Brain Mechanisms Controlling Drug Addiction Reinforcement

Brain Mechanisms Controlling Drug Addiction Reinforcement Discuss how theories relate drug addiction to endogenous brain mechanisms controlling reinforcement, and look at how these theories may be used to improve the effectiveness of treatment of addiction In psycho-biological terms addiction is regarded as the perceived need for a drug or substance and the potential for the subsequent re-use of that substance often manifesting itself in a pattern of drug induced behaviour. This has indicated a connection between the behavioural pattern of a user and the biological cravings that are associated with this pattern of behaviour. Due to this relationship between dependent and abusive behaviour patterns and the biological and psychological cravings for the wanted substances, research has gone into establishing the effects of drug addiction and their basis in psychology resulting in many neurobiological models. In terms of patterns of behaviour, operant conditioning provides a convenient, easy and reliable way of adjusting any subject’s pa ttern of behaviour under the conditioning of a controlled and changeable environmental. This has been conducted in research in an easily observable manner that was then able to account for factors pertaining to addiction and the potential for abuse through accordance to a pre-devised model. Through the notions of positive regard, response and reward and through shaping behaviours this could then be adjusted to test any independent variable. This acts as a convenient methodology for observing the effects of drugs and was devised by early Psychopharmacological researchers in a bid to examine the relationship between drug use and behaviour patterns. One such piece of seminal research that incorporated this relationship was conducted by Dews (1953). In his founding study, Dew began a program of operant studies in an attempt to observe the behavioural effects of drugs to see how it could act as a precursor for addiction. His initial experiments on the behavioural patterns observed in ani mals led to the establishment that a schedule of reinforcement maintaining a pattern of behaviour could play a critical role in determining the effects of a drug (Dews, 1955). Through operant conditioning and behavioural observation he was able to discern that the dose-effects of the drugs used in his experiment varied in terms of performances that were maintained under two different schedules of reinforcement. However, he was also able to observe that there was a dose range in which the rate of behaviour would increase in one schedule condition, whilst it decreased in the other condition. This was an early indication that drug addiction depended upon the schedule as much as it did the dosage. Essentially, addiction was determined by patterns of behaviour as much as patterns of behaviour were determined by drug usage. In these early experiments, Dews was able to ascertain that stimulants would increase the probability of a pattern of behaviour as it pertained to the relevant classif ication of a drug. However, he was also able to note that the drug could decrease the probability of any given pattern of behaviour itself. This research indicated that there was a variety of concepts at play within the role of addiction, such as tolerance, abuse, dependency and reward. In contemporary research, we can see that these factors have been incorporated in an attempt to identify the mechanisms in the brain that lead to dependency, abuse and addiction through the parsing of reward. This was devised by Berridge et al (2003) as the investigation to find the neuro-pharmacological basis for three main psychological components essential to the parsing of reward and onset of addiction. These were the concepts of learning that included the explicit and implicit knowledge produced by associative conditioning and cognitive processes, an affect or emotion such as implicit ‘liking’ and conscious pleasure associated with the experience of the drug, and motivation; suggest ed as the implicit incentive salient ‘wanting’ and the accompanying cognitive incentive goals. Essentially, this three way split revealed that learning (Dews schedules of reinforcement), craving (the perceived effect of the drug) and habit (Dews patterns of behaviour) were the major contributing and operating factors in the role of addiction.