dr. J.T. Kraiss (Jannis)

Assistant Professor
BMS-HIB-PHT
Capitool 15 241
j.t.kraiss@utwente.nl
+31534897512
Business card

My research line

I am a researcher in the field of clinical psychology. A significant challenge in my field is accessibility of treatment and the fluctuating and heterogenous nature of mental disorders. My aim is to develop interventions that are accessible and provide dynamic and individualized mental health support. My work focuses on developing and evaluating just-in-time adaptive interventions (JITAIs). JITAIs are mobile (mHealth) interventions aimed at delivering in-situ support in critical moments via mobile devices, making treatment ubiquitous and responsive to individual needs.

In most of my work, I use the resaerch method of micro-randomized trials to study when and how JITAIs should be delivered. In a MRT, people are repeatedely randomized into either receiving an intervention option or not receiving it. This allows for causal inferences about the momentay effects of intervention options within JITAIs and their working mechanisms. I combine this method with ecological momentary assessment to understand in which moments in daily life JITAIs work, and how they work. I use this approach in various projects in different (sub)clincial populations to optimize and evaluate JITAIs, including people with bipolar disorder, depressive and anxiety disorders, and prolonged grief.

I am among the first researchers worldwide to lead a research line on mental health JITAIs. In total, I received > 1.25M (900k as main applicant) funding from various funding bodies, mainly on projects related to mental health JITAIs, micro-randomized, and ecological momentary asesmsent (see 'Projects'). In 2025, I received a VENI-grant for the development and evaluation of JITAIs for bipolar disorder. Currently, I am the daily supervisor of 5fte junior academic staff: 1 junior researcher (1fte) and 4 PhDs (4fte). Furthermore, I am involved in the supervsion of a postdoc-project on the evaluation of JITAIs for depression. I have (co)-authored 40+ papers in peer-reviwed academic journals.

Teaching & other activities

I gave lectures to 500+ psychology students on bipolar disorder, positive psychology, and ecological momentary assesmsent. I supervised  60+ bachelor and master theses (first supervisor), and coordinated several bachelor/master courses in the past. I am supervisor of two clinical psychologists in training.

Since 2025, I am vice-chair of the Examination Board Behavioural Sciences at the University of Twente. I have reviewed 40+ papers for journals such as NPJ Digital Medicine, Health Psychology Review, Nature Human Behavior, Behavior Research and Therapy, Behavior Research Methods, Journal of Affective Disorders. I gave 20+ presentations during (inter)national conferences or seminars for practitioners or patients.

Organisations

Publications

2026

Addressing mental health with daily-life ecological momentary interventions (ALERT) in people at increased risk for mental disorders: A micro-randomized trial (2026)Journal of Affective Disorders, 406. Article 121661 (E-pub ahead of print/First online). Fiß, F., Berndt, L., Anickova, S., Vaessen, T. & Kraiss, J.https://doi.org/10.1016/j.jad.2026.121661Identifying what works in mental health apps through meta-regression analyses of 169 trials (2026)npj Digital Medicine, 9. Article 336 (E-pub ahead of print/First online). Kraiss, J. T., Fiß, F., Chakhssi, F., Aktas, F. B., Koelen, J. A. & Piano Simões, J.https://doi.org/10.1038/s41746-026-02466-z

