Abnormal regional spontaneous brain activity in major depressive disorder with obesity comorbidity: A resting-state functional magnetic resonance imaging study

Table 1 The inclusion criteria and exclusion criteria of each group

Group	Inclusion criteria	Exclusion criteria
MDD-OB	(1) Outpatients meeting DSM-5 diagnostic criteria for MDD, with current MDE confirmed through the M.I.N.I 5.0 by trained psychiatrists; (2) HAMD-24 score ≥ 20; (3) First-episode, antidepressant-naive status at enrollment; and (4) BMI1 ≥ 28 kg/m2	(1) Presence of organic brain diseases; (2) Severe systemic diseases; (3) Intellectual disability (or: Mental retardation); (4) History of alcohol or substance abuse; (5) Visual or auditory impairments; (6) History of clinically diagnosed neurological disorders; and (7) Pregnant or lactating women
MDD	(1) Outpatients meeting DSM-5 diagnostic criteria for MDD, with current MDE confirmed through the M.I.N.I 5.0 by trained psychiatrists; (2) HAMD-24 score ≥ 20; (3) First-episode, antidepressant-naive status at enrollment; and (4) 18.5 ≤ BMI < 24 kg/m2
OB	(1) BMI ≥ 28 kg/m2; and (2) Exclusion of MDD and other conditions meeting exclusion criteria
HC	(1) 18.5 ≤ BMI < 24 kg/m2; and (2) Exclusion of MDD and other conditions meeting exclusion criteria
All participant groups	(1) Minimum education level: Completion of elementary school or higher; (2) Aged 18-60 years, irrespective of gender; and (3) Voluntary participation with written informed consent obtained after full explanation of study procedures

¹The body mass index classification in this article references[47].

MDD: Major depressive disorder; OB: Obesity; HC: Healthy control; DSM-5: The Diagnostic and Statistical Manual of Mental Disorders-5th version; MDE: Major depressive episode; M.I.N.I: Mini International Neuropsychiatric Interview; HAMD-24: Hamilton Depression Rating Scale-24; BMI: Body mass index.

Table 2 Demographic features of participants in the study, n (%)

Variables	HC (n = 37)	OB (n = 42)	MDD (n = 47)	MDD-OB (n = 23)	F/χ2	P value	Post-hoc analysis
Age	40.92 (8.61)	38.6 (9.21)	38.11 (12.99)	34 (11.02)	2.10	0.104
Sex (male/female)	14/23	23/19	23/24	7/16	5.02	0.171
BMI	23.24 (2.12)	30.96 (2.48)	22.36 (2.97)	33.14 (8.85)	61.01	< 0.001	OB > HC, MDD; MDD-OB > HC, OB, MDD-OB
HAMD-24	1.946 (2.95)	4.048 (6.77)	29.617 (11.33)	26.08 (14.101)	93.83	< 0.001	MDD > HC, OB; MDD-OB > HC, OB
Behavioral activation/inhibition
BASR	12.81 (1.74)	13.41 (1.68)	11.51 (2.59)	12.22 (1.91)	6.51	< 0.001	HC > MDD; OB > MDD, MDD-OB
BASD	11.39 (2.20)	17.41 (1.70)	15.51 (2.23)	15.87 (2.88)	49.52	< 0.001	OB > HC, MDD, MDD-OB; MDD > HC; MDD-OB > HC
BASF	14.28 (2.54)	20.03 (2.07)	18.33 (2.58)	19.35 (2.37)	40.32	< 0.001	OB > HC, MDD; MDD > HC; MDD-OB > HC
BIS	14.44 (2.01)	19.82 (2.42)	20.11 (3.39)	21.04 (2.23)	43.15	< 0.001	OB > HC; MDD > HC; MDD-OB > HC
Mean FD_Jenkinson1	0.8 (0.04)	0.11 (0.07)	0.09 (0.06)	0.11 (0.06)	2.10	0.102

¹Jenkinson mean framewise displacement.

HC: Healthy control; OB: Obesity; MDD: Major depressive disorder; BMI: Body mass index; HAMD-24: Hamilton Depression Rating Scale-24; BASR: Behavioral activation system-reward responsiveness; BASD: Behavioral activation system-drive; BASF: Behavioral activation system-fun seeking; BIS: Behavioral inhibition system.

Table 3 Brain areas with significantly different regional homogeneity values among healthy control, obesity, major depressive disorder, and comorbid major depressive disorder-obesity groups

Brain	Peak MNI Coordinates			F	Cluster size
	X	Y	Z
MTG.L	-57	-39	0	24.67	59
Cuneus.R	3	-84	36	28.39	36
Precuneus.L	-6	-78	45	29.6	50
Thalamus.L	-15	-27	0	25.05	26

MTG.L: Left middle temporal gyrus; Cuneus.R: Cuneus right; Precuneus.L: Precuneus left; Thalamus.L: Thalamus left.