Treatment Issues Related to Sleep and Depression

In the management of depression, the role of sleep and sleep disturbances is important for severalreasons. The same neurotransmitter systems that regulate mood, interest, energy, and other functionsthat may be disturbed in depression also regulate sleep. Sleep disturbances may be responsive to treatmentwith some antidepressants and may be worsened during treatment with other antidepressants.Serotonergic neurons play a critical role in modulating the onset and maintenance of sleep, and it isthought that insomnia in depression is caused by dysfunction of serotonergic systems. For a significantminority, SSRIs can have negative effects on sleep patterns resulting in insomnia that requiresconcomitant sedatives or anxiolytics. By contrast, agents that block the serotonin type 2 (5-HT₂) receptorhave beneficial effects on depressive insomnia. For example, a recent 8-week study comparingthe effects of nefazodone and fluoxetine on sleep disturbances in outpatients with nonpsychotic depressionand insomnia found that fluoxetine was associated with approximately a 30% increase in thenumber of nocturnal awakenings whereas nefazodone was associated with about a 15% decrease, anet difference of 45%. Long-term studies must be conducted to determine whether sleep benefits providedby the newer antidepressants will continue past the acute treatment phase.