Developmental Theories and
RUNE J. SIMEONSSON
SUSAN L. ROSENTHAL
Age is usually not a central issue in the provision of psychological services to adults. However, every facet of clinical work with children is influenced by developmental factors. Presenting problems, the nature of assessment, types of diagnoses, and the implementation of interventions will vary significantly if the client is an infant, a preschooler, a school-age child, or an adolescent. The significance of developmental factors in clinical services is recognized by the fact that mental conditions that have their origin in infancy or childhood are assigned a separate section in DSM-IV (American Psychiatric Association [APA], 1994). Although DSM-IV yields a diagnostic classification for these conditions, it does not define causal factors or frame of treatment. For a comprehensive approach to the clinical activities of assessment, diagnosis, and intervention, it is essential that appropriate consideration is given to the child's age and stage of development. Such an approach can be enhanced by conceptual models that take into account change and continuity in the development of children.
The purpose of this chapter is to review selected models of child development in terms of their contribution to clinical practice. Conceptual frameworks are clearly important in guiding the clinician's approach to defining the problem and carrying out interventions. The formality and explicitness of conceptual frameworks may differ from one clinician to another, with some adhering to established theoretical models and others taking a more eclectic approach. Yet others may draw on subjective insights and personal experiences to address presenting problems. In the past, the provision of clinical services for children drew heavily on psychodynamic and learning models. Increasingly, there is a growing interest in the potential contribution of other models that can inform clinical interventions by taking developmental factors into account.
The field of developmental psychopathology (Luthar, Burack, Cicchetti, & Weisz, 1997) reflects the move toward comprehensive approaches in which developmental aspects of psychopathology in children and youth are considered. This field integrates cross-sectional and longitudinal findings on child development and draws on theories to guide clinical practice. Various models of development are available that could be of value in providing different perspectives on normal and atypical development. To be of value, such models should encompass variability in the nature and rate of development to account for individual differences in sensory, motor, cognitive, communicative, perceptual, and personal domains. Although the models do not directly lead to classification or to assignment of a diagnosis to