Which disorder can begin in infancy and involves dysfunctional behaviors?

The correct answer is Autistic Disorder, which is a neurodevelopmental disorder that often manifests in early childhood, sometimes as early as infancy. Children with autistic disorder may exhibit a range of functional behaviors, including difficulties with social communication, repetitive patterns of behavior, and restricted interests. These symptoms can significantly impair their ability to interact with others and engage in typical activities of daily living.

In the context of the question, the emphasis on “dysfunctional behaviors” aligns closely with the characteristics of autistic disorder. These behaviors can manifest in various ways, such as a lack of social reciprocity, challenges in nonverbal communication, or obsessive interests. Early identification and intervention through music therapy can be beneficial in addressing these dysfunctions and supporting the child's development.

The other disorders mentioned typically do not have the same onset during infancy or are characterized differently. Dementia, for instance, is primarily associated with older adults and is characterized by cognitive decline rather than developmental behaviors. Communication disorders may occur early in life but do not encompass the broader range of dysfunctional behaviors seen in autistic disorder. Behavioral disorders can arise during childhood but are often associated with a range of causes, and not specifically linked to the early developmental markers like those seen in autistic disorder.