Behavioral and emotional problems are highly prevalent in early childhood and represent an important focus of practice for clinical child and pediatric psychologists. Although psychological or psychiatric disorders are not typically diagnosed in children under the age of 2 years, recent research has demonstrated the appropriateness of assessing behavioral and emotional problems during the first 2 years of life (defined throughout as “infancy”). The current paper provides a systematic review of assessment procedures used to identify behavioral and emotional problems during infancy. Existing assessment procedures for infants take the form of parent- or caregiver-report questionnaires, observational coding procedures, and diagnostic classification systems. The questionnaires and observational coding procedures both had substantial psychometric evidence for use with infants, although observational coding may have limited utility in clinical practice. The classification systems have less empirical support for use with infants, and further research is necessary to demonstrate the appropriateness of these procedures with infants. Utilizing the reviewed procedures to assess behavioral and emotional problems in infants can have a substantial impact in research and practice settings, and further research is needed to determine the usefulness of these procedures in developing, testing, and implementing preventive and early intervention programs for infants and their families.

School-aged children with conduct problems and high levels of callous-unemotional (i.e., lack of empathy, guilt, and lack of caring behaviors) traits (CP+CU) tend to yield less benefit from traditional interventions than do their low-CU counterparts, particularly with respect to CP outcomes. To date, little is known about treatment response among young children with CP+CU, particularly those with or at risk for developmental delay. Components of Parent-Child Interaction Therapy (PCIT), a parent training program effective at reducing CP in young children, have compelling theoretical support for addressing core deficits unique to children with CP+CU and have been used successfully with young children with developmental delay. Our first aim was to test the psychometric properties of a measure of CU traits in preschool children with and without developmental delay. Our second aim was to test whether CU traits predicted post-treatment CP after controlling for initial levels of CP. Participants were 63 families of young children (mean age = 3.87 years), with or at-risk for developmental delay, who presented with elevated CP and were treated in a hospital-based outpatient clinic. Results indicated that developmentally delayed children with high levels of CU traits, but not children at-risk for delay due to premature birth, showed significantly poorer CP outcomes following treatment with PCIT than did children scoring low on CU traits, even after controlling for initial CP severity. The implications of these findings with regard to treating and preventing severe disruptive behaviors among young children with CP+CU are discussed.