Models of mental illness in children are a specific case of the general point Karl Popper made by defining the status of scientific theories as "nets cast to catch what we call 'the world.'" Seventy four years ago, the finest mesh explanatory net cast across the world of pediatric psychopathology was Leo Kanner's landmark text Child Psychiatry (1935), which defined for a generation of clinicians a pluralistic and avowedly anti-theoretical conception of its subject, illustrated by his 1973 observation that:
There are those who look on infantile sexuality alone, others on early mother-child relationship, others on faulty conditioning, still others on neuropathology or biochemistry alone as the open sesame to the gates of understanding and the passkey to therapeutic planning. What happens to a psychotic child and his family often has been 'programmed' not so much in accord with the specific circumstances of each patient's illness as by the predictable uniform ritualism of the approacher's orientation.
Kanner's sensitivity to his work's complexity -- his unwillingness to reduce his patients' intricate, multi-dimensional problems to one dimensional solutions -- is echoed in Beauchaine and Hinshaw's collection of 21 papers which endeavors to synthesize the genetic, environmental, neurological, cognitive and cultural variables of child and adolescent mental disorder in an integrated developmental psychopathological (DP) framework which eschews reductive notions of a singular "open sesame to the gates of understanding" for a multi-factorial, non-linear, dynamic systems approach. Adopting this sophisticated approach is no small task, Hinshaw concedes: "Smooth, packaged, easily digestible accounts are not found within these pages, as the kinds of reciprocal, interactive, cascading, and integrative models needed to facilitate further understanding are far from simple or linear." Digestibility aside, this 669 page text succeeds in providing an extremely cogent guide to leading-edge research in all the major child and adolescent mental disorders; the three innovative key principles that unite DP's interdisciplinary paradigm; and the potential shape of future research.
The first key feature of DP's non-linear approach is the concept of "multifinality": the idea (familiar from chaos theory) that a single set of conditions can lead to a wide array of possible outcomes, a principle vividly exemplified by Bruce D. Perry's paper on the catastrophic impact of abuse and maltreatment on "all of the major molecular processes involved in brain development." The negative neurological affects of abuse are so global in nature that almost any pathological outcome can flow from it, Perry shows. Maltreatment may thus be "the Great Imposter," the overlooked primary causal factor in a range of ostensibly diverse clinical profiles typically interpreted through the lens of differentiated DSM-IV diagnoses. Understanding the neurophysiological processes that drive abuse-related disease pathways could illuminate a diagnostic framework that more accurately depicts the underlying causal mechanisms of maltreatment's painful progression into pathology, Perry suggests.
DP's second key feature is the concept of "equifinality": the idea that the same pathological outcome can derive from multiple developmental pathways, a principle illustrated by Joel Nigg and Molly Nikolas' paper on Attention-Deficit/Hyperactivity Disorder (ADHD). The authors describe the disorder as a heterogeneous phenotype that stands on the extreme end of a continuously varying trait (rather than a uniform, discrete syndrome). Heritable features of the dopaminergic and noradrenergic systems, prenatal exposure to toxins, and family, social and cultural factors interact in recursive loops to produce disordered top-down (frontal-striatal) and bottom-up (frontal-limbic) neural circuits manifesting behaviorally in an array of comparable yet sub-phenotypically heterogeneous combinations of inattention and hyperactivity, often comorbid with anxiety disorders, Oppositional Defiant Disorder or Conduct Disorder, and learning disorders, Nigg and Nikolas report. Future research should adopt an integrated "person-centered" (rather than "variable-centered") approach to investigate the etiologies of specific sub-phenotypes to aid the prevention and long-term treatment of ADHD, the authors recommend.
The third key feature of DP is its implicit refutation of the nature/nurture fallacy, a principle powerfully demonstrated, for instance, in Geraldine Dawson and Susan Faja's paper on Autism Spectrum Disorders (ASD). Much of the first 50 years of ASD-related debate after Kanner first used the term "autism" in 1943 fixated upon an either/or debate about Kanner's partial attribution of autism to uncaring primary caregivers ("refrigerator mothers"), even though Kanner himself explicitly framed parental influence as only one factor of a disorder that was also "innate" (Kanner 1963). From a DP perspective, by contrast, the task of locating the disorder's core impairments and neurological substrates in the face of autism's complex symptomology involves an integrated understanding of the interactions played between anomalies in 100 candidate genes and environmental factors in the developmental course of a child's capacity for socialization and attunement. The good news is that intensive parental and educational intervention can now boost the limited "social motivation" which is hypothesized to be associated with the autistic child's impaired cortical dopaminergic reward circuitry. Continued interdisciplinary dialog could yield increasingly sophisticated models of the complex gene-environment interactions that result in ASD risk processes, with profound implications for further improvements in treatment if supported by robust social policy, Dawson and Faja conclude.
While the retrospective act of sketching the evolution of the mind sciences in the seven decades from Kanner's Child Psychiatry to Beauchaine and Hinshaw's Child and Adolescent Psychopathology is easier than the speculative act of imagining the field's growth in the decades ahead, it is still tempting to imagine an historical path that will one day edge the field towards the type of granular predictive modeling of complex, non-linear systems currently achievable in the physical sciences -- such as climatology, for instance, a field in which supercomputers operating at 200 petaflops (200 quadrillion calculations per second) are now theoretically capable of supporting the creation of models that grid the planet's colossally complex weather patterns at a scale of a single kilometer: the size of a single cloud system. By analogy, perhaps an integrated synthesis of genetics, neuroscience, and cognitive and developmental psychology will some day yield a diagnostic "net" which could "catch the world" of human minds with an ultra-fine mesh wrought at the scale of a single person. Individually person-centered, predictive psychopathology backed by warp-speed computation remains science fiction for now. Yet such a refined future model, whose first blueprint is arguably outlined in this book, might really be the "open sesame to the gates of understanding."
© 2009 Jason Thompson
Jason Thompson teaches children with special needs in an Oakland public elementary school. He is studying for a MA in Special Education at San Francisco State University and a MA in Buddhist Studies at Sunderland University in the UK. He has a MA in English Literature from Oxford University. His research interests include developmental psychopathology, and the intersection of Buddhist thought with the western mind sciences. He has published journalism in the British and American media, and recently had a paper accepted for publication in "Philosophy, Psychiatry and Psychology."