ie, abuse and dependence and (2) substance-induced disorders, intoxication, withdrawal, delirium, persisting dementia, persisting amnestic disorder, psychotic disorder, mood disorder, anxiety disorder, sexual dysfunction, and sleep disorder. The different classes of substances addressed herein are alcohol, amphetamines, caffeine, caimabis, cocaine, hallucinogens, inhalants, nicotine, opioids, phencyclidine, sedatives, hypnotics or anxiolytics, polysubstance, and others. On the basis of their significant socioeconomic impact, alcohol, nicotine, cocaine, and opioids have been selected for discussion herein. 

Within this Held, most of the research and results have been focused on the effects of drug therapy on the disorders induced by alcohol, and by the abuse of opiates. For a broader discussion of substance abuse see Chapter 18. In all instances of alcohol or drug abuse the first objective is to wean the patients from the addictive substance, treating or preventing the effects of withdrawal for those substances which cause physical dependence (alcohol, nicotine, opiates, caffeine, certain psychotropic agents such as benzodiazepines, possibly antidepressants). The second phase is the prevention of recurrence or relapse, which relies on a combination of social support, psychotherapy, and pharmacotherapy where available. In this respect, alcoholism is exemplary. 

Is the nicotine patch an effort to modify human mental activity Will a brain Polypill be developed to treat persons susceptible to substance abuse, such as cocaine We now know that cocaine and methamphetamine flood the brain with dopamine and other neurotransmitters,producing a"high. Methamphetamine (meth),prescribed for patients with severe attention-deficit hyperactivity disorder or narcolepsy, is widely abused. Crystal meth is the crystalline form of the drug that is smoked. It is difficult to imagine that there will ever be supplementation of a communal water supply, but we should remember that salt is iodized, there is fluoride in water and iron and folic acid are supplements in many foods. 

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