Final answer:
Clinicians reflecting a developmental viewpoint assess clients by considering their unique personal history and context, consistent with developmental psychology's focus on changes over the lifespan. They use developmental theories and the explanatory model to inform their understanding and treatment plans.
Step-by-step explanation:
When clinicians assess a client's presenting problem(s) in order to plan for treatment, the approach that reflects a developmental viewpoint is the one that assesses the nature of the problem by considering the person's unique history, interpersonal context, and challenges in the extrapersonal environment. This approach is in line with developmental psychology, which emphasizes understanding how people change over time and is influenced by various developmental theories. Developmental psychologists use a variety of methods like case studies and analyses of developmental stages to gain insight into the physical and psychological changes that occur across a person's lifespan.
Major developmental theories, such as those proposed by Erik Erikson and Jean Piaget, aid in understanding the progression of changes throughout a person's life. They highlight the continuous or discontinuous nature of development, the variability in development patterns, and the interaction between genetics and environment (nature versus nurture). Psychologists also have to consider the explanatory model, which takes into account a client's personal beliefs and explanations for their condition, potentially aiding in the design of effective and culturally sensitive treatments.