Archives of Psychiatric Nursing 28 (2014) 295–296
Contents lists available at ScienceDirect
Archives of Psychiatric Nursing journal homepage: www.elsevier.com/locate/apnu
Child & Adolescent Mental Health Section
The Adolescent Brain: An Overview of Recent Research Kathleen R. Tusaie Univ of Akron
The past method of studying brain function has been to study those who have had some type of pathological brain damage and then identify the deficits. However, recently developmental neuroscience literature has moved in a new direction. Functional magnetic resonance imaging (fMRI) studies have become remarkably sophisticated. Furthermore, last year President Obama announced funding for Advancing Innovative Neurotechnologies Initiative (BRAIN). This large scale project is expected to speed up the mapping of neural circuitry to identify how the brain actually works. The Allen Institute for Brain Science in Seattle has recently published The BrainSpan Atlas, a comprehensive three dimensional atlas of the developing human brain which is one of the first publications from the BRAIN initiative (Miller et al., 2014). The atlas is freely available to the public and provides beginning answers to when and how genes are turned on and off during development as well as anatomy of the brain during gestation and childhood. Themes in the recent neurodevelopmental literature about adolescents include the following: 1) Normal brain development progresses from bottom (brain stem) up (cerebral cortex), 2) during adolescence there is increased myelination and connectivity, 3) during adolescence there is increased specialization of neural pathways with pruning of unused pathways, 4) reconstruction of the cortex allows the beginning of conceptual thinking and creative exploration during adolescence, 5) increased dopamine drive allows for situational and comparative optimism resulting in risk taking, 6) the adolescent brain is vulnerable to developmental dysfunction due to a wide range of causes which are unmasked during pruning, and 7) brain plasticity facilitates psychotherapeutic change. RECONSTRUCTION OF THE CORTEX As the cortex of the brain is undergoing pruning and myelination, there is basically a reconstruction of all parts of the cortex. The frontal areas are responsible for the ability to be aware of ourselves and to begin to think in conceptual and abstract ways. Adolescents begin to consciously and creatively consider the meaning of life, friendships, family, school and in general everything. Adolescents begin to think about who they are and begin to develop a sense of identity. Although genetic makeup determines some of the timing of this ability, experiences also strongly influence these abilities. For example, adolescents who do not spend time in reflective thinking and conversations, may only minimally expand self-awareness. How an adolescent Corresponding Author: Dr. Kathleen R. Tusaie, PhD, APRN-BC. E-mail address: [email protected]. http://dx.doi.org/10.1016/j.apnu.2014.05.007 0883-9417/© 2014 Elsevier Inc. All rights reserved.
spends their time directly influences the neural pathways that are strengthened in a “use it or lose it” process. As adolescents become more reflective, there is an increase in narcissism and a drive to be with others who think in a similar manner. This is a time of adults being pushed to the background and friends becoming more important. The family becomes a safe harbor as well as a launching pad. This increasing interest in peers is a necessary step in human development. Adolescents need to interact and listen to peers in order to become part of that vital group as adolescents prepare to leave their nuclear families. DOPAMINE DRIVE FOR REWARD Adolescents have an increased tendency to make risky decisions. The literature acknowledges the complexity involved in understanding this risk-taking behavior and draws from cognitive, developmental, social, emotional, and neuroscience studies (Albert & Steinberg, 2013). But focusing on neurodevelopment, the prefrontal cortex is the last portion of the brain to develop, so the areas below such as limbic and brainstem are more active in adolescents than in adults or children (Carlisi, Pavletic, & Ernst, 2013). This suggests that emotional arousal in the adolescent brain is more potent than in adults. In other words, without the calming influence of the cortex, bursts of strong emotion can suddenly emerge. This is referred to as fight, flight or freeze reactions and accounts for