Auditory event-related potential indices of increased distractibility in children with major depression

Objective: Children with major depression (MD) exhibit short-term memory and concentration deficits. Using auditory event-related potentials (ERPs), we aimed to determine whether these problems could be caused by a dysfunction in auditory sensory memory, attentional orienting, or both. Methods: The subjects were 10 treatment-naïve children with MD and 10 controls. Sound sequences, consisting of frequent stimuli (syllable /ka/, P=0.08), infrequent deviant stimuli (/ta/, P=0.01), and novel sounds (P=0.01) were played through loudspeakers while the children watched silent videos and ignored the sound stimuli. Auditory sensory memory was studied by eliciting the ERPs mismatch negativity (MMN) and late discriminative negativity (LDN), and the P3a was used as an index of involuntary attention switch. Results: The children with MD had shorter MMN and LDN latencies than the controls. The late component of the P3a (lP3a) was enhanced in amplitude in the patients as compared with that in the controls. Conclusions: Auditory sensory memory appears to function normally in children with MD. However, the ERP findings indicated enhanced sensory sensitivity and attentional distractibility in these children. This increased distractibility might underlie the concentration difficulties that compromise school performance in children with MD.