Doctoral Defence in Psychology

Lada Zelinski will defend her doctoral thesis

Monday 23rd November, Lada Zelinski will defend her doctoral thesis in Psychology at the University of Akureyri. The doctoral thesis is entitled: Environmental and Individual Correlates of Depressive Symptoms in Iceland: The Role of Season, Environmental Mood Responses, and Circadian Preference.

The thesis can be found here (link will come here shortly)
The defence will be held in English in the University’s Ceremonial Hall in Akureyri at 10.00 and is open to the public
Please confirm your attendance here
The defence will be streamed here

The thesis work was supervised by Dr. Yvonne Höller, Professor in Psychology at the University of Akureyri, Dr. Arne C. Bathke, Professor in Statistics at the University of Salzburg in Austria and Dr. Ragnar P. Ólafsson, Professor in Psychology at the University of Iceland who served on the doctoral committee.

The opponents are Dr. Timo Partonen, Doctor of Medicine and Research Professor at Finnish Institute for Health and Welfare, Helsinki, Finland and Dr. Simon Nygaard Øverland, Professor and Director at the Centre for International Health at the University of Bergen in Norway.

Dr. Guðrún Rósa Þórsteinsdóttir Head of the Division of Research and Doctoral Studies and Dr. Mehmet Harma, Deputy Dean of the School of Humanities and Social Sciences will chair the ceremony.

About the Doctoral candidate

Born in Kazakhstan and raised in Germany, Lada Zelinski pursued her interest in human behaviour in the neighbouring Netherlands, earning a Bachelor's degree in Psychology from Radboud University in Nijmegen, followed by a Master's degree in Neuropsychology from Maastricht University. Her academic path then led her back to Germany, where she earned a second Master's degree in Interdisciplinary Neuroscience from Goethe University Frankfurt, deepening her interest in the neural mechanisms underlying human behaviour.

Lada started her doctoral studies at University of Akureyri in 2022, she moved to Iceland to join Yvonne Höller's research group and contribute to the EPiC SAD study, which investigates environmental, physiological and cognitive risk factors for Seasonal Affective Disorder, including its prevalence in Iceland. Her work within the project mainly involved epidemiological research and electroencephalography data collection. In her doctoral thesis, she examines how environmental conditions, together with individual differences in weather sensitivity, circadian preferences, and lifestyle behaviours, relate to depressive symptoms and how these associations vary throughout the year in Iceland.

During her PhD, Lada undertook several Erasmus+ research visits, including visits to the Lab for Sleep, Cognition & Consciousness in Salzburg, the Christian Doppler University Hospital in Salzburg, g.tec medical engineering GmbH in Schiedlberg, and Sapienza University of Rome.

Abstract

This dissertation examines environmental and individual correlates of depressive symptoms in Iceland, a high-latitude population characterised by extreme seasonal variation in daylight and rapid weather changes. Paper I combines self- report screening for seasonality with semi-structured diagnostic interviews in a nationally representative sample, finding weighted elevated seasonality of 17.86% but a diagnostically confirmed Seasonal Affective Disorder prevalence of only 2.24%. This pattern of decline is comparable to that reported in interview- confirmed studies from lower-latitude populations, suggesting that screening instruments alone may inflate apparent latitude effects. Paper II examines subjective mood responses to environmental conditions, objective meteorological variables, and their interaction as correlates of depressive symptom severity, showing that more adverse mood responses to cold weather and reduced daylight are associated with greater symptom severity and that the association between temperature and depressive symptoms depends on individuals' subjective sensitivity to cold. Paper III uses a longitudinal design spanning four seasons to examine circadian preference and energy drink consumption in relation to depressive and insomnia symptoms, finding that evening types report greater baseline symptom burden and that energy drink intake frequency is associated with depressive symptoms specifically during the transition from summer to autumn, particularly among evening types. Taken together, the three papers suggest that clinically diagnosable Seasonal Affective Disorder is comparatively rare, but that seasonal shifts in symptoms are common; that environmental influences on depressive symptoms depend on individual sensitivity rather than exposure alone; and that the relevance of behavioural risk factors, such as energy drink consumption, for depressive symptoms can depend on circadian preference and season. These findings indicate that the relationship between seasonal environmental conditions and depressive symptoms is not uniform across individuals. As climate change continues to alter environmental conditions, understanding these interactions will become increasingly relevant for identifying those most at risk and for developing targeted approaches to prevention and support.

All welcome!