Improving detection and treatment of health anxiety : diagnostic tools, digital interventions, and substance-related risks

Background: Severe health anxiety is a disabling condition characterized by excessive fear of illness, leading to distress, functional impairment, and reduced quality of life. Despite available evidence-based treatments, many affected individuals remain undiagnosed and untreated. This thesis aimed to improve the identification, treatment, and understanding of severe health anxiety by examining diagnostic tools, treatment effectiveness, and potential negative consequences.

Study 1: The first study evaluated the Swedish version of the Short Health Anxiety Inventory (SHAI-14), when used as a screening tool for severe health anxiety. Using data from 1,729 psychiatric patients and 85 healthy controls, the study established optimal cut-off scores for different clinical settings and explored severity classifications. Results confirmed SHAI-14's diagnostic accuracy and its potential use in routine screening and treatment outcome monitoring.

Study 2: The second study assessed the effectiveness of guided internet-based cognitive behavioural therapy (ICBT) for severe health anxiety in routine psychiatric care. A total of 447 patients completed a 12-week ICBT program, and the primary outcome was the 14-item Short Health Anxiety Inventory (SHAI-14). A within-group design with repeated measures was utilized for the primary analysis. The treatment was associated with significant symptom reductions and high patient satisfaction. Participants who completed more treatment modules experienced greater reductions in SHAI-14 scores, emphasizing the importance of patient engagement in digital interventions.

Study 3: The third study explored the feasibility of a brief, unguided digital self- care intervention for severe health anxiety. Adapted from the ICBT program in Study 2, this intervention aimed to improve accessibility by reducing treatment length and complexity. In this uncontrolled study, 25 participants completed the intervention, with the SHAI-14 as the primary outcome measure. Despite the lack of therapist support, participants reported significant symptom improvement at post-treatment, suggesting that brief self-guided interventions may serve as a viable option for individuals preferring unguided treatment. Future studies should evaluate its efficacy in controlled trials.

Study 4: The fourth study investigated the association between severe health anxiety and substance-related problems using Swedish register data. A cohort of 4,129 individuals diagnosed with ICD-10 hypochondriasis was compared with 41,290 matched controls from the general population. The results revealed a 2.55-fold increased risk of substance-related problems, after controlling for sociodemographic factors and family history of substance-related problems. Although psychiatric comorbidities attenuated the association, the risk remained significant. The results highlight the need for routine substance use screening in individuals with severe health anxiety.

Conclusions: This thesis advances the understanding of severe health anxiety by validating a practical screening tool, demonstrating the effectiveness of ICBT in routine psychiatric care, assessing the feasibility of a self-guided digital intervention, and identifying an elevated risk of substance-related problems in affected individuals. These findings highlight the importance of improved screening strategies, expanded access to evidence-based treatments, and the development of preventive measures to address long-term risks.

List of scientific papers

The following manuscripts and publications were included in the thesis:

I. Österman, S., Axelsson, E., Lindefors, N., Hedman-Lagerlöf, E., Hedman-Lagerlöf, M., Kern, D., Svanborg, C., & Ivanov, VZ. (2022). The 14-item short health anxiety inventory (SHAI-14) used as a screening tool: appropriate interpretation and diagnostic accuracy of the Swedish version. BMC Psychiatry, 22 (701).
https://doi.org/10.1186/s12888-022-04367-3

II. Österman, S., Axelsson, E., Forsell, E., Svanborg, C., Lindefors, N., Hedman-Lagerlöf, E., & Ivanov, VZ. (2024). Effectiveness and prediction of treatment adherence to guided internet-based cognitive behavioral therapy for health anxiety: A cohort study in routine psychiatric care. Internet Interventions, 38, Article 100780.
https://doi.org/10.1016/j.invent.2024.100780

III. Österman, S., Hentati, A., Forsell, E., Axelsson, E., Hedman-Lagerlöf, E., Lindefors, N., Ivanov, VZ., & Kraepelien, M. (2023). A Brief Digital Self-Care Intervention for Health Anxiety in a Swedish Medical University Clinic: A Prospective Single-Group Feasibility Study. BMJ Open, 13(12), Article e077376.
https://doi.org/10.1136/bmjopen-2023-077376

IV. Isomura, K *. , Österman, S *. , Hedman-Lagerlöf, E., Kuja-Halkola, R., Brikell, I., Chang, Z., D'Onofrio, B., Larsson, H., Lichtenstein, P., Mataix- Cols, D., Fernández de la Cruz, L., Ivanov, VZ., & Sidorchuk, A. Risk of substance-related problems in hypochondriasis. [Manuscript]

* Shared first authorship