**1. Introduction**

### **1.1 Adolescence and substance abuse**

People are most likely to begin abusing drugs (including tobacco, cannabis, alcohol, and other illicit substances) during adolescence and young adulthood from ages 10 to 19 [1]. Adolescence is a particularly vulnerable period of neurodevelopment in which the incorrect management of emotional, social, and behavioral changes can lead to an unsuccessful adulthood [2]. Regarding the brain anatomy and function, it is well known that during this period of life the brain is still maturating, being a moment of dynamic specialization of core brain systems, particularly the frontal structures [3]. In fact, the neural plasticity that occurs during this period creates a unique opportunity to influence the behavioral and developmental trajectories [4]. It is also a difficult period in which a high percentage of their decisions rely more on an emotional response or even on the social rewards rather than in a logical response. Therefore, as Hall noted in 1904, adolescence is a period of *storm and stress* (revised in [5]) because adolescents are characterized by a greater impulsivity, and less control over impulses, behaviors, and emotions, as well as a heightened reward sensitivity [6, 7]. As consequence, these personality, cognitive and behavioral patterns contribute to the emergence of risky and disruptive behaviors, such as drug abuse, which is common in Western countries [8].

This increased propensity to consume drugs is also enhanced by the fact that adolescents tend to be significantly less sensitive to their effects than adults [9]. Hence, adolescents experience less hangover symptoms and negative affect during alcohol withdrawal [10]. Besides, longitudinal studies have also suggested that impulsivity and the lack of inhibitory control could predict early onset drinking and alcohol dependence [11, 12]. On the other hand, alcohol consumption can promote itself impulsive actions by impairing basic inhibitory process [13]. Specifically, adolescents often consumed alcohol in repeated short episodes of heavy intake followed by detoxification and extended periods of abstinence, known as binge drinking (BD) [14]. This drinking pattern consists in drinking 5 or more glasses of alcoholic beverages in short periods of time (2 h) increasing the blood alcohol concentration above 80 mg/dl [15, 16]. Several preclinical and clinical studies have revealed that BD is associated with long-term behavioral and

neurobiological impairments along with a risk of dependence in adulthood [17]. Nowadays, it is estimated that 40% of people between the ages of 15 and 24 engage in this pattern of alcohol consumption, which contributes to several medical complications, as well as higher risk of developing alcohol use disorder [18]. Further, the potential role of substance use as a risk factor for adult psychiatric disorders and dependence is remarkable [19]. These negative consequences are due in part to the drugs impact on brain mechanisms and signaling systems, whose maturation mainly happens during adolescence [9]. Thereby, in general, early drug exposure can produce impairments in the brain structure and function, resulting in several emotional, behavioral, and cognitive deficits [20]. For instance, studies have revealed persistent alcohol-induced neurobiological changes within the prefrontal cortex, the hippocampus, and the amygdala integrally involved in governing diverse emotional states [21–23].

Earlier initiation of substance use in adolescence is associated not only with an increased risk of dependence but also with antisocial behavior and impairments of adaptive functioning, including relationship difficulties, academic failure, unemployment, and mental health issues [24–26]. Besides, over half of the adolescents receiving treatment will relapse within 1 year of treatment [27], suggesting more accessible and effective programs needed to prevent and treat substance abuse in adolescents. Consequently, there is a need to explore other alternatives to treatment that, alone or in combination with existing ones, representing an improvement in treatment [28, 29].

Despite the relevance and clear influence of personality and neuropsychological factors in the development of substance abuse behaviors, we should not neglect the study of the impact of family dynamics and the social environment in which these young people live as possible predisposing variables. Regarding family factors, some studies have observed that young people who engage in substance abuse perceive a lower quality of family functioning with lower levels of cohesion, flexibility, communication, satisfaction, and a higher degree of disengagement compared with healthy adolescents [30]. Moreover, living in families that are not very flexible, highly disengaged and with communication problems among their members, is also a risk factor, suggesting the importance of prevention programs being based on an integrated approach focused also on improving the family environment. On the other hand, it has been observed that children of parents who also have addiction problems are more likely to present excessive consumption of drugs [31]. Nevertheless, there is also literature that did not find a significant association between parental drug consumption and substance abuse in adolescence [32]. Finally, another important social factor, especially for young people, is their use of social networks. Thus, it has been observed that the content of these is poorly regulated, tending to use marketing tactics based on the vulnerability of young people to the image, social relationships, and their need to fit in with the group [33]. To date, there is little work that has investigated the behavioral profiles of young people with drug-related problems on social networks, although this could have interesting implications for treatment and prevention. **Figure 1** summarizes different risk factors involved in substance abuse during adolescence.

Therefore, this book presents a comprehensive overview of multidisciplinary issues about adolescence and substance abuse, especially focus on alcohol. It has been written to be consulted by students and professionals of multiple psychological, biological, and social disciplines. Chapters has been also written for academics and researchers on different areas focusing on risk factors related to the onset and

*Introductory Chapter: Adolescent Substance Abuse – Risk Factors and Consequences DOI: http://dx.doi.org/10.5772/intechopen.108015*

### **Figure 1.** *Variables associated with drug abuse during the adolescence and youth.*

maintenance of substance abuse in adolescence, as well as potential of behavioral and pharmacological approaches to prevent and/or reduced the negative consequences involved in substance abuse. Finally, psychological disorders associated with drug abuse are also considered in this book.
