Future directions in the management of insomnia.

Research on insomnia has provided a number of important new insights, but fundamental deficits in our understanding remain. In considering priorities for future research, 3 areas warrant immediate attention. First, a causal relationship between insomnia and the adverse outcomes seen in insomnia patients needs to be established. Second, currently available symptomatic therapies need to be optimized. Recent data suggest that some benzodiazepine receptor agonists produce their hypnotic effect without side effects that were presumed to be inherent to sedation. Understanding the neuropharmacology underlying this differential effect would allow substantial improvements in the risk-benefit ratio for these drugs. Finally, the mechanisms of insomnia need to be better understood. Several lines of evidence suggest that physiologic arousal is important to the clinical presentation of primary insomnia. It remains unclear, however, whether this activation is primary or secondary to the insomnia itself. If physiologic hyperarousal causes primary insomnia, it would provide new approaches to the management of this disorder.