Agressividade e impulsividade em homens hospitalizados por uso de substâncias psicoativas

Abstract

It is known that psychoactive substances lead to health risks and increases the likelihood of exhibiting aggressive behaviors, which happens more often in the male population. Furthermore, addicts, or people who present reward pathologies, value their object of addiction more than other pleasures. As the severity of the substance use disorder progresses, the addict’s motivation for substance use increases, while his/her motivation for natural pleasures decreases. Another relevant factor is Impulsivity. Studies have shown that people who present high impulsivity, measured by selfreports, have a higher likelihood of presenting substance use and poor decision making. Aggression can be divided in four traits: physical aggression; verbal aggression; anger; and hostility. The first two represent the tendency to hurt or harm others. Anger refers to arousal and to the preparation for aggression. Hostility consists of feelings of ill will and injustice from other people. Impulsivity can be divided in three main traits: Neuroticism/Negative Urgency, Disinhibition versus Constraint, and Extraversion/Positive Emotionality. The Disinhibition versus Constraint is related to the lack of planning and persistence. Extraversion/Positive Emotionality form Sensation Seeking. Last, Neuroticism/Negative Emotionality form Negative Urgency, the tendency to act abruptly to avoid negative emotions (e.g., stress, craving). There is evidence of positive association between Impulsivity and Aggression. It is believed that aggressive episodes occur more by impulsivity than by planning, as suggested by a study from Stanford and colleagues. The study assesses 93 physically aggressive men and 90% of them presented impulsive aggression, whereas only 10% presented premeditated aggression. Therefore, this dissertation aims to contribute with the knowledge in the substance abuse field, with the objective of determining the main factors that associate with Aggression and Impulsivity in drug users. Thus, two studies were developed: 1) Relation between cocaine use, impulsivity, and aggression; 2) Delay Discounting in tobacco smokers. In the first and second studies, the samples consisted of 121 and 70 participants, respectively. The first study aimed to better understand the association between Cocaine (both snorted and smoked), Impulsivity, and Aggression, whereas education, snorted Cocaine onset, and Urgency, an Impulsivity trait, were the main factors associated to Aggression. Furthermore, there was evidence of association between perceived severity of Cocaine use and Urgency. Therefore, it is clear that Urgency is an important factor to be investigated when treating inpatients who present Cocaine use. The second study aimed at comprehending the relation between Tobacco, Executive Functions, and Delay Discounting (an impulsivity measurement). Results indicate that tobacco smokers with lower income or social status, or are older have a tendency towards more Delay Discounting, hence favoring lower immediate rewards over late rewards. It is observed that Urgency and Cocaine onset have an important role in Aggression. Therefore, in order to have information regarding the Aggression of patients who use Cocaine, it would be important to develop an assessment specific for Urgency and to know the first time Cocaine was used by the patient. Moreover, it should be noticed that Tobacco smokers with lower social status are likely to present more Impulsivity, just like Cocaine users with lower education. For future studies, the creation or employment of a test specifically designed to measure Urgency is recommended, considering that this was the main Impulsivity trait to correlate with Cocaine use and Aggression. Additionally, treatments that focus in decreasing Urgency would probably benefit this population. Another recommendation would be to develop similar studies, but with a comparison group, such as a group of inpatients who were hospitalized for drug abuse, but do not present Cocaine use, or a group from the healthy population. The same is recommended for future studies addressing Tobacco smoking and Delay Discounting, with a group of smokers and a group of non-smokers. Such comparison would allow shedding light on which characteristics are specific of the target population.