Publications

Clara Wiebel, Veerle C. Eijsbroek, Vasudha Varadarajan, Katarina Kjell, H. Andrew Schwartz, Oscar Kjell (2026). Assessing the Need for Mental Health Support From Free-Text Responses: Development and Validation of Language-Based Assessments in Adults With Internalizing Symptoms. JMIR Mental Health, 13, e105460

Marc Sparhuber, Veerle Eijsbroek, Katarina Kjell, Salvatore Giorgi, Oscar Kjell (2026). Evidence of Limited Biases in Probed Language-based Assessments. PsyArXiv

Damon Navandi, Veerle C. Eijsbroek, Clara Wiebel, Aaron Marker, Katarina Kjell, Marc L. Molendijk, Elizabeth C. Stade, Oscar N.E. Kjell (2026). Clinicians' practices and attitudes toward depression assessment: a cross-sectional survey study. BMC Psychology, 14, 1227

Adithya V. Ganesan, Vasudha Varadarajan, Yash Kumar Lal, Veerle C. Eijsbroek, Katarina Kjell, Oscar N.E. Kjell, Tanuja Dhanasekaran, Elizabeth C. Stade, Johannes C. Eichstaedt, Ryan L. Boyd, H. Andrew Schwartz, Lucie Flek (2026). Explaining GPTs' schema of depression: A machine behavior analysis. Journal of Psychopathology and Clinical Science

Scott Feltman, Adithya V. Ganesan, Whitney Ringwald, H. Andrew Schwartz, Roman Kotov, Benjamin Luft, Ryan Boyd, Oscar Kjell (2026). Discriminant Validity: Disentangling Health and Emotional Constructs from Language-Based Assessments. Proceedings of the 11th Workshop on Computational Linguistics and Clinical Psychology (CLPsych 2026), 43–55

Adithya V. Ganesan, Vasudha Varadarajan, Oscar Kjell, Whitney R. Ringwald, Scott M. Feltman, Benjamin J. Luft, Roman Kotov, Ryan L. Boyd, H. Andrew Schwartz (2026). From Word Sequences to Behavioral Sequences: Adapting Modeling and Evaluation Paradigms for Longitudinal NLP. Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (ACL 2026), 47160–47179

Aaron Marker, Oscar Kjell, Vasudha Varadarajan, H. Andrew Schwartz (2026). Evaluating Document-Tuned Transformer Representations for Person-level Mental Health Assessment. Proceedings of the 11th Workshop on Computational Linguistics and Clinical Psychology (CLPsych 2026), 178–187

Oscar N.E. Kjell, Adithya V. Ganesan, Ryan L. Boyd, Joshua R. Oltmanns, Alfredo Rivero, Scott Feltman, Melissa A. Carr, Jorge Alves, Benjamin Luft, Roman Kotov, H. Andrew Schwartz (2026). Replicability and Validity of a New Artificial-Intelligence Assessment of Posttraumatic Stress Disorder From Patient Language: A Sequential Evaluation With Model Preregistration. Clinical Psychological Science

Veerle C. Eijsbroek, August Nilsson, Leon Ackermann, Zhuojun Gu, Clara Wiebel, Adithya V. Ganesan, Katarina Kjell, H. Andrew Schwartz, Oscar N.E. Kjell (2026). Multiple Methods for Visualizing Human Language: A Tutorial for Social and Behavioural Scientists. PsyArXiv

August Håkan Nilsson, Petri J. Kajonius, Oscar Kjell, Micael Dahlen, H. Andrew Schwartz, Brendan Case, Byron Johnson, Tim Lomas, Noah Padgett, Tyler J. VanderWeele (2026). Swedish Well-Being: The rising importance of age among demographic, personality, and social relationship factors. SSM – Population Health, 34, 101913

Oscar N.E. Kjell, Scott Feltman, H. Andrew Schwartz, Adithya V. Ganesan, Whitney R. Ringwald, Sean Clouston, Melissa A. Carr, Benjamin Luft, Roman Kotov (2026). Distinguishing the Language of Mental and Physical Health: A Sequential Evaluation with Model Preregistration of Automated Clinical Visit Interviews. PsyArXiv