2025

An experience sampling study exploring associations between contextual factors and prolonged grief reactions in daily life (2025)Scientific reports, 15. Article 39410. Pociūnaitė-Ott, J., Kraiss, J., van Eersel, J. H. W., Franzen, M. & Lenferink, L. I. M.https://doi.org/10.1038/s41598-025-23122-8Nature-Based Contemplation for Spiritual Well-Being: A Pilot Study Exploring Acceptability and Potential Benefits (2025)Mindfulness, 16(11), 3212-3225. Ruan, X., Kraiss, J., Tönis, K. J. M., Cebolla, A., Lenferink, L. I. M., van Rompay, T. & Bohlmeijer, E.https://doi.org/10.1007/s12671-025-02686-6Can a positive psychology intervention cultivating self-compassion enhance mental health by fostering self-compassion and adaptive capacities? Results from a randomized controlled trial (2025)The Journal of positive psychology (E-pub ahead of print/First online). Wang, J., Tönis, K. J. M., Kraiss, J. T., Drossaert, C. H. C., Schroevers, M. J. & Bohlmeijer, E. T.https://doi.org/10.1080/17439760.2025.2568840Exploring Compassion-Based Positive Psychology for Cardiac Recovery: A Mixed Methods Case Study (2025)International Journal of Applied Positive Psychology, 10(3). Article 53. Tönis, K., Kraiss, J. T., Toivonen, H., Linssen, G. C. & Bohlmeijer, E. T.https://doi.org/10.1007/s41042-025-00247-9What Makes Mindfulness-Based Stress Reduction Programs Effective Among Dutch Elementary School Teachers? The Mediating Role of Mindfulness Skills, Self-Compassion, Emotion Regulation, and Teacher Self-Efficacy (2025)Mindfulness, 16(9), 2699-2711. Rombouts, M., Lensen, J. H., Kraiss, J. T., Duinhof, E. L., Monshouwer, K., Stoltz, S. E. M. J., Scholte, R. H. J., Speckens, A. E. M. & Kleinjan, M.https://doi.org/10.1007/s12671-025-02662-0Trial-based economic evaluation of a multicomponent positive psychology intervention for euthymic patients with bipolar disorder (2025)Journal of Affective Disorders, 379, 576-585. Kleijburg, A., Klein, F., Wijnen, B., Lokkerbol, J., ten Klooster, P. M., Bohlmeijer, E. T. & Kraiss, J. T.https://doi.org/10.1016/j.jad.2025.02.112Psychometric evaluation of a brief self-report measure and of EMA items assessing the suicide crisis syndrome: Insights on reliability, validity and temporal variability (2025)Psychiatry research, 348. Article 116504. Spangenberg, L., Kraiss, J., Friedrich, M., Forkmann, T., Böhler, L., Strauss, M., Stengler, K., Serebriakova, J., Eimen, J., Teismann, T., Melzer, L. & Glaesmer, H.https://doi.org/10.1016/j.psychres.2025.116504A school-based program to prevent depressive symptoms and strengthen well-being among pre-vocational students (Happy Lessons): Results of a randomized controlled trial (2025)Mental Health & Prevention, 37. Article 200398. Rombouts, M., Monshouwer, K., Duinhof, E. L., Kraiss, J. T., Shields-Zeeman, L. & Kleinjan, M.https://doi.org/10.1016/j.mhp.2025.200398

Research profiles

VENI-grant: just-in-time adaptive interventions for bipolar disorder
Funded by the Dutch Research Council (NWO)

Toward recovery-oriented case formulations as the foundation for evidence-based personalized care in mental health services
PhD project of Emma Smeenge (external)

Broad and sustainable implementation of ‘Living well with bipolar disorder’
Funded by the Netherlands Organisation for Health Research and Development (ZonMw)

Towards evidence-based just-in-time adaptive interventions for depression and anxiety
PhD project of Felix Fiß
Funded by the University of Twente, Faculty of Behavioural, Management and Social Sciences

The right help at the right time for persistent grief disorder: Co-creation and innovative evaluation of the Grief HelpApp
PhD project of Veerle van Garling
Funded by Fonds Slachtofferhulp and Erasmus University Rotterdam

Behavioral activation just-in-time adaptive interventions for depression
Funded by the Netherlands Organisation for Health Research and Development (ZonMw)

Addressing mental health with daily-life ecological momentary interventions (ALERT) in people at increased risk for mental disorders
Funded by the University of Twente, Faculty of Behavioural, Management and Social Sciences

The cognitive stress response in daily life
PhD project of Xiaochang Zhao
Funded through the Gravitation Grant of the Dutch Research Council (NWO) and the Dutch Ministry of Education, Culture and Science

Development of nature-based interventions for spiritual well-being
PhD project of Xingjian Ruan
Funded by the Chinese Scholarship Council

Address

University of Twente

Capitool 15 (building no. 78), room 241
Capitool 15
7521 PL Enschede
Netherlands

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University of Twente

Cubicus (building no. 41)
De Zul 10
7522 NJ Enschede
Netherlands

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University of Twente

Cubicus (building no. 41), room B127A
De Zul 10
7522 NJ Enschede
Netherlands

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