Development of Psychopathology: Nature and Nurture.

This book is organized into six chapters: 1. Fundamental Issues 2. Methods of Syndrome Analysis 3. Disorders of Motivation 4. Disorders of Action Regulation 5. Disorders of Language and Cognitive Development and 6. Conclusions. This is a bold and far-reaching book. Pennington raises fundamental issues on the nature and development of psychopathology. He articulates a fresh approach that is at once challenging yet informative and exciting, calculated to help advance the science of psychopathology. It should be required reading for all students of psychiatry, psychology and related disciplines. Pennington attempts an integrative multilevel approach in which he examines etiology, brain mechanisms, neuropsychology, and symptoms. In this way, he tries to show connections between these different levels of analysis. His argument is that we need a new framework or a paradigm to understand the development of psychopathology, and cognitive neuroscience provides this framework. He seeks to provide an underlying level of behavioral analysis that is closer to and more consistent with brain mechanisms than either symptom descriptions or purely psychological accounts. This approach directly challenges the latent dualism in much of psychology in which mental constructs are studied without consideration for how they are implemented by the brain. Chapter 2 describes methods of syndrome analysis that examines different levels of analysis. These include, epidemiology, behavioral and molecular genetics, neurobiology and neuropsychology. This chapter includes a detailed discussion that will be of interest to those wishing to be brought up to speed on the current ideas in these different areas. It serves as a framework for what follows. Chapters 3, 4 and 5 provide an overview and commentary on major syndromes in psychiatry. Each section follows a similar format. Pennington identifies and critiques the major theories of etiology for each of the syndromes he discusses and tries to show how these different areas relate to one another. He also summarizes treatment information identifying what is known and where there are deficiencies in our current treatment approaches. In his concluding chapter, Pennington stresses the importance of neuroscience in understanding psychopathology; he also resists reductionistic or dogmatic claims about the priority of a given level over others. He stresses the bidirectional nature of relations between levels and argues that this multilevel approach should attempt to integrate psychology with the rest of science. Work at these different levels should be mutually constraining. For example, although there are many branches of biology all are constrained by evolutionary theory. This principle of mutual constraint or conceptual integration is a powerful tool and can save time so that untenable theories do not see the light of day. His comments on the DSM are noteworthy. Behaviorally defined diagnoses are provisional and somewhat crude and there is accumulating evidence that diagnostic distinctions are misleading, such as the one between mood and anxiety disorders, for example. A goal of psychopathology research is to develop a classification system based on underlying causal processes to replace the current descriptive taxonomies. We need to understand psychopathology, at the level of pathogenesis or pathophysiology. There is insufficient evidence for the discriminate validity across disorders at the level of brain mechanisms. Many of the same neurotransmitters and brain structures play a major role in many disorders. Pennington tells us that all disorders appear to have multiple neurotransmitter and structural correlates. The hypothesis of a single cause for disorders at the level of the brain is not tenable. Likewise although a great deal is known about environmental correlates of psychopathology, it has been difficult to specify which environmental correlates are actually causal. Pennington reminds us that the etiology of a disorder does not necessarily dictate its treatment; psychosocial interventions can be very helpful for highly heritable disorders and medications can be beneficial for disorders whose etiology is mainly environmental. Pennington concludes that the neuroscience approach advocated in this book will increase scientific understanding on how psychopathology develops and will also lead to new advances in prevention and treatment. This book should be part of the library of every practitioner. It is not an easy read, and raises important questions and concepts that may challenge traditional ideas and well-worn attitudes. There are many pearls of wisdom, and it is embedded with rich, thoughtful and comprehensive ideas that on the one hand identifies our limited understanding and ignorance of psychopathology and its development, but on the other hand summarizes much that is known, integrates and critiques information from disparate sources, and at different levels in a way that is very seldom done. It offers fresh ways of thinking and offers us a promising direction to help guide future attempts to develop a comprehensive integrative theory of psychopathology. Pennington is to be applauded and congratulated for this excellent book.