moodiness. Furthermore, adolescents' have a hyperreactive reward system (nucleus accumbens, ventral prefrontal cortex, amygdala) as increased dopamine and a hyposensitive avoidant system (hippocampus, medial prefrontal cortex). This neurology results in situational and comparative optimism (Tusaie & Patterson, 2006). Situational optimism results in believing that the situation will not have any bad consequences or a positive bias. Comparative optimism is simply the belief that “it won’t happen to me”. This decreased fear, greater interest in novelty, and impulsivity serve a purpose across species. This stage of neural development most likely propels young birds from their nests and human teenagers into college dorms. Risk alters rigid ways of thinking and is necessary for courage, creativity, and adaptive behavior (Natterson-Horowitz & Bowers, 2013). VULNERABILITIES The adolescent brain has been reported to be more reactive to social and physiological influences than the child or adult. The influence of negative life events during adolescence have been demonstrated to have more reactions in the amygdala, greater changes in vital signs, and more hormonal release than adults (Ganzel, Kim, Gilmore, Tollerham, & Temple,
296
K.R. Tusaie / Archives of Psychiatric Nursing 28 (2014) 295–296
2013; Whittle et al., 2013). Furthermore, there is a rise in newly intense experiences such as rage, fear, aggression, excitement and sexual attraction. Another hormone, oxytocin, the bonding hormone, is increased, and the over sensitive limbic system of the adolescent leads to feelings of self-consciousness. This over reactivity results not only in more disruptive reactions to stress but also a more lengthy recovery time to restore balance. With the potential for overreactivity, a physiological influence such as lack of adequate sleep is a significant problem for adolescents. Melantonin, the chemical secreted by the pineal gland and responsible for shutting the body down for sleep, is very slowly released in the adolescent brain. Thus adolescents have more difficulty falling asleep at night. Combining this with the overuse of computer screens at night and very busy schedules, it becomes evident why adolescents are chronically fatigued. The use of recreational drugs by adolescents is driven by at least four fundamental drives. These are experimentation, social connection, selfmedication, and addiction. As previously discussed, the base line level of dopamine in an adolescent brain is lower than adults. Many recreational drugs influence the dopamine system and therefore are attractive to adolescents who may be feeling bored or dull. The common use of these substances by a peer group is often a way to connect and fit in and may also become a “social lubricant”. The changing adolescent brain is especially sensitive to becoming addicted. This addiction has many social and behavioral consequences which can negatively influence adolescent development as well as continue into adulthood. Another danger of using recreational drugs is the activation of a cascade of genes which may lead to mental illness. Recent studies have identified the use of marijuana in vulnerable adolescents as the trigger to the onset of schizophrenia (Raver, Haughwout, & Keller, 2013). The high plasticity of the adolescent brain allows for social and environmental influences to exert powerful influences upon neural circuits. While this is necessary for emotional and intellectual development, it also creates the possibility of harmful influences that may have lifelong implications (Konrad, Firk, & Uhlaas, 2013). Furthermore, neuroscience literature is beginning to move beyond description to associations and predictions. Researchers in United States as well as Europe have identified brain changes that may predict teen binge drinking, future cognitive development, bipolar and schizophrenic disorders (Sequeglia, Pulido, Wetherell, Jacobs, Brown, & Tapert, 2012; Ullman, Klingberg, & Almeida, 2014). In the other direction of behavior influencing brain development, the negative influence of cigarette and marijuana smoking upon adolescent brains has been reported with fMRI imaging (Morales, Ghahremone, Kohno, Hellerman, & London, 2014). Of course, there remains many mysteries yet to be uncovered related to the human brain. IMPLICATIONS Commonly used therapeutic approaches with adolescents including therapeutic relationship building, motivational interviewing, cognitive– behavioral techniques and mindfulness-based strategies are all supported by neurodevelopmental data (Wetherill & Tapert, 2013). However, the concept of “mature” minors and informed consent” must be reexamined in light of adolescent brain development information. Although, common developmental pathways have been identified, not all adolescents are the same. There is gender as well as
