Developmental Psychobiology

It is increasingly recognized that events and experiences in childhood and infancy, and even in utero, can have medical consequences in later life. This is particularly true in psychiatry. Once the realm of Freud and his followers, the concept that early life experience can influence, if not cause, psychiatric problems in adulthood has recently been embraced by the antithesis of psychoanalysis, biological psychiatry. The embrace, still tentative, is strengthening as supporting evidence steadily accumulates. Animal studies have done much in this respect. Housing rats in solitary cages after weaning instead of in small groups results in the development of behavioral and physiological changes that bear substantial similarities to schizophrenia. The stress associated with frequent brief separations of neonatal rats from their mother can result in long-lasting “depressive” symptoms.

It is in the human experiments of social deprivation, often as a consequence of aggression between nations or between individuals, where we see more clearly the influence of developmental factors on mental health. Mednick and associates (1) have shown that there is an increase in psychotic disorders in those born a few months after war-induced starvation and after certain influenza epidemics. Chronic behavioral disturbances and metabolic deficits in several brain regions are consequences of the profound neglect experienced by children left in Romanian orphanages. Related are the findings of Nemeroff and colleagues (2), who showed how childhood sexual or physical abuse can result in adult depressive symptoms that are poorly responsive to current antidepressant pharmacotherapy. A neurobiological understanding of these effects of early neglect or abuse is emerging: excessive stress hormone responses can influence brain development by interfering with normal neuronal function.

This little book, part of volume 23 of the annual Review of Psychiatry, does not delve into all these issues, although it does go a long way toward providing an introduction to some interesting aspects of this developmental neurobiology. The first chapter, addressing the psychobiology of infant-mother attachment, is clearly relevant to the interaction between infant trauma and depression. The second covers a specific related process, that of facial recognition. This essay assesses face processing in normal and abnormal development (e.g., autism) and is followed by a useful review on the neurobiology of reading disability. The final two chapters take two disorders, Gilles de la Tourette’s syndrome and schizophrenia, and attempt to put them in a developmental perspective. This works well with Tourette’s syndrome, where the disorder is comprehensively reviewed and we are shown the substantial contribution made by modern imaging techniques. The final report on the neurobiology of schizophrenia is less comprehensive, concentrating on details of the authors’ own, admittedly important, postmortem studies but missing much of the breadth of previous chapters.

Throughout the book we are rightly reminded of the importance of genetic factors and their interaction with environmental influences on developmental processes. Had previous psychiatric genetic studies been more open to the potential influence of environmentally determined developmental factors, our understanding of the multifactorial etiology of major psychiatric diseases may well have progressed farther and faster.