Diseño, estudio de precisión y evidencias de la validez de una nueva batería neuropsicológica para la prevención de recaídas de pacientes con trastorno por consumo de sustancias

Laburpena

The doctoral thesis presented below has been aimed at the design, as well as the study of accuracy and evidence of validity of the scores of a new battery of neuropsychological tests for the prevention of relapse in patients with substance use disorder. In its totality, this investigation consists of seven chapters distributed in three blocks. Throughout the first block, the theoretical framework that has served as the basis for the main objective of the study is presented. This block contains chapter 1, which deals with epidemiological data, the consumption of substances during the last decade and the high relapse rates associated with this problem. Through the main theoretical models in relation to the addictive process and summarizing the empirical evidence provided by the literature, attention has been focused on several cerebral circuits involved in the relapse and on their corresponding neuropsychological correlates. The second block, formed by chapter 2, begins by specifying the general objective of the study, as well as the specific objectives. These are synthesized in the following: (i) identify the executive functions that have been shown to be more related to relapse and therapeutic adherence; (ii) design a task to evaluate the attentional bias towards consumption stimuli and provide evidence of validity in relation to the results of the treatment; (iii) design a task to evaluate the decision making and provide evidence of reliability and validity in relation to the results of the treatment and (iv) design a task to evaluate the motivational preference towards stimuli related to consumption and provide evidence of reliability and validity in relation to the results of the treatment. This chapter is complemented with the description of the process of elaboration of the test that underlies the development of each one of the tasks integrated in the neuropsychological battery, as well as the methodological characteristics of the research that has ended by contrasting the psychometric properties of the designed tasks. The third block corresponds to the research results. In this block a total of four chapters are presented where the studies carried out are collected (a systematic review and three empirical studies). The first of them is detailed in chapter 3 and corresponds to a systematic review study that synthesizes the research carried out since 2000 to 2015, in which the executive functioning has been evaluated through neuropsychological tasks with the objective of predicting relapse and adherence to treatment in substance-dependent patients. The results of this study showed the high variability in the set of evidence found in terms of the domain evaluated, the task used and the substance used. In the same way, it could be observed the inexistence of executive function evaluation instruments designed specifically for this population. Regarding the results of the treatment, this study showed that the components that showed a greater relationship with adherence and relapse were the component of general cognition, evaluated through the MicroCog battery, and decision making, frequently evaluated through of the Iowa Gambling Task. As a whole, the results of this study served as support to justify the need to develop measurement instruments specifically designed for patients consuming substances, which was the main objective of this research. Chapter 4 presents an empirical study carried out with a new task, called Drug Visual Probe, designed to evaluate the attentional bias towards consumption stimuli under the Visual Probe paradigm, in cocaine-dependent patients and alcohol users. This study corresponds to the second specific objective. The results obtained showed that the attentional bias towards stimuli related to alcohol had a predictive capacity on adherence to treatment in cocaine-dependent patients. The analysis of the patterns of attentional bias showed a pattern of avoidance towards these stimuli in patients who left the treatment. However, the patients who remained in treatment showed a pattern of approach towards consumption stimulus. Chapter 5 presents the results related to the third specific objective, designing a task to evaluate the decision making in consumers of substances and provide evidence of reliability and validity in relation to the results of the treatment. This study was carried out with patients dependent on cocaine and / or alcohol. The psychometric results of this new designed task (Deciding About Your Health) showed, in a general way, reliability coefficients estimated through the test-retest procedure compatible with its use. Regarding the evidence of validity in relation to the therapeutic results, the study showed that patients with an execution in the task towards obtaining immediate rewards and with a lower valuation towards future consequences, had a higher probability of relapse. Thus, in outpatient treatment, the performance in blocks 2 and 3 of the task had predictive capacity on relapse to alcohol, and performance in block 1 predicted relapse to cocaine in the residential treatment modality. Chapter 6 presents the last of the empirical studies carried out in this investigation. Corresponding to the last specific objective, a task was designed to evaluate the motivational preference towards stimuli related to consumption (Word Association Task for Drug Use Disorder). The results of this study showed good psychometric properties in terms of reliability through the study of internal consistency and test-retest stability for all the indicators of the task. In terms of validity based on the relationship with other variables, the study showed that patients with a higher level of craving to cocaine and alcohol, greater severity of alcohol dependence and greater amounts of withdrawal symptoms, presented a greater choice of drug-related words in response to ambiguous images. Finally, in terms of evidence of validity in relation to the therapeutic results, the results of the study indicated that the group of patients who relapsed manifested an avoidant pattern towards explicit consumption stimuli (greater number of words not related to the drug chosen together with shorter response times). The third and last block of this thesis contain the discussion of the results found. This block corresponds to Chapter 7, where the theoretical and clinical implications of the results found in this research are also developed. Finally, within the same chapter, conclusions of the research are presented.