environmental and genetic differences. All adolescents are vulnerable, but some are more vulnerable than others. In addition to the brain plasticity concept, it is also important to remember that brains are social. There is a bidirectional effect between environment and neurology which points to a need for individual approaches. Furthermore, all humans are part of a boundless, infinitely elaborate community of minds that cannot be reduced to only neurons. This literature review has produced confirming as well as challenging information to consider when working with adolescents. Of course, at the core of working with adolescents is the examination of one's own assumptions. The ability to recognize that adolescence is not merely “an unfinished brain”, but an important developmental phase that is vital for development of the individual as well as the future of the human species. An ability to be present with the adolescent and the process of becoming, through many unpredictable experiences, is vital. The emotional spark and passion of adolescence due to a very active limbic system and hypoactive active prefrontal cortex can lead to a full life but can also be quite exhausting as health care providers bear witness. The importance of novelty seeking and social engagement may be exhilarating, but requires a balance with the discipline to finish a project and pay attention in school. Psychotherapy and positive life experiences hold the potential to increase logical thinking and decrease reactivity through increasing neural connectivity from the prefrontal cortex to the limbic system. This tension and turmoil of adolescent development can be influenced by many factors within and outside of the adolescent due to brain plasticity and the bidirectional influence of neurology and environment. References Albert, D., & Steinberg, L. (2013). Judgment and decision making in adolescence. Journal of Research on Adolescents, 21(1), 211–224. Carlisi, C. O., Pavletic, N., & Ernst, M. (2013). New perspectives on neural system models of adolescent behavior. Neuropsychiatric de l’enfance et de l’ adolescence, 61, 209–218. Ganzel, Kim, Gilmore, Tollerham, & Temple (2013). Stress and the healthy adolescent brain: Evidence for the neural embedding of life events. Development and Psychopathology, 25, 879–889. Konrad, K., Firk, C., & Uhlaas, P. (2013). Brain development during adolescence. Deutsches Ärzteblatt international, 110(25), 425–431 http://dx.doi.org/10.3238/ arztebl2013.0425. Miller, J. A., Ding, S. L., Sunkin, S. M., Smith, K. A., Ng, I., Szafer, A., et al. (2014). Transcriptional landscape of the prenatal brain. Nature, 2 http://dx.doi.org/10. 1038/nature13185. Morales, A., Ghahremone, D., Kohno, M., Hellerman, G., & London, E. (2014). Neuropsychopharmacology http://dx.doi.org/10.10388/npp.2014.48. Natterson-Horowitz, & Bowers (2013). Zoobiquity Ny: Alfred Knopf. Raver, S., Haughwout, S., & Keller, A. (2013). Adolescent cannabinoid exposure permanently suppresses cortical oscillations. Neuropsychopharmacology http://dx. doi.org/10.1038/npp.2013. Squeglia, L., Pulido, C., Wetherell, R., Jacobs, G., Brown, G., & Tapert, S. (2012). Brain response to working memory over three years of adolescence influence of heavy drinking. Journal of Studies on Alcohol and Drugs, 73, 749–760. Tusaie, K., & Patterson, K. (2006). Relationships among trait, situational, and comparative optimism: Clarifying concepts for a theory and evidence-based intervention to maximize resilience. Archives of Psychiatric Nursing, 20(3), 144–150. Ullman, H., Klingberg, T., & Almeida, R. (2014). Brain imaging may help predict future cognitive ability in children and adolescents. Journal of Neuroscience, 34(5), 1592–1598. Wetherill, R., & Tapert, S. (2013). Adolescent brain development, substance use, and psychotherapeutic change. Psychology of Addictive Behaviors, 27(2), 393–402. Whittle, S., Dennison, M., Vijayakunar, N., Simmons, J., Lubman, D., …, et al. (2013). Childhood maltreatment and psychopathology affect brain development during adolescence. Journal of the American Academy of Child and Adolescent Psychiatry, 52(9), 940–952.