Huy Vu, Huy Anh Nguyen, Adithya V. Ganesan, Swanie Juhng, Oscar N.E. Kjell, Joao Sedoc, Margaret L. Kern, Ryan L. Boyd, Lyle Ungar, H. Andrew Schwartz, Johannes C. Eichstaedt (2026). PsychAdapter: adapting LLMs to reflect traits, personality, and mental health. npj Artificial Intelligence, 2(1), 26

Panagiotis Kaliosis, Adithya V. Ganesan, Oscar N.E. Kjell, Whitney Ringwald, Scott Feltman, Melissa A. Carr, Dimitris Samaras, Camilo Ruggero, Benjamin J. Luft, Roman Kotov, H. Andrew Schwartz (2026). A Systematic Evaluation of Large Language Models for PTSD Severity Estimation: The Role of Contextual Knowledge and Modeling Strategies. arXiv:2602.06015

August H. Nilsson, Veerle C. Eijsbroek, Zhuojun Gu, Katarina Kjell, Salvatore Giorgi, Roman Kotov, Adithya V. Ganesan, H. Andrew Schwartz, Oscar N.E. Kjell (2026). The Language-Based Assessment Model (L-BAM) Library: Open Model Sharing for Independent Validation and Broader Applications. Advances in Methods and Practices in Psychological Science

Nora Bittár, August Håkan Nilsson, Micael Dahlen, Mirjam Nathanson, Petri J. Kajonius, Oscar Kjell, Tim Lomas, R. Noah Padgett, Brendan Case, Ying Chen, Richard G. Cowden, Byron R. Johnson, Tyler J. VanderWeele (2025). Flourishing in Sweden: Great overall—but not for all. International Journal of Wellbeing, 15(3)

Oskar Bång, Zhuojun Gu, August Nilsson, Veerle Eijsbroek, Clara Wiebel, Adithya V. Ganesan, Katarina Kjell, H. Andrew Schwartz, Oscar Kjell (2025). Language-Based Affect Assessments Capture Experiment-Induced Changes Beyond Rating Scales. PsyArXiv

Zhuojun Gu (2025). Developing and Validating Language-Based Assessments for Mental Health: Measuring and Describing Depression, Anxiety, Affect, and Suicidality and Self-Harm Risk, from Individuals' Own Descriptions. Doctoral thesis, Lund University (ISBN 978-91-8104-705-9)

Zhuojun Gu, Rajath Rao, August Håkan Nilsson, Veerle Eijsbroek, Oscar Kjell (2025). Extended Abstract: Probed Language-Based Assessments Using Spoken Language. 2025 IEEE International Professional Communication Conference (ProComm), 258–260

August Håkan Nilsson, J. Malte Runge, Adithya V. Ganesan, Carl Viggo N. G. Lövenstierne, Nikita Soni, Oscar Kjell (2025). Implicit Motives Codings are at Least as Accurate as Humans’ and 99% Faster. Journal of Personality and Social Psychology, 128(6)

Zhuojun Gu, Katarina Kjell, H. Andrew Schwartz, Oscar N.E. Kjell (2025). Natural Language Response Formats for Assessing Depression and Worry with Large Language Models: A Sequential Evaluation with Model Pre-registration. Comprehensive Psychiatry

Veerle C. Eijsbroek, Katarina Kjell, H. Andrew Schwartz, Jan R. Boehnke, Eiko I. Fried, Daniel N. Klein, Peik Gustafsson, Isabelle Augenstein, Patrick M.M. Bossuyt, Oscar N.E. Kjell (2025). The LEADING guideline: Reporting standards for expert panel, best-estimate diagnosis, and longitudinal expert all data (LEAD) methods. Comprehensive Psychiatry

Tim Lomas, August Håkan Nilsson, Oscar N.E. Kjell, Ryan Niemiec, James O. Pawelski, R. Noah Padgetta, Tyler J. VanderWeele (2024). Differentiating balance and harmony through natural language analysis: a cross-national exploration of two understudied wellbeing-related concepts. Journal of Positive Psychology

