The developmental-structuralist approach to psychopathology in infants and young children involves studying adaptive and maladaptive patterns at each level of "experimental organization" from the early sensory, motor, and affective-thematic organizations to the later representational ones. Psychopathology may be related to defects or constrictions at each organizational level, including the representational or symbolic realm, without underlying vulnerabilities in earlier levels of organization, and may also involve the presumed "underbelly" of the personality, those central nervous system organizations that have to do with filtering and processing of perceptions and experience (the early sensory and affective-thematic organizations). The most severe psychopathologies, it will be suggested, occur where there are compromises in both the early sensory and affective-thematic and later representational organizations. Early limitations in "processing" animate or inanimate experiences may, in many instances, be highly specific and reversible rather than global. The early detection of sensory and affective-thematic organizational compromises, followed by approaches that facilitate phase-specific "essential experiences" through intact sensory pathways and the remediation of compromised ones, may provide a systematic base for possible preventive intervention approaches.