In a phase 1 trial (NCT01253317) of insulin-like growth factor (IGF-1) involving nine subjects with classic RTT, the RSBQ and the Anxiety, Depression, and Mood Scale (ADAMS), a recently developed instrument for assessing these domains in individuals with intellectual disability [30–32], were administered in a pilot evaluation of IGF-1 efficacy. Here, IGF1 is linked to Anxiety.