Contents lists available at ScienceDirect
Archives of Psychiatric Nursing journal homepage: www.elsevier.com/locate/apnu
Child & Adolescent Mental Health Section
The Adolescent Brain: An Overview of Recent Research Kathleen R. Tusaie Univ of Akron
The past method of studying brain function has been to study those who have had some type of pathological brain damage and then identify the deficits. However, recently developmental neuroscience literature has moved in a new direction. Functional magnetic resonance imaging (fMRI) studies have become remarkably sophisticated. Furthermore, last year President Obama announced funding for Advancing Innovative Neurotechnologies Initiative (BRAIN). This large scale project is expected to speed up the mapping of neural circuitry to identify how the brain actually works. The Allen Institute for Brain Science in Seattle has recently published The BrainSpan Atlas, a comprehensive three dimensional atlas of the developing human brain which is one of the first publications from the BRAIN initiative (Miller et al., 2014). The atlas is freely available to the public and provides beginning answers to when and how genes are turned on and off during development as well as anatomy of the brain during gestation and childhood. Themes in the recent neurodevelopmental literature about adolescents include the following: 1) Normal brain development progresses from bottom (brain stem) up (cerebral cortex), 2) during adolescence there is increased myelination and connectivity, 3) during adolescence there is increased specialization of neural pathways with pruning of unused pathways, 4) reconstruction of the cortex allows the beginning of conceptual thinking and creative exploration during adolescence, 5) increased dopamine drive allows for situational and comparative optimism resulting in risk taking, 6) the adolescent brain is vulnerable to developmental dysfunction due to a wide range of causes which are unmasked during pruning, and 7) brain plasticity facilitates psychotherapeutic change. RECONSTRUCTION OF THE CORTEX As the cortex of the brain is undergoing pruning and myelination, there is basically a reconstruction of all parts of the cortex. The frontal areas are responsible for the ability to be aware of ourselves and to begin to think in conceptual and abstract ways. Adolescents begin to consciously and creatively consider the meaning of life, friendships, family, school and in general everything. Adolescents begin to think about who they are and begin to develop a sense of identity. Although genetic makeup determines some of the timing of this ability, experiences also strongly influence these abilities. For example, adolescents who do not spend time in reflective thinking and conversations, may only minimally expand self-awareness. How an adolescent Corresponding Author: Dr. Kathleen R. Tusaie, PhD, APRN-BC. E-mail address: [email protected]. http://dx.doi.org/10.1016/j.apnu.2014.05.007 0883-9417/© 2014 Elsevier Inc. All rights reserved.
spends their time directly influences the neural pathways that are strengthened in a “use it or lose it” process. As adolescents become more reflective, there is an increase in narcissism and a drive to be with others who think in a similar manner. This is a time of adults being pushed to the background and friends becoming more important. The family becomes a safe harbor as well as a launching pad. This increasing interest in peers is a necessary step in human development. Adolescents need to interact and listen to peers in order to become part of that vital group as adolescents prepare to leave their nuclear families. DOPAMINE DRIVE FOR REWARD Adolescents have an increased tendency to make risky decisions. The literature acknowledges the complexity involved in understanding this risk-taking behavior and draws from cognitive, developmental, social, emotional, and neuroscience studies (Albert & Steinberg, 2013). But focusing on neurodevelopment, the prefrontal cortex is the last portion of the brain to develop, so the areas below such as limbic and brainstem are more active in adolescents than in adults or children (Carlisi, Pavletic, & Ernst, 2013). This suggests that emotional arousal in the adolescent brain is more potent than in adults. In other words, without the calming influence of the cortex, bursts of strong emotion can suddenly emerge. This is referred to as fight, flight or freeze reactions and accounts for moodiness. Furthermore, adolescents' have