Day-to-day associations between subjective sleep and affect in regard to future depression in a female population-based sample.

Background: Poor sleep is a risk factor for depression, but little is known about the underlying mechanisms.

Aims: Disentangling potential mechanisms by which sleep may be related to depression by zooming down to the 'micro-level' of within-person daily life patterns of subjective sleep and affect using the experience sampling method (ESM).

Method: A population-based twin sample consisting of 553 women underwent a 5-day baseline ESM protocol assessing subjective sleep and affect together with four follow-up assessments of depression.