Children with communication disorders present with a range of comorbid conditions. Occasionally one of the comorbid conditions manifests so strongly that the primary condition goes unnoticed by the clinician. This tendency to overlook comorbid health problems in the presence of a disability is referred to as diagnostic overshadowing. This is a five-year follow up case study of a 9-year-old female child. The child was initially diagnosed to have Separation Anxiety Disorder (SAD), but during the course of follow up she began to exhibit features of pervasive developmental disorder-not otherwise specified (PDD-NOS). This case report throws light on the severity of SAD which overshadowed PDD-NOS. Importance of follow-up and the need for a multidisciplinary team to be sensitive to the phenomenon of diagnostic overshadowing is discussed.