Rajath Rao, Adithya V Ganesan, Oscar Kjell, Jonah Luby, Akshay Raghavan, Scott Feltman, Whitney Ringwald, Ryan L. Boyd, Benjamin Luft, Camilo Ruggero, Neville Ryant, Roman Kotov, H. Andrew Schwartz (2024). WhiSPA: Semantically and Psychologically Aligned Whisper with Self-Supervised Contrastive and Student-Teacher Learning. Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics

August Nilsson, Ryan Boyd, Adithya V. Ganesan, Oscar N.E. Kjell, Syeda Mahwish, Haitao Huang, Richard N. Rosenthal, Lyle H. Ungar, H. Andrew Schwartz (2024). Language-based Assessments for Experienced Well-being: Accuracy and External Validity Across Behaviors, Traits, and States. PsyArXiv

Vasudha Varadarajan, Sverker Sikström, Oscar N.E. Kjell, H. Andrew Schwartz (2024). ALBA: Adaptive Language-Based Assessments for Mental Health. Proceedings of the 2024 Conference of the North American Chapter of the Association for Computational Linguistics (NAACL 2024), 2466–2478

August Håkan Nilsson, Johannes C. Eichstaedt, Tim Lomas, Andrew Schwartz, Oscar Kjell (2024). The Cantril Ladder elicits thoughts about power and wealth. Scientific Reports, 14(2642)

Oscar N.E. Kjell, Katarina Kjell, H. Andrew Schwartz (2023). Beyond Rating Scales: With targeted evaluation, large language models are poised for psychological assessment. Psychiatry Research, 333, 115667

Oscar Kjell, Salvatore Giorgi, H. Andrew Schwartz (2023). The Text-Package: An R-Package for Analyzing and Visualizing Human Language Using Natural Language Processing and Transformers. Psychological Methods

Sverker Sikström, Alfred Pålsson Höök, Oscar Kjell (2023). Precise language responses versus easy rating scales—Comparing respondents’ views with clinicians’ belief of the respondent’s views. PLOS ONE, 18(2)

Oscar Kjell, Salvatore Giorgi, H. Andrew Schwartz, Johannes C. Eichstaedt (2022). Towards Well-Being Measurement with Social Media Across Space, Time, and Cultures: Three Generations of Progress. World Happiness Report 2023

August Håkan Nilsson, Erik Hellryd, Oscar Kjell (2022). Doing well-being: Self-reported activities are related to subjective well-being. PLOS ONE

Oscar N. E. Kjell, Sverker Sikström, Katarina Kjell, H. Andrew Schwartz (2022). Natural language analyzed with AI‐based transformers predict traditional subjective well‐being measures approaching the theoretical upper limits in accuracy. Scientific Reports, 12(3918)

Paul T. P. Wong, Gökmen Arslan, Victoria L. Bowers, Edward J. Peacock, Oscar Nils Erik Kjell, Itai Ivtzan, Tim Lomas (2021). Self-Transcendence as a Buffer Against COVID-19 Suffering: The Development and Validation of the Self-Transcendence Measure-B. Frontiers in Psychology, 12(648549)

Sverker Sikström, Mats Dahl, Hannah Lettmann, Anna Alexandersson, Elena Schwörer, Lotta Stille, Oscar Kjell, Åse Innes-Ker, Leonard Ngaosuvan (2021). What you say and what I hear: Investigating differences in the perception of the severity of psychological and physical violence in intimate partner relationships. PLoS ONE

Katarina Kjell, Per Johnsson, Sverker Sikström (2021). Freely Generated Word Responses Analyzed With Artificial Intelligence Predict Self-Reported Symptoms of Depression, Anxiety, and Worry. Frontiers in Psychology

Kjell, Oscar, Daiva, Daukantaite, Sverker, Sikström (2020). Computational Language Assessments of Harmony in Life — Not Satisfaction With Life or Rating Scales — Correlate With Cooperative Behaviors. Journal of Example Studies

