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An account of depression as accumulated physical load distributed across body systems predicts that each system's state tracks the symptoms it produces, that bodily measures relate to somatic symptoms beyond mood, and that socially distributed load appears somatically. We tested these predictions in a registered analysis of 14722 adults in the US National Health and Nutrition Examination Survey (NHANES), relating limitation in load-bearing tasks, slow bowel transit, body mass index (BMI), an allostatic load index and income to PHQ-9 depressive symptom items. Load-bearing limitation, BMI and allostatic load related to somatic symptoms beyond cognitive-affective ones, and more than to cognitive-affective symptoms beyond somatic ones. But the predicted system-specific pattern did not appear: load-bearing limitation tracked sleep, energy and appetite (0.2946) far more than slow transit did (0.0404). Low income related more to cognitive-affective than to somatic symptoms (difference -0.0996). Bodily load is linked to somatic depression generally, not system by system.

• Published, Reproduced, Reviewed.Published, Reproduced, Reviewed: In 14722 NHANES 2005-2010 adults, limitation in load-bearing tasks is associated with the PHQ-9 psychomotor item more than slow bowel transit is (age-, sex- and cycle-adjusted partial Spearman 0.2038 vs 0.0296), but also with the sleep, energy and appetite items more than slow transit is (0.2946 vs 0.0404; difference -0.2542, 95% CI -0.2762 to -0.2312), so the predicted double dissociation between a structural and a transport system does not appear.
• Published, Reproduced, Reviewed.Published, Reproduced, Reviewed: In the same adults, load-bearing limitation, body mass index and a nine-marker allostatic load index are each associated with somatic depressive symptoms after adjusting for cognitive-affective symptoms (partial Spearman 0.1916, 0.0558, 0.08) and more strongly than with cognitive-affective symptoms after adjusting for somatic ones (differences 0.0711, 0.0399, 0.0646; Holm-adjusted p 0.002, 0.016, 0.002), whereas slow bowel transit shows no such specificity (difference 0.0074, 95% CI -0.0209 to 0.0347).
• Published, Reproduced, Reviewed.Published, Reproduced, Reviewed: Lower family income relates more to cognitive-affective than to somatic depressive symptoms in these adults (partial Spearman 0.1275 vs 0.0279; difference -0.0996, 95% CI -0.1299 to -0.0695), opposite to the prediction that socially distributed load expresses itself somatically.

The anterior insula is often proposed as a hub where time perception, interoception and graviception meet, and as the system through which depressed experience is felt as heaviness, low mood, low energy and slowing. Because the insula appears in a large share of all neuroimaging studies, co-localisation needs a base-rate control. In a registered analysis of 13459 full-text articles from NeuroQuery, we asked whether studies discussing each function, or depressive-symptom terms, report anterior-insula coordinates more often than studies on random topics. Interoception studies did (association z 10.259), but equally in the posterior insula; time perception (z {{R1.terms.time perception.anterior_insula.z}}) and vestibular studies (z -0.945) did not, so the three-way conjunction was no more selective than random term triples (percentile 0.5456). Symptom terms were not selective either (percentile 0.7064). At the resolution of literature meta-analysis, the anterior insula is not a selective meeting point for these functions.

• Published, Reproduced, Reviewed.Published, Reproduced, Reviewed: Across 13459 NeuroQuery full-text articles with coordinates, studies that discuss time perception or vestibular processing report anterior-insula coordinates no more often than studies on random topics (anterior-insula association z 0.424 and -0.945; percentiles 0.4959 and 0.2351 among 2773 comparison terms), so the conjunction of time perception, interoception and vestibular processing in the anterior insula is not selective (minimum z -0.945, percentile 0.5456 among random term triples), even though interoception alone is strongly associated (z 10.259).