Residents who are depressed or having suicidal thoughts may benefit from screening for obstructive sleep apnea, investigators suggest.

This may be true even for people who don’t fit the typical sleep apnea profile, which is a male who is overweight, snores and complains of daytime sleepiness, said W. Vaughn McCall, M.D.

McCall and his colleagues found undiscovered sleep apnea in a significant number of adult patients with major depressive disorder, insomnia and suicidal thoughts during a study that had excluded participants with sleep disorders. “We were completely caught by surprise that people did not fit the picture of what obstructive sleep apnea is supposed to look like,” he said in a statement.

Major depressive disorder is a top psychiatric disorder in seniors, and can become more difficult to treat with age. Obstructive sleep apnea is also known to be linked with depression. But depression improves in people who use continuous positive airway pressure treatment. CPAP therefore may be a worthwhile depression therapy in cases where sleep apnea is found, McCall suggested.

Knowing this, clinicians may want to add a test for sleep apnea to the list when looking for potential contributors to intractable depression, McCall said. The sleep apnea test is relatively simple and inexpensive, he concluded.