Netherlands Institute for Neuroscience
Sleep & Cognition
VU University Amsterdam

Email Tessa Blanken
Phone: +31 20 5665492

On September 18, 2020, Tessa Blanken defended her thesis Changing perspectives on insomnia and depression: From symptoms to system, at the Vrije Universiteit Amsterdam.

Summary

Insomnia is the second-most prevalent disorder and a primary risk factor for depression. It has proven difficult, however, to pinpoint consistent characteristics of insomnia, suggesting unrecognized heterogeneity. In addition, considerable overlap in the symptoms of insomnia and depression raises questions on their empirically identified relationships: could the increased risk and their co-occurrence largely reflect this symptom overlap?

In a series of studies we aimed to unravel insomnia heterogeneity and disentangle the relationship between insomnia and depression. In a first large-scale, data-driven study we identified five insomnia subtypes, that were distinguished by their multivariate profile of life history, affect, and personality. Crucially, these subtypes differed up to a factor five in their risk of comorbid and lifetime depression.

We continued to investigate the role between insomnia and depression, while taking their overlap into account. To this end, we introduced two novel extensions to network analysis that allowed us to distinguish direct from indirect risk factors using Network Outcome Analysis; and direct from indirect treatment effects using Network Intervention Analysis. In a prospective study, specifically difficulty initiating sleep (DIS) increased the risk for first-onset depression, even after accounting for all other depression-related complaints. Using an intervention study we demonstrated that cognitive behavioral therapy for insomnia (CBTI) directly affected specifically difficulty maintaining sleep (DMS) and early morning awakenings (EMA), and that these changes preceded the observed alleviations in depression.

The identification of subtypes reduces previous unrecognized heterogeneity, which will facilitate the elucidation of mechanisms of insomnia, and the development and optimization of personalized treatments. Moreover, the identification of DIS and specific insomnia subtypes as primary risk factors for the development of depression now allows to select patients that run the highest risk, which opens up ways for the prevention of depression.

When prevention fails, people with concurrent depression and insomnia complaints can benefit from insomnia treatment targeting EMA and DIS. Together, these studies point towards the key role of specific insomnia symptoms in the development and treatment of depression, offering opportunities to combat the global burden of depression through prevention and intervention.

Supervisors
Prof. Eus van Someren &Prof. Denny Borsboom

Funder
ERC