David Marcusson-Clavertz, Oscar N. E. Kjell, Jinhyuk Kim, Stefan D. Persson, Etzel Cardeña (2020). Sad Mood and Poor Sleep Are Related to Task-Unrelated Thoughts and Experience of Diminished Cognitive Control. Scientific Reports, 10(8940)

Oscar N. E. Kjell, Ed Diener (2020). Abbreviated Three-Item Versions of the Satisfaction with Life Scale and the Harmony in Life Scale Yield as Strong Psychometric Properties as the Original Scales. Journal of Personality Assessment

David Marcusson-Clavertz, Melina West, Oscar N. E. Kjell, Eli Somer (2019). A daily diary study on maladaptive daydreaming, mind wandering, and sleep disturbances: Examining within-person and between-persons relations. PLOS ONE, 14(11)

David Marcusson-Clavertz, Oscar N.E. Kjell, Stefan D. Persson, Etzel Cardeña (2019). Online validation of combined mood induction procedures. PLoS ONE, 14(6), e0217848

Katarina Kjell, Karolina Löwgren, Anders Rasmussen (2018). A Longer Interstimulus Interval Yields Better Learning in Adults and Young Adolescents. Frontiers in Behavioral Neuroscience, 12(299)

Oscar Kjell (2018). Conceptualizing and Measuring Well-Being Using Statistical Semantics and Numerical Rating Scales. Lund University Faculty of Social Sciences

David Marcusson-Clavertz, Oscar N. E. Kjell (2017). Psychometric Properties of the Spontaneous and Deliberate Mind Wandering Scales. European Journal of Psychological Assessment

Oscar N. E. Kjell, Katarina Kjell, Danilo Garcia, Sverker Sikström (2017). Semantic Measures: Using Natural Language Processing to Measure, Differentiate, and Describe Psychological Constructs. Psychological Methods

Itai Ivtzan, Tarli Young, Hoi Ching Lee, Tim Lomas, Daiva Daukantaitė, Oscar N. E. Kjell (2016). Mindfulness Based Flourishing Program: A Cross-Cultural Study of Hong Kong Chinese and British Participants. Journal of Happiness Studies, 18(6)

Danilo Garcia, Oscar NE Kjell, Sverker Sikström, Trevor Archer (2016). Using Language and Affective Profiles to Investigate Differences between Individuals. Clinical and Experimental Psychology, 2(2)

O. N. E. Kjell, D. Daukantaite, K. Hefferon, S. Sikström (2016). The Harmony in Life Scale Complements the Satisfaction with Life Scale. "Social Indicators Research, 126(3)"

Danilo Garcia, Oscar N.E. Kjell, Sverker Sikström (2015). A Collective Picture of What Makes People Happy: Words Representing Social Relationships, not Money, are Recurrent with the Word 'Happiness' in Online Newspapers. In G. Riva, B. K. Wiederhold & P. Cipresso (Eds.), The Psychology of Social Networking Vol. 2: Identity and Relationships in Online Communities (pp. 4–16). De Gruyter Open

Danilo Garcia, Henrik Anckarsäter, Oscar N. E. Kjell, Trevor Archer, Patricia Rosenberg, C. Robert Cloninger, Sverker Sikström (2015). Agentic, communal, and spiritual traits are related to the semantic representation of written narratives of positive and negative life events. Psychology of Well-Being, 5(8)

Danilo Garcia, Ali Al Nima, Oscar N.E. Kjell (2014). The affective profiles, psychological well-being, and harmony: Environmental mastery and self-acceptance predict the sense of a harmonious life. PeerJ, Volume 2, Article e259

Oscar N.E. Kjell, Sam Thompson (2013). Exploring the Impact of Positive and Negative Emotions on Cooperative Behaviour in a Prisoner’s Dilemma Game. PeerJ

Oscar N.E. Kjell, Ali A. Nima, Sverker Sikström, Trevor Archer, Danilo Garcia (2013). Iranian and Swedish adolescents: differences in personality traits and well-being. PeerJ, 1(e197)

Oscar N. E. Kjell (2011). Sustainable Well-Being: A Potential Synergy Between Sustainability and Well-Being Research. Review of General Psychology, 15(3), 255–266