NEW YORK: Persistent insomnia may perpetuate depression in elderly patients receiving standard care by primary care providers, according to study findings reported in the journal Sleep.

“This study highlights the importance of staying on top of insomnia that (occurs) with depression,” lead author Dr Wilfred R. Pigeon, from the University of Rochester Medical Centre in New York, said. “We don’t yet know which patients’ insomnia will dissipate when depression starts to improve, so the most conservative approach would be to treat it when you see it.”

Insomnia has historically been considered a symptom of depression, the authors note, and recent evidence suggests that insomnia is a risk factor for depression onset and recurrence.

Whether insomnia represents a separate disorder remains open to question.

To explore these issues, the researchers examined data from Project IMPACT, a study conducted at 18 primary care clinics comparing enhanced care with usual care for late-life depression. The group consisted of 1,801 patients, age 60 or older, with a diagnosis of severe or mild depression.

“In the usual-care group, physicians were free to treat patients as they chose,” Pigeon explained. “In the (enhanced care) group, patients received ‘stepped care’ by a nurse care manager, who provided...education about depression and brief ‘problem-focused therapy’. Depending on their progress, the nurse could suggest medication changes to the primary care provider or suggest and facilitate a referral to a psychiatrist if there was still no progress.”

Using standard diagnostic criteria, 293 subjects did not have insomnia, while 207 had persistent and 1,301 had intermediate insomnia.

Severe depression at six months remained in 44 per cent of the patients with persistent insomnia, 29 per cent of those with intermediate insomnia and 16 per cent of those without insomnia.

In a subgroup analysis comparing patients without insomnia to those with persistent insomnia, persistence was associated with statistically significant greater risk of sustained depression at 6 and 12 months.

The association was stronger in patients diagnosed with severe depression and among those receiving usual care.The findings do not “unequivocally tell us” if insomnia that accompanies depression is a symptom or a separate disorder, Pigeon’s group maintains.

The most likely scenario, they add, is that “insomnia is simply a symptom in some cases and clearly a disorder requiring its own treatment focus in other cases.”—Reuters