Abstract: In the recent years several drugs with an anticraving effect have been developed. These drugs should reduce the urge to drink alcohol. In the near future some of these drugs with different pharmacological profiles will be introduced to several European countries. That’s why a critical review of the psychobiological concept craving is necessary. Although widely used craving is an illdefined term. Craving has been associated with different psychological concepts that are mostly based on behavorial theories. Furthermore, some biochemical findings probably associated with craving are reviewed. However, thus far the assessment of craving is based on self-reports, since it is a subjective cognition like pain. The magnitude of craving depends on situational factors, varying with time and place. Thus, a sufficient assessment has to include the conditions and expectancies occurring together with craving.

Abstract: Crack is a potent form of cocajne which results in rapid and striking stimulant effects when smoked. This paper reviews epidemiological research on the extent of use as well as reports of adverse effects. Crack is used b a small minority of adult and student populations but by a larger proportion of cocaine users and .heavy drug-using groups. Use does not appear to be increase in general popuations, but there are no trend studies for high-risk groups. Crack users tend to be young, heavy polydrug users, many of whom have serious drug abus problems. The adverse reactions to crack are similar to those of cocaine and include effects on offstpring, neurological and psychiatric problems, as well as pulmonary and cardiac abnormalities. However, two adverse reactions unique to crack have been reported. One relates to lung infiltrates and bronchospasm. The other involves neurological symptoms among children living in crack smoked-filled rooms. There is a need for improved treatment and preventive programs for crack use.

Abstract: Documented crack use emerged in São Paulo, Brazil, from 1991 onward. Therefore, it is a recent behavior among drug users. The present work draws a profile of São Paulo crack users, employing an ethnographic approach. Twenty-five crack users were interviewed on selected social and demographic characteristics, on the drug itself and its consumption, and on the consequences of this use. Crack cocaine is harmful for the user, leading within a short period to a condition of dependence. The crack users reported ultimately lapsing into “marginality” due to social isolation, neglect of bodily needs, and breakdown of family ties and other relationships.

Abstract: alcohol exei.ts numerous pharmacological effects through its interaction with various neurotransmitters and neuromodulators. Among the latter, the endogenous opioids playa key role in the rewarding (addictive) properties of ethanol. Three types of opioid receptors represent the respective targets of the major opioid peptides (p-endorphin, enkephalins and dynorphins, respectively). The rewarding (reinforcing) properties of 11- and 8-receptor ligands are brought about by activation of the mesolimbic dopamine system which ascends from the ventral tegmentum of the midbrain (VTA) to rostral structures: of these, the nucleus accumbens (NAC) is of particular importance in drug addiction. In contrast, dysphoria results from activation of K-receptors. The neurochemical manifestations of these opposing effects are, respectively, increases and decreases in dopamine release in the NAC. Several lines of evidence indicate that alcohol interferes with endogenous opioid mechanisms which are closely linked with dopamine transmission in the mesolimbic pathway. The view that condensation products of dopamine and alcohol-derived aldehyde (tetrahydroisoquinolines) playa role remains controversial. There is. however, much information on the direct (acute and chronic) effects of alcohol on the binding properties of opioid receptors, as well as modulation of opioid peptide synthesis and secretion (e.g. a suggested increase in p-endorphin release). In view of the reinforcing properties of alcohol. it is relevant to consider behavioural studies involving alcohol self-administration in rodents and primates. Low doses of morphine have been found to increase. and higher doses of the opiate to decrease, alcohol consumption. Conversely, opi()id antagonists such as naloxone and naltrexone (which bind to non-selectively opioid receptors) have been shown to decrease alcohol consumption under various experimental conditions. Similar results have been reported when selective 11- or b-receptor antagonists are administered. Results obtained in genetic models of high preference for alcohol also support the view that alcohol intake depends on the activity of the endogenous opioid reward system and that alcohol consumption may serve to compensate for inherent deficits in this system. One hypothetical model proposes that reward results from activation of opioid receptors in the VTA and/or b-receptors in the NAC; both these nuclei are targets of endogenous p-endorphin. It is suggested that alcohol interferes with this reward pathway either directly or indirectly. The available experimental data accord well with those obtained from clinical studies in which opioid antagonists have been used to prevent relapse in alcoholics. Conceptual considerations concerning communalities between various forms of addictions are also discussed in this review.