Lithium and propranolol in aggression and self-injurious behavior in the mentally retarded.

The effect of antiaggressive agents on self-injurious behavior (SIB) was retrospectively assessed by studying the charts of mentally retarded individuals with both aggression and SIB who had been treated with either lithium (n = 11) or propranolol (n = 6). The frequency of these two behaviors was examined during the 3 months prior to starting medication and the first 3-month period at either a therapeutic blood level of lithium or at the individual patient's maximum dose of propranolol. The results support an equal reduction in both behaviors with either drug. This suggests that antiaggressive agents may be useful in SIB and raises the possibility that similar biochemical mechanisms may underlie both behaviors.