{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,23]],"date-time":"2026-01-23T07:22:48Z","timestamp":1769152968014,"version":"3.49.0"},"reference-count":100,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2023,8,22]],"date-time":"2023-08-22T00:00:00Z","timestamp":1692662400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"University Hospital of the Friedrich-Alexander University","award":["01GL1745"],"award-info":[{"award-number":["01GL1745"]}]},{"name":"University Hospital of the Friedrich-Alexander University","award":["GRK2162\/270949263"],"award-info":[{"award-number":["GRK2162\/270949263"]}]},{"name":"Neurodevelopment and Vulnerability of the Central Nervous System","award":["01GL1745"],"award-info":[{"award-number":["01GL1745"]}]},{"name":"Neurodevelopment and Vulnerability of the Central Nervous System","award":["GRK2162\/270949263"],"award-info":[{"award-number":["GRK2162\/270949263"]}]},{"name":"Deutsche Forschungsgemeinschaft","award":["01GL1745"],"award-info":[{"award-number":["01GL1745"]}]},{"name":"Deutsche Forschungsgemeinschaft","award":["GRK2162\/270949263"],"award-info":[{"award-number":["GRK2162\/270949263"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Brain Sciences"],"abstract":"<jats:p>The development of Alzheimer\u2019s disease (AD) is influenced by sex hormones\u2014estrogens and androgens in particular. However, the impact of prenatal sex hormone exposure is less clear; very few investigations have examined the relationship between the second-to-fourth digit length ratio (2D:4D), a putative proxy for the ratio of prenatal estrogens to androgens, and AD, with inconsistent results among the few that have. Therefore, we aimed to investigate this relationship using methodologically robust metrics. In a 2 (sex) \u00d7 4 (group) MANOVA incorporating 108 participants (30 AD patients, 19 patients with tauopathy but no amyloidopathy, 31 clinical and 28 healthy age- and education-matched controls), the effects of sex and group on the dependent variables right and left 2D:4D were examined. We also explored the association between 2D:4D and the severity of AD symptoms assessed via neuropsychological examination. We did not find any significant differences in the right- and left-hand 2D:4D between patients with AD and the other groups; no significant associations between 2D:4D and neuropsychological task performances were found in the dementia groups. The 2D:4D of healthy women was significantly lower than that of depressed women without AD, i.e., clinical controls, but not significantly different from depressed female patients with AD. This investigation does not support the role of 2D:4D in the development or severity of AD in general, but suggests a potential role of 2D:4D for depression in women. Future studies are warranted to clarify whether 2D:4D can distinguish between early- and late-onset depression in women.<\/jats:p>","DOI":"10.3390\/brainsci13091229","type":"journal-article","created":{"date-parts":[[2023,8,22]],"date-time":"2023-08-22T08:58:54Z","timestamp":1692694734000},"page":"1229","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Digit Ratio (2D:4D) Is Not Associated with Alzheimer\u2019s Disease in the Elderly"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2482-5851","authenticated-orcid":false,"given":"Eva-Maria","family":"Siegmann","sequence":"first","affiliation":[{"name":"Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universit\u00e4t Erlangen-N\u00fcrnberg (FAU), Schwabachanlage 6, 91054 Erlangen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Pauline","family":"Olm","sequence":"additional","affiliation":[{"name":"Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universit\u00e4t Erlangen-N\u00fcrnberg (FAU), Schwabachanlage 6, 91054 Erlangen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6086-0924","authenticated-orcid":false,"given":"Bernd","family":"Lenz","sequence":"additional","affiliation":[{"name":"Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universit\u00e4t Erlangen-N\u00fcrnberg (FAU), Schwabachanlage 6, 91054 Erlangen, Germany"},{"name":"Department of Addictive Behavior and Addiction Medicine, Central Institute of Mental Health (CIMH), Medical Faculty Mannheim, Heidelberg University, 68159 Mannheim, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7517-9154","authenticated-orcid":false,"given":"Christiane","family":"M\u00fchle","sequence":"additional","affiliation":[{"name":"Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universit\u00e4t Erlangen-N\u00fcrnberg (FAU), Schwabachanlage 6, 91054 Erlangen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4369-6875","authenticated-orcid":false,"given":"Timo Jan","family":"Oberstein","sequence":"additional","affiliation":[{"name":"Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universit\u00e4t Erlangen-N\u00fcrnberg (FAU), Schwabachanlage 6, 91054 Erlangen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Juan Manuel","family":"Maler","sequence":"additional","affiliation":[{"name":"Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universit\u00e4t Erlangen-N\u00fcrnberg (FAU), Schwabachanlage 6, 91054 Erlangen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8096-3987","authenticated-orcid":false,"given":"Johannes","family":"Kornhuber","sequence":"additional","affiliation":[{"name":"Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universit\u00e4t Erlangen-N\u00fcrnberg (FAU), Schwabachanlage 6, 91054 Erlangen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,8,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1186\/s13195-019-0485-0","article-title":"Advantages and disadvantages of the use of the CSF Amyloid \u03b2 (A\u03b2) 42\/40 ratio in the diagnosis of Alzheimer\u2019s Disease","volume":"11","author":"Hansson","year":"2019","journal-title":"Alzheimers Res. 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