. Author manuscript; available in PMC: 2021 Dec 13.

Published in final edited form as: J Affect Disord. 2021 Aug 29;295:513–521. doi: 10.1016/j.jad.2021.08.061

Table 4.

Cerebrovascular Responses to Hypercapnia in the MCA and ICA.

Variable	baseline	P_ETCO₂ =3 mmHg	P_ETCO₂ =6 mmHg	P_ETCO₂ =9 mmHg	group p-value (η_p²)	hypercapnia p-value (η_p²)	interaction p-value (η_p²)
MCAv (cm•sec⁻¹)
HA	71.7 ± 16.0	75.7 ± 18.6	89.0 ± 19.5^*	101.7 ± 17.9^*	0.86(0.001)	<0.01(0.87)	0.19(0.05)
MDD	74.8 ± 15.7	76.2 ± 16.5	91.8 ± 18.9^*	99.7 ± 19.5^*	0.86(0.001)	<0.01(0.87)	0.19(0.05)
CVCi (cm•sec⁻¹•mmHg⁻¹)
HA	0.82 ± 0.2	0.89 ± 0.2	1.00 ± 0.2^*	1.14 ± 0.2^*	0.86(0.001)	<0.01(0.85)	0.09(0.07)
MDD	0.86 ± 0.2	0.88 ± 0.2	1.04 ± 0.2^*	1.12 ± 0.2^*	0.86(0.001)	<0.01(0.85)	0.09(0.07)
ICA D (mm)
HA	4.8 ± 0.7	4.8 ± 0.8	4.8 ± 0.8	4.8 ± 0.8	0.52(0.02)	0.16(0.07)	0.42(0.04)
MDD	5.0 ± 0.8	5.0 ± 0.6	4.9 ± 0.7	5.1 ± 0.7	0.52(0.02)	0.16(0.07)	0.42(0.04)
${\dot{Q}}_{I C A}$ (ml•min⁻¹)
HA	444 ± 173	414 ± 210	490 ± 256	614 ± 257^*	0.85(0.001)	<0.01(0.68)	0.46(0.04)
MDD	422 ± 116	411 ± 138	500 ± 161^*	576 ± 162^*	0.85(0.001)	<0.01(0.68)	0.46(0.04)
CVC (ml•min⁻¹•mmHg⁻¹)
HA	5.10 ± 2.0	4.89 ± 2.4	5.57 ± 3.0	6.94 ± 3.2^*	0.80(0.02)	<0.01(0.62)	0.44(0.04)
MDD	4.85 ± 1.3	4.75 ± 1.6	5.66 ± 1.8^*	6.41 ± 1.6^*	0.80(0.02)	<0.01(0.62)	0.44(0.04)

MCA, middle cerebral artery; ICA, internal carotid artery; MCAv, MCA mean velocity; CVCi, cerebrovascular conductance index; ICA D, ICA diameter; ${\dot{Q}}_{ICA}$ : ICA blood flow; CVC, cerebrovascular conductance; HA, healthy non-depressed adults; MDD, major depressive disorder; P_ETCO₂, end-tidal carbon dioxide. Values are mean ± SD; effect sizes are reported as partial eta squared (η_p²).

p<0.05 vs. baseline.