Medical brain notes 45

  Substances of Dependence and Abuse Use of psychoactive substances to experience pleasurable effects is not a recent phenomenon, but has been indulged in by human kind for hundreds, even thousands of years. Terminology in the field of substance abuse has changed frequently leading to a great deal of confusion. Therefore, it is necessary to begin this section by defining currently used terms, and to clarify the differences between them. The nomenclature and diagnostic schemes mentioned here -in are based on the 4th edition of Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), and the 10th edition of International Classification of Diseases and Related Health Problems (ICD-10).   DEFINITIONS Substance Dependence Substance dependence arises out of a maladaptive pattern of substance use, leading to a cluster of behavioural, cognitive, and physiological phenomena that develop after repeated intake. It includes a strong desire to take the drug, difficulties in control-ling its

  CLASSIFICATION ·                Ethanol ·                Tobacco ·                Tranquillisers and Sedatives Barbiturates, benzodiazepines, chloral hydrate, chlorme-thiazole, ethchlorvynol, glutethimide, hexapropymate, meprobamate, methyprylon, methaqualone, zolpidem, zopiclone ·                Opiates and Opioids ·                Cocaine ·                Cannabis ·                Amphetamines and “Designer Drugs” ·                Hallucinogens Lysergic acid diethylamide (LSD), phencyclidine, psilo-cybine, bufotenine, mescaline, ketamine, diethyltrypt-amine (DMT) ·                Inhalants Fluorinated hydrocarbons (freons), ethers, ketones, aromatic and aliphatic hydrocarbons ·                Miscellaneous Substances  Caffeine, datura seeds, analgesics, anabolic steroids, cough syrups, laxatives Several of these compounds have been discussed in detail elsewhere, and the reader is advised to consult the  Index  for locating them. The remaining will be discussed inthis section. Globa

  Tobacco Sources ·        Nicotiana attenuata  (Wild tobacco) ·        Nicotiana glauca  (Tree tobacco) ·        Nicotiana longiflora  (Cultivated ornamental) ·        Nicotiana rustica ·        Nicotiana tabacum  (Commercial tobacco) ·                Nicotiana trigonophylla  (Desert tobacco). Tobacco is usually prepared from cured leaves of  Nicotianatabacum  ( Fig 34.1 ) belonging to family Solanaceae. Turkishtobacco is prepared from the leaves of  Nicotiana rustica , and is more potent. Indian tobacco refers to  Lobelia inflata . Active Principles ·                Nicotiana tabacum  and  N.rustica  contain the following alka-loids: ·                Nicotine ·                Nornicotine ·                Anabasine ·                Anabatine. Nicotiana tabacum  is an annual herb, shrub, or small tree; from0.90 to 1.50 metres tall according to the variety. The leaves are elliptical or oblanceolate; flowers are clustered at the end of the branches and have a cylindrical calyx, being gre