Transdiagnostic Considerations of Mental Health for the Post-COVID Era: Lessons from the First Surge of the Pandemic

The study addresses whether the mental health impact of the COVID-19 pandemic is best conceptualized as a transdiagnostic syndrome spanning DSM-5/ICD-11 categories rather than discrete disorders. Prolonged stress during the pandemic eroded coping capacity and produced a complex mix of symptoms across diagnostic boundaries. This raises concerns about multiple comorbid diagnoses complicating prevention and treatment. The authors hypothesize that a robust, non-random clustering of multiple symptoms exists and can be detected across different countries and methodologies.

The authors reviewed literature using Reference Citation Analysis, PubMed, and Google Scholar for the term "transdiagnostic" in the context of COVID-19 (2019–2022). They found widespread but often vague use of the term, frequently focusing on conventional comorbidity (e.g., depression and anxiety) and treatment applications rather than specifying empirically derived multi-symptom constellations that span diagnostic categories. Few studies examined three or more associated symptoms with sound methodology. The authors highlight the need for a precise, research-based transdiagnostic characterization of pandemic-related psychopathology, contrasting their approach with prior work that primarily informs treatment without a clearly defined, empirically supported diagnostic construct.

Two independent observational studies were analyzed. Study 1 (Israel): Three national surveys were conducted during the first surge of COVID-19 using probability-based representative sampling (details of timing not specified in the excerpt). Surveys assessed symptoms including depression, anxiety, loneliness (all three surveys), and phobia (surveys 2 and 3). Pearson correlations among symptoms were computed. Frequencies of individuals endorsing 0, 1, 2, 3, or 4 symptoms and the most common symptom combinations were tabulated, with temporal comparisons across surveys. Ethnic subgroup analyses compared Arab and Jewish respondents. Study 2 (Italy): A cross-sectional, anonymous, web-based survey of adults (≥18 years) was conducted March 25–April 7, 2020, approximately three weeks after the national lockdown and during the first contagion peak. Convenience sampling used sponsored Facebook advertisements (estimated ~100,000 link clicks; reach ~1,000,000). Participants provided online consent; the University of L'Aquila IRB approved procedures in accordance with the Declaration of Helsinki. Measures covered the prior two weeks: (1) GPS-PTSS (Global Psychotrauma Screen post-traumatic stress symptoms), clinical relevance defined as >3 of 5 PTSS items; (2) PHQ-9 for depression, severe symptoms cutoff ≥15; (3) GAD-7 for anxiety, severe symptoms cutoff ≥15; (4) GPS PTSD-NA cluster (11 items including disturbances in self-organization, anxiety, depression, self-harm, substance abuse, and other problems), reflecting complex PTSD-related negative affect; (5) Perceived Stress Scale (PSS), using the upper quartile to classify high perceived stress. Data analysis: For both datasets, Pearson correlations between symptom pairs were computed. Frequencies of all combinations of 3, 4, and 5 symptoms were analyzed to identify the most prevalent constellations. Proportion tests compared subgroups: in Italy, Italians vs foreigners and those with vs without prior psychiatric history (PH vs NoPH) for having 3, 4, or 5 symptoms. Bonferroni corrections addressed multiple comparisons. Temporal analyses (Israel) assessed progression in symptom complexity across surveys.

Israel: All pairwise symptom correlations were significant across the three surveys. Survey 1: 22.1% (95% CI: 19.7–24.5) reported all three symptoms (depression, loneliness, anxiety), significantly exceeding the most frequent 2-symptom pattern (depression and anxiety; 6.4%, 95% CI: 4.9–7.8; P < 0.001). Survey 2: 13.3% reported 3 symptoms and 20.1% reported all 4 symptoms; the 4-symptom combination prevalence (95% CI: 17.8–22.4) exceeded the most prevalent 3-symptom combination (phobia, anxiety, depression; 5.58%, 95% CI: 4.2–6.9; P < 0.001). Survey 3: 12.8% reported 3 symptoms and 24.3% reported all 4 symptoms; the 4-symptom combination prevalence (95% CI: 21.8–26.3) exceeded the most prevalent 3-symptom combination (phobia, anxiety, depression; 7.32%, 95% CI: 6.0–8.7; P < 0.001). Temporal progression: Survey 2 had significantly higher prevalence of 2- or 3-symptom combinations than Survey 1 (P < 0.0001 and P < 0.001, respectively); Survey 3 had higher prevalence of 4-symptom combinations than Survey 2 (P < 0.01), indicating increasing symptom complexity over time. No differences were found between Arab and Jewish subpopulations in the frequency of 3- and 4-symptom combinations. Italy: All pairwise correlations among anxiety, perceived stress, PTSS, depression, and PTSD-NA were significant (P < 0.001). The most frequent 3-symptom combination was PTSS, depression, and PTSD-NA (3.3%). The most frequent 4-symptom combination was anxiety, PTSS, depression, and PTSD-NA (3.2%). The most prevalent 5-symptom combination—anxiety, perceived stress, PTSS, depression, and PTSD-NA—was 9.0% (95% CI: 8.5–9.3), significantly higher than the most prevalent 3- and 4-symptom combinations (95% CIs: 3.0–3.5 and 2.9–3.4, respectively; P < 0.001). Italians vs foreigners: 3-symptom combinations were more frequent among foreigners (14.9%, 77/516) than Italians (11.3%, 2332/20701; P = 0.0119); no significant differences for 4 symptoms (9.3% vs 10.7%; P = 0.3173) or 5 symptoms (9.0% vs 8.9%; P = 1). Prior psychiatric history: Individuals with PH had higher rates of multiple symptoms than NoPH, with the same dominant combinations. Specifically: 3 symptoms—13.3% (805/6057) vs 10.6% (1604/15160), P < 0.0001; 4 symptoms—12.9% (782/6057) vs 7.9% (1191/15160), P < 0.0001; 5 symptoms—14.6% (885/6057) vs 6.7% (1021/15160), P < 0.0001.

Across two countries and different methodologies, complex constellations of co-occurring symptoms that cross DSM-5/ICD-11 diagnostic boundaries were common during the first pandemic surge and increased with time under prolonged stress. The strong intercorrelations and the predominance of multi-symptom profiles suggest a shared underlying process or overarching disorder, providing a more coherent characterization than assigning multiple comorbid diagnoses. The pattern generalized across ethnic subgroups and was more frequent in those with prior psychiatric history, indicating vulnerability effects. These findings support adopting a transdiagnostic framework—aligned with proposals such as the COVID Stress Syndrome—and complement calls for broader, empirically grounded diagnostic and organizational approaches (e.g., WPA guidelines). Transdiagnostic considerations may aid post-COVID planning where multiple stressors precipitate complex symptomatology.

Multiple co-occurring symptoms characterized the mental health response to the COVID-19 pandemic, frequently spanning DSM/ICD diagnostic categories. Symptom complexity was more common among individuals with prior psychiatric illness and increased with the pandemic’s duration. The results motivate consideration of a broader, empirically derived transdiagnostic category for pandemic-related psychopathology and potentially for post-COVID conditions driven by multiple stressors. Further international studies are warranted, including incorporation of neuropsychiatric effects, to refine diagnosis and optimize treatment and organizational planning.

The studies did not assess the full neuropsychiatric spectrum, including symptoms in individuals recovering from infection. The Israeli sample size was modest compared to the Italian sample, although nationally representative sampling was used. Despite data being from the first surge, similar results across two countries using different designs strengthen generalizability.