There is considerable evidence that children and adolescents with autistic spectrum disorders (ASD) are at increased risk of anxiety and anxiety disorders. However, it is less clear which of the specific DSM-IV anxiety disorders occur most in this population. The present study used meta-analytic techniques to help clarify this issue. A systematic review of the literature identified 31 studies involving 2,121 young people (aged <18 years) with ASD, and where the presence of anxiety disorder was assessed using standardized questionnaires or diagnostic interviews. Across studies, 39.6% of young people with ASD had at least one comorbid DSM-IV anxiety disorder, the most frequent being specific phobia (29.8%) followed by OCD (17.4%) and social anxiety disorder (16.6%). Associations were found between the specific anxiety disorders and ASD subtype, age, IQ, and assessment method (questionnaire versus interview). Implications for the identification and treatment of anxiety in young people with ASD are discussed.

The expression of two cytokines, granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin 3 (IL-3), has been investigated in MLA-144 cells before and after induction with phorbol 12-myristate 13-acetate. We describe an adaptation of the polymerase chain reaction (PCR) for highly accurate quantitation of mRNA or DNA from a small number ofcells. Aliquots ofthe PCR mixture containing cDNA copies of the RNA to be assayed were added to serial dilutions of a competitor DNA fragment that differed from the cDNA of interest by having either a small intron or a mutated internal restriction enzyme site. Therefore, the same primers were used to coamplify the unknown and the competitor.

The Children's Revised Impact of Event Scale (CRIES) is a brief childfriendly measure designed to screen children at risk for Posttraumatic Stress Disorder (PTSD). It has good face and construct validity, a stable factor structure, correlates well with other indices of distress, and has been used to screen very large samples of at-risk-children following a wide range of traumatic events. However, few studies have examined the scale's validity against a structured diagnostic interview based on the DSM-IV criteria for PTSD. In the present study, the CRIES and the PTSD section of the Anxiety Disorders Interview Schedule-Child and Parent Version (ADIS-CP) were administered to a sample of children and adolescents (n=63) recruited from hospital accident and emergency rooms and the validity of the CRIES as a screening tool evaluated. Cutoff scores were chosen from this sample with a low base-rate of PTSD (11.1%) to maximise sensitivity and minimise the likelihood that children with a diagnosis of PTSD would fail to be identified. Cutoff scores were then crossvalidated in a sample of 52 clinically referred children who had a high base-rate of PTSD (67.3%). A cutoff score of 30 on the CRIES-13 and a cutoff score of 17 on the CRIES-8 maximised sensitivity and specificity, minimized the rate of false negatives, and correctly classified 75-83% of the children in the two samples. The CRIES-8 (which lacks any arousal items) worked as efficiently as the CRIES-13 (which includes arousal items) in correctly classifying children with and without PTSD. Results are discussed in light of the current literature and of the need for further development of effective screens for children at-risk of developing PTSD.