a hyperreactive reward system (nucleus accumbens, ventral prefrontal cortex, amygdala) as increased dopamine and a hyposensitive avoidant system (hippocampus, medial prefrontal cortex). This neurology results in situational and comparative optimism (Tusaie & Patterson, 2006). Situational optimism results in believing that the situation will not have any bad consequences or a positive bias. Comparative optimism is simply the belief that “it won’t happen to me”. This decreased fear, greater interest in novelty, and impulsivity serve a purpose across species. This stage of neural development most likely propels young birds from their nests and human teenagers into college dorms. Risk alters rigid ways of thinking and is necessary for courage, creativity, and adaptive behavior (Natterson-Horowitz & Bowers, 2013). VULNERABILITIES The adolescent brain has been reported to be more reactive to social and physiological influences than the child or adult. The influence of negative life events during adolescence have been demonstrated to have more reactions in the amygdala, greater changes in vital signs, and more hormonal release than adults (Ganzel, Kim, Gilmore, Tollerham, & Temple,
296
K.R. Tusaie / Archives of Psychiatric Nursing 28 (2014) 295–296
2013; Whittle et al., 2013). Furthermore, there is a rise in newly intense experiences such as rage, fear, aggression, excitement and sexual attraction. Another hormone, oxytocin, the bonding hormone, is increased, and the over sensitive limbic system of the adolescent leads to feelings of self-consciousness. This over reactivity results not only in more disruptive reactions to stress but also a more lengthy recovery time to restore balance. With the potential for overreactivity, a physiological influence such as lack of adequate sleep is a significant problem for adolescents. Melantonin, the chemical secreted by the pineal gland and responsible for shutting the body down for sleep, is very slowly released in the adolescent brain. Thus adolescents have more difficulty falling asleep at night. Combining this with the overuse of computer screens at night and very busy schedules, it becomes evident why adolescents are chronically fatigued. The use of recreational drugs by adolescents is driven by at least four fundamental drives. These are experimentation, social connection, selfmedication, and addiction. As previously discussed, the base line level of dopamine in an adolescent brain is lower than adults. Many recreational drugs influence the dopamine system and therefore are attractive to adolescents who may be feeling bored or dull. The common use of these substances by a peer group is often a way to connect and fit in and may also become a “social lubricant”. The changing adolescent brain is especially sensitive to becoming addicted. This addiction has many social and behavioral consequences which can negatively influence adolescent development as well as continue into adulthood. Another danger of using recreational drugs is the activation of a cascade of genes which may lead to mental illness. Recent studies have identified the use of marijuana in vulnerable adolescents as the trigger to the onset of schizophrenia (Raver, Haughwout, & Keller, 2013). The high plasticity of the adolescent brain allows for social and environmental influences to exert powerful influences upon neural circuits. While this is necessary for emotional and intellectual development, it also creates the possibility of harmful influences that may have lifelong implications (Konrad, Firk, & Uhlaas, 2013). Furthermore, neuroscience literature is beginning to move beyond description to associations and predictions. Researchers in United States as well as Europe have identified brain changes that may predict teen binge drinking, future cognitive development, bipolar and schizophrenic disorders (Sequeglia, Pulido, Wetherell, Jacobs, Brown, & Tapert, 2012; Ullman, Klingberg, & Almeida, 2014). In the other direction of behavior influencing brain development, the negative influence of cigarette and marijuana smoking upon adolescent brains has been reported with fMRI imaging (Morales, Ghahremone, Kohno, Hellerman, & London, 2014). Of course, there remains many mysteries yet to be uncovered related to the human brain. IMPLICATIONS Commonly used therapeutic approaches with adolescents including therapeutic relationship building, motivational interviewing, cognitive– behavioral techniques and mindfulness-based strategies are all supported by neurodevelopmental data (Wetherill & Tapert, 2013). However, the concept of “mature” minors and informed consent” must be reexamined in light of adolescent brain development information. Although, common developmental pathways have been identified, not all adolescents are the same. There is gender as well as
