Key clinical point: The specific insomnia complaint of difficulty initiating sleep was a significant independent predictor of first-onset major depressive disorder.

Major finding: First-onset depression was 2.3 times and 3.2 times more likely, respectively, among adults who reported trouble falling asleep 3-4 times a week or more than 4 times a week.

Study details: The data come from a prospective 6-year study of 768 adults in the Netherlands Study of Depression and Anxiety.

Disclosures: The study was supported by the European Research Council. The researchers had no financial conflicts to disclose.