Alcohol and alcoholism : international journal of the Medical Council on Alcoholism
-
Review
Interactions between cannabinoid and opioid receptor systems in the mediation of ethanol effects.
Over the past few years, advances in the investigation of the neurochemical circuits involved in the development and treatment of alcohol dependence have identified peptides and receptors as potential key targets in the treatment of problems related to alcohol consumption. The endogenous opioid system is modified by alcohol intake in areas of the brain related to reward systems, and differential basal levels of opioid gene expression are found in rodents with a high preference for ethanol. This suggests a greater vulnerability to alcohol consumption in relation to differences in genetic background. ⋯ Abundant evidence indicates that the activation of cannabinoid receptors stimulates the release of opioid peptides, therefore the cannabinoid receptor antagonists may presumably alter opioid peptide release, thus facilitating the reduction of ethanol consumption. However, little is known about the effects of ethanol on the endogenous cannabinoid system, the vulnerability of cannabinoid receptors to alcohol intake or their neurochemical implications in reducing consumption of alcohol. In this paper, we review the role of opioid and cannabinoid receptor systems, their vulnerability to alcohol intake and the development of dependence, and the targeting of these systems in the treatment of alcoholism.
-
In this article, by reviewing the psychological, psychophysiological, neurobiological, and psychopharmacological literature on craving for alcohol, it is argued that converging evidence from several disciplines suggests a three-pathway psychobiological model of craving. Essential to this model is the appreciation of the role of individual differences in affect regulation strategies or personality styles, conditionability, sensitivity to alcohol's effects, and related dysregulations in distinct neural circuitries or neurotransmitter systems. These factors are of crucial importance to a proper understanding of the nature of craving, its underlying mechanisms and different manifestations. ⋯ Obsessive craving, the result of the third pathway, can be defined as lack of control over intrusive thoughts about drinking resulting in impaired functioning. This type of craving might result either from a serotonin deficiency or a personality style characterized by low constraint or disinhibition or a combination of both. The putative implications of this three-pathway model for the assessment of alcohol craving, diagnosis and treatment of alcoholism, and future research on craving, are discussed.
-
Increasing evidence suggests that craving may play a central role in the mechanisms of addiction. The experience of craving is largely characterized by obsessional thoughts about drugs, triggering compulsive drug-seeking and drug-taking behaviour. In the present article the possible involvement of brain 5-hydroxytryptamine (5-HT) in the mechanisms of craving and relapse is discussed by integrating the results of basic research with those obtained in human studies. Based on studies suggesting that the brain serotonergic system plays a central role in the regulation of impulse-control mechanisms, it is proposed that 5-HT deficiency may contribute to the loss of control over drug-taking, which is a crucial factor for the maintenance of addictive behaviour.
-
Almost all evidence of a link between alcohol consumption and violence is available only in the form of aggregate data. This is unsatisfactory and case-control investigations and studies which relate injury severity to blood alcohol levels are needed. In the few closely controlled studies which have been performed, increased risk of injury in assault has been linked with binge consumption of more than about 8 units, and above average weekly consumption only in those over 25 years. ⋯ The use of sobriety-checkpoints (breath testing though not by the police) and other situational prevention programmes need to be evaluated in relation to reducing injury sustained in violent crime. Proactive, community policing has been shown to reduce levels of alcohol-related violent crime, in contrast to more reactive, defensive and confrontational policing. The concept of 'capable guardianship' to establish and maintain social control of young delinquents needs to be extended, particularly near known foci of violence such as bars and adjacent fast-food outlets and taxi-ranks.
-
In psychiatric practice, lithium prevents manic depressives recidivism. Lithium could also be useful in non-manic-depressive conditions with a reduction of aggression and impulsivity. From the observation that alcoholics often present mood swings and impulsivity, several authors studied the effects of maintenance doses of lithium on alcohol intake and the depressive symptoms of alcoholics. ⋯ Most of the recent studies failed to demonstrate a significant effect of lithium on the depressive symptoms of alcoholics. Thus, it is now established that lithium is not an effective treatment of affective disorders in alcoholics. The latest published studies also suggest that lithium treatment does not decrease alcohol intake or craving for alcohol in either depressed or non-depressed alcoholics.