environmental and genetic differences. All adolescents are vulnerable, but some are more vulnerable than others. In addition to the brain plasticity concept, it is also important to remember that brains are social. There is a bidirectional effect between environment and neurology which points to a need for individual approaches. Furthermore, all humans are part of a boundless, infinitely elaborate community of minds that cannot be reduced to only neurons. This literature review has produced confirming as well as challenging information to consider when working with adolescents. Of course, at the core of working with adolescents is the examination of one's own assumptions. The ability to recognize that adolescence is not merely “an unfinished brain”, but an important developmental phase that is vital for development of the individual as well as the future of the human species. An ability to be present with the adolescent and the process of becoming, through many unpredictable experiences, is vital. The emotional spark and passion of adolescence due to a very active limbic system and hypoactive active prefrontal cortex can lead to a full life but can also be quite exhausting as health care providers bear witness. The importance of novelty seeking and social engagement may be exhilarating, but requires a balance with the discipline to finish a project and pay attention in school. Psychotherapy and positive life experiences hold the potential to increase logical thinking and decrease reactivity through increasing neural connectivity from the prefrontal cortex to the limbic system. This tension and turmoil of adolescent development can be influenced by many factors within and outside of the adolescent due to brain plasticity and the bidirectional influence of neurology and environment. References Albert, D., & Steinberg, L. (2013). Judgment and decision making in adolescence. Journal of Research on Adolescents, 21(1), 211–224. Carlisi, C. O., Pavletic, N., & Ernst, M. (2013). New perspectives on neural system models of adolescent behavior. Neuropsychiatric de l’enfance et de l’ adolescence, 61, 209–218. Ganzel, Kim, Gilmore, Tollerham, & Temple (2013). Stress and the healthy adolescent brain: Evidence for the neural embedding of life events. Development and Psychopathology, 25, 879–889. Konrad, K., Firk, C., & Uhlaas, P. (2013). Brain development during adolescence. Deutsches Ärzteblatt international, 110(25), 425–431 http://dx.doi.org/10.3238/ arztebl2013.0425. Miller, J. A., Ding, S. L., Sunkin, S. M., Smith, K. A., Ng, I., Szafer, A., et al. (2014). Transcriptional landscape of the prenatal brain. Nature, 2 http://dx.doi.org/10. 1038/nature13185. Morales, A., Ghahremone, D., Kohno, M., Hellerman, G., & London, E. (2014). Neuropsychopharmacology http://dx.doi.org/10.10388/npp.2014.48. Natterson-Horowitz, & Bowers (2013). Zoobiquity Ny: Alfred Knopf. Raver, S., Haughwout, S., & Keller, A. (2013). Adolescent cannabinoid exposure permanently suppresses cortical oscillations. Neuropsychopharmacology http://dx. doi.org/10.1038/npp.2013. Squeglia, L., Pulido, C., Wetherell, R., Jacobs, G., Brown, G., & Tapert, S. (2012). Brain response to working memory over three years of adolescence influence of heavy drinking. Journal of Studies on Alcohol and Drugs, 73, 749–760. Tusaie, K., & Patterson, K. (2006). Relationships among trait, situational, and comparative optimism: Clarifying concepts for a theory and evidence-based intervention to maximize resilience. Archives of Psychiatric Nursing, 20(3), 144–150. Ullman, H., Klingberg, T., & Almeida, R. (2014). Brain imaging may help predict future cognitive ability in children and adolescents. Journal of Neuroscience, 34(5), 1592–1598. Wetherill, R., & Tapert, S. (2013). Adolescent brain development, substance use, and psychotherapeutic change. Psychology of Addictive Behaviors, 27(2), 393–402. Whittle, S., Dennison, M., Vijayakunar, N., Simmons, J., Lubman, D., …, et al. (2013). Childhood maltreatment and psychopathology affect brain development during adolescence. Journal of the American Academy of Child and Adolescent Psychiatry, 52(9), 940–952.
