Treatment issues related to sleep and depression

In the management of depression, the role of sleep and sleep disturbances i s important for several reasons. The same neurotransmitter systems that reg ulate mood, interest, energy, and other functions that may be disturbed in depression also regulate sleep. Sleep disturbances may be responsive to tre atment with some antidepressants and may be worsened during treatment with other antidepressants. Serotonergic neurons play a critical role in modulat ing the onset and maintenance of sleep, and it is thought that insomnia in depression is caused by dysfunction of serotonergic systems. For a signific ant minority, SSRIs can have negative effects on sleep patterns resulting i n insomnia that requires concomitant sedatives or anxiolytics. By contrast, agents that block the serotonin type 2 (5-HT2) receptor have beneficial ef fects on depressive insomnia. For example, a recent 8-week study comparing the effects of nefazodone and fluoxetine on sleep disturbances in outpatien ts with nonpsychotic depression and insomnia found that fluoxetine was asso ciated with approximately a 30% increase in the number of nocturnal awakeni ngs whereas nefazodone was associated with about a 15% decrease, a net diff erence of 45%. Long-term studies must be conducted to determine whether sle ep benefits provided by the newer antidepressants will continue past the ac ute treatment phase.