Research

Currently, we search for sleep traits in patients with various types of psychiatric disorders: schizophrenia, anxiety and mood disorders, and chronic fatigue. We want to assay the influence of sleep on the disease trajectories and define sleep microstructure characteristics by using sleep laboratory and neuroimaging studies. Our study is based on a hypothesis that sleep and circadian traits can be used for dissecting patients with psychiatric disorders into etiologically more uniform disease subclasses. Further, we hypothesize that these subclasses differ in their prognosis and response to treatment. 

This study was stimulated by our recent finding of robust, sleep-based clusters among patients with psychosis in a large SUPER study in Finland as a part of the international Stanley Global Neuropsychiatric Genomic Initiative. Of note, insomnia symptoms were highly correlated with quality of life, an observation which led us also to conduct a clinical trial to treat insomnia symptoms in schizophrenia. 

Find out more about our research on sleep and psychiatric disorders: 

A longitudinal cohort study evidencing for the causality between poor sleep quality and subsequent depressed mood (Paunio 2009) and depression (Paunio 2014) has constructed a baseline for Sleep and Health. Later, we showed deviating DNAme pattern among adolescents with depression and comorbid insomnia (Ämmälä 2019).  

We have explored genetic influences underlying schizophrenia and bipolar disorder in a national and international collaboration for more than two decades (see eg, Trubetskoy 2022, Singh 2022,  Sinha 2019, BPD-PGC and SZ-PRC 2019, Steinberg 2017, Peltola 2016, Marshall 2016, SWG-PGC 2014,  Stoll 2013). In an epidemiological sleep study of a cohort of ~10 000 individuals with major psychiatric illness from the large SUPER study in Finland as a part of the international Stanley Global Neuropsychiatric Genomic Initiative, we identified three sleep-based clusters among psychosis patients and discovered that symptoms of disturbed sleep associate robustly to subjective health and wellbeing (Cederlöf, Schizophrenia Bulletin Open, 2022 and 2023).  

(Current activity) 1) Analysis of the PSG data (n=40)and the effects of substance use, medication and genetic factors of theSUPER study is underway. 2) There is an RCT ongoing in patients with chronic schizophrenia and symptoms of insomnia, in which we are testing for the effect of the evidence-based treatment for insomnia (CBT-I) we developed for HUCH Mental.hub (registered, NCT04144231). 3) To evaluate the role of sleep and circadian rhythms in the disease course in early psychosis or anxiety disorder, we are monitoring sleep, circadian rhythms, cognition and emotion regulation in cases with early psychosis and anxiety disorder and controls in a longitudinal study. High-density wake and sleep EEG (hd-EEG) monitoring is being used to characterise oscillations related to cognitive performance. Responses to emotions evoked by different video clips are being monitored in a sleep laboratory and by fMRI. In addition, blood samples (plasma and blood cells) are being collected via the Helsinki Biobank for the analysis of genetic influences and the search for biomarkers. (LINK). 

In two parallel population-based birth cohorts, Child-Sleep and FinnBrain, we have explored the development of sleep and emotional regulation, as well as the underlying genetic mechanisms. Our findings emphasize the importance of sleep, and the interplay of sleep insufficiency with genetic risk factors, in the early development. Currently, we aim to identify EEG- based biomarkers of early life indicators for vulnerability to psychiatric diseases. 

Find out more about our research on sleep and psychiatric disorders: 

We explore the development of sleep and emotion regulation and the underlying genetic mechanisms in two parallel population-based birth cohorts from Finland: Child Sleep (Paavonen 2017) and FinnBrain (Karlsson 2017) (e.g. Acosta 2020,  Kiviruusu 2020,  Mäkelä 2020, Pietikäinen 2020, Sulkava 2020, Lempainen 2021, Mäkelä 2021, Pietikäinen 2021, Kajanoja 2022, Liuhanen 2023). We identified the link between genetic liability to a diurnal preference for eveningness and longer sleep-onset during the first two years of life (Morales-Munoz 2021) and the interaction of short sleep duration and genetic risk for ADHD at 5 yrs (Morales-Munoz, 2023). Our findings emphasize the importance of sleep in the development of mental functions, and the interplay of sleep insufficiency with the genetic risk for psychiatric disorders during early development.  

(Current activity) We are in the process of identifying EEG-based biomarkers of early life as indicators for vulnerability to psychiatric diseases (collaboration: Child-Sleep and FinnBrain study groups, prof. Sampsa Vanhatalo). Both birth cohorts are followed longitudinally, and our focus is to clarify the role of sleep traits as potential endophenotypes for psychiatric diseases.