While some developmental delays can be overcome through treatment, as in Declan's case, often the assessment of these delays can lead to the diagnosis of one of a range of Pervasive Developmental Disorders (PDDs), the most commonly known of which is autism. PDDs are often called Autism Spectrum Disorders because they are classified by the severity of the symptoms present. For example, autistic children have significant deficits in social interaction and communication and they tend to engage in repetitive behaviors such as rocking and stroking or tapping themselves. By comparison, children with Asperger's can use language much more effectively, although one symptom of Asperger's is a fixation on an object to the extent that the person speaks to others mainly about that object, regardless of social situation.
According to the National Institute of Mental Health, symptoms of PDDs can be detected in children as early as from birth to one year. In terms of assessment and treatment, doctors will generally refer to a child psychologist or psychiatrist if a PDD is suspected. Treatment can help alleviate symptoms of PDDs (for the child as well as the child's family), but as the term "pervasive" suggests, these disorders cannot be outgrown or cured.
Finally, a word on recognizing, testing, and treating sensory integration problems. The concept behind these problems has been around since the late 1970s, when occupational therapist A. Jane Ayres presented a theory unifying some children's highly exaggerated sensory responses—of touch, taste, sight, smell, and sound—under the term Sensory Integration Dysfunction (SID).
- A child with auditory defensiveness may cover his ears and throw a tantrum if his kindergarten class sings a song together.
- A child with tactile defensiveness may violently resist wearing shoes or may be agitated by the inside tags in her clothing.
Perhaps because SID has been largely studied and treated by occupational therapists rather than psychologists, and because its definitions are still being clarified, SID does not appear in the DSM-IV, the official manual of mental disorders. Diagnosis and treatment of SID, then, must usually be undertaken by an occupational therapist certified to administer the Sensory Integration and Praxis Tests (SIPT).
While not categorized as an Autism Spectrum Disorder, SID presents parents with the similar challenge of early detection and intervention—not because SID can be cured, but so that the child and his family know how best to minimize and adjust to the symptoms.