Internalizing problems - encompassing feelings of sadness, worry, irritability, and fear - are among the most prevalent psychiatric concerns throughout people’s lives. In youth, nearly one in three children experiences clinically significant anxiety, and one in four undergoes a depressive episode before reaching puberty (Merikangas et al., 2010). Left untreated, these issues can lead to a range of long-term consequences, including chronic depression, poor physical health, academic difficulties, substance abuse, and increased mortality from suicide (Bittner et al., 2007; Fergusson & Woodward, 2002; Pine et al., 1998). Moreover, anxiety and depression often co-occur, with up to 70% of treatment-seeking youth presenting with both disorders, leading to worsened outcomes (Garber & Weersing, 2010).

Research consistently supports the efficacy of transdiagnostic CBT approaches for youth. For example, BBT’s behavioral focus aligns with evidence demonstrating that exposure and behavioral activation are highly effective for treating anxiety and depression (Anderson et al., 2016; Newby et al., 2016). Additionally, studies have highlighted that shared intervention strategies for internalizing disorders can simplify treatment delivery while maintaining strong outcomes, as shown by comparable improvements in anxiety and depressive symptoms (García-Escalera et al., 2016; Ehrenreich-May et al., 2017).