Table 1.

Studies included in the analysis of gender identity

Study: First author’s surname (if one or more than two authors)	Year	Sample	Mean age	Technique
Berglund	2008	12 MtF–12 MC–12 FC	32–26–33	PET
Burke	2014	17 FtM–19 MtF–19 FC–20 MC	9.6–10.4–9.7–9.5	fMRI
Burke	2016	21 FtM–21 FC–20 MC	16.1–16.3–15.9	fMRI
Clemens	2017	15 MtF–21 MC–20 FC	35.5–32.32–32.5	rs-fMRI
Feusner	2017	27 FtM–27 FC–27 MC	24.2–32.1–31	rs-fMRI
Gizewski	2009	12 MtF–12 MC–12 FC	36–29–29	fMRI
Hahn	2015	23 FtM–21 MtF–25 FC–25 MC	26.9–30.9–25.3–25.6	MRI
Hoekzema	2015	54 FtM–37 MtF–52 FC–44 MC	16.92–16.05–16.29–16.42	MRI
Junger	2014	16 MtF–21 MC–20 FC	36.38–32.35–33.16	fMRI
Kranz	2014a	14 MtF–13 MC–9 FC	31.4–29.8–29	PET
Kranz	2014b	23 FtM–21 MtF–23 FC–22 MC	25.91–30.86–25.96–25.45	MRI
Kranz	2015	14 FtM–19 MtF–11 FC–24 MC	28.21–31.79–30.43–34.14	PET
Kranz	2018	25 FtM–12 FC–13 MC	27.24–24.42–28.77	MRI
Ku	2013	12 FtM–11 MtF–12 FC–11 MC	All Trans 25.4–All Cis 24.4	rs-fMRI
Lin	2014	12 FtM–11 MtF–12 FC–11 MC	All Trans 25.4–All Cis 24.4	rs-fMRI
Luders	2009	24 MtF–30 MC–30 FC	46.73–46.57–46.77	MRI
Manzouri	2017	28 FtM–34 FC–34 MC	23.5–27.6–28.8	MRI and rs-fMRI
Nawata	2010	11 FtM–9 FC	23.4–23.6	SPECT
Nota	2017	13 FtM–18 MtF–18 FC–21 MC	9.7–10.5–9.6–9.4	rs-fMRI
Pol	2006	6 FtM–8 MtF–6 FC–9 MC	28–25–23–25	MRI
Rametti	2011a	18 FtM–19 FC–24 MC	28.24–31.22–33	MRI
Rametti	2011b	18 MtF–19 MC–19 FC	24.74–31.94–33	MRI
Santarnecchi	2012	1 FtM–25 FC–25 MC	22–21–21	rs-fMRI
Savic and Arver	2011	24 MtF–24 MC–24 FC	32–33–35	MRI
Schöning	2010	11 MtF–11 MC	37.55–33.09	fMRI
Simon	2013	7 FtM–10 MtF–7 FC–11 MC	24.8–28.5–23.9–27.1	MRI
Soleman	2013	11 FtM–6 MtF–26 FC–24 MC	14.64–14.25–14.44–14.68	fMRI
Spies	2016	33 FtM–24 MtF–44 FC–33 MC	26.79–30.25–26.16–27.48	rs-fMRI
Yokota	2005	28 FtM–22 MtF–211 FC–211 MC	Not reported	MRI
Zubiaurre-Elorza	2013	24 FtM–18 MtF–23 FC–29 MC	26.21–25.5–31.09–29.28	MRI

FtM, female-to male; MtF, male-to-female; FC, female control; MC, male control