Biological differences between melancholic and nonmelancholic depression subtyped by the CORE measure

Figures & data

Table 1 Sociodemographic and clinical variables for depressive and control groups

	Control (n=54)	CORE subtypes		P-value
		Nonmelancholic (n=20)	Melancholic (n=13)
Age (years)	47.4±9.97	48.4±7.7	52.8±10.7	0.20c
Female sex	74.1%	90.0%	76.9%	0.33a
HDRS	NA	21.8±2.9	22.6±2.9	0.81b
Lifetime tobacco use	NA	55%	53.8%	1.0a
BMI	NA	26.4±0.9	27.4±4.4	0.51b
Psychotic depression	–	10%	30.8%	0.18a
CORE (mean)	NA	3.4±2.5	13.1±5.0	<0.001d
Time current episode (average months)	–	20.0±18.1	29.0±36.3	0.65d
Episodes (n)	0	6.7±7.9	4.3±4.7	0.43d
Proportion on
Any AD	0	90%	84.6%	1.0a
TCA	0	50.0%	53.8%	1.0a
SSRIs	0	65.0%	53.8%	0.41a
Other AD	0	12.1%	0%	0.13a
Lithium	0	15.0%	23.1%	0.65a
Anticonvulsants	0	45.0%	46.2%	1.0a
Antipsychotics	0	25.0%	38.5%	0.46a

Notes: Analysis of age and sex comparing three groups, ie, control, nonmelancholic, and melancholic groups; all other variables were analyzed comparing two groups, nonmelancholic versus melancholic. Values displayed as the mean ± standard deviation or percentage

a chi-square, Fisher’s exact test

b Student’s t-test

c analysis of variance

d Mann–Whitney U-test.

Abbreviations: NA, not assessed; HDRS, Hamilton Depressive Rating Scale; BMI, body mass index; AD, antidepressant; TCA, tricyclic antidepressant; SSRIs, selective serotonin reuptake inhibitors.

Table 2 Serum biological data comparing depressive versus control groups

	Control (n=54)	Depressive (n=33)	P-value
BDNF	25.11±7.76	26.10±7.40	0.560
TBARS	10.26 (4.00)	10.26 (4.66)	0.871
PCC	0.03 (0.03)	0.69 (0.05)	<0.001**
IL-2	0.25 (0.08)	0.27 (0.11)	0.578
IL-4	0.64 (0.21)	0.75 (0.30)	0.026*
IL-6	0.88 (0.69)	1.28 (1.27)	0.004**
IL-10	0.37 (0.26)	0.32 (0.28)	0.564
TNF-α	0.98 (0.30)	0.99 (0.26)	0.997
IFN-γ	1.64 (0.34)	1.60 (0.29)	0.316
IL-17	12.84 (17.18)	7.87 (9.50)	0.089

Notes: BDNF is displayed as the mean ± standard deviation; other variables are displayed as the median and interquartile range. The statistical tests used were one-way analysis of variance test for BDNF and the Kruskal–Wallis test for other variables.

* P<0.05

** P<0.005.

Abbreviations: BDNF, brain-derived neurotrophic factor; TBARS, thiobarbituric acid reactive substances; PCC, protein carbonyl content; IL-2, interleukin-2; IL-4, interleukin-4; IL-6, interleukin-6; IL-10, interleukin-10; IL-17, interleukin-17; TNF-α, tumor necrosis factor-alpha; IFN-γ, interferon-gamma.

Table 3 Serum biological data returned by CORE-defined melancholic and nonmelancholic subsets and in comparison with control group

	Control (n=54)	Subtypes according to CORE model		P-value	Post hoc differences
		Nonmelancholic (n=20)	Melancholic (n=13)
BDNF	25.11±7.76	25.8±7.5	26.5±7.4	0.80	–
TBARS	10.26 (4.00)	10.93 (5.66)	8.93 (2.66)	0.03*	NM > M
PCC	0.03 (0.03)	0.06 (0.03)	0.06 (0.08)	<0.001*	C < (NM = M)
IL-2	0.25 (0.08)	0.27 (0.12)	0.24 (0.07)	0.65	–
IL-4	0.64 (0.21)	0.75 (0.20)	0.81 (0.37)	0.06	–
IL-6	0.88 (0.69)	1.28 (1.10)	1.45 (2.55)	0.01*	C < M
IL-10	0.37 (0.26)	0.28 (0.52)	0.34 (0.25)	0.84	–
TNF-α	0.98 (0.30)	0.97 (0.29)	1.02 (0.35)	0.69	–
IFN-γ	1.64 (0.34)	1.64 (0.72)	1.45 (0.39)	0.01*	(C = NM) > M
IL-17	12.84 (17.18)	7.51 (9.7)	7.99 (10.02)	0.22	–

Notes: All analysis comparing three groups: control, nonmelancholic, and melancholic groups according to the two models. BDNF is displayed as the mean ± standard deviation; other variables are displayed as the median and interquartile range. The last column shows a post hoc comparison between groups according to one-way analysis for BDNF or Kruskal–Wallis test for other variables.

* Indicates statistically significant P-values.

Abbreviations: BDNF, brain-derived neurotrophic factor; TBARS, thiobarbituric acid reactive substances; PCC, protein carbonyl content; IL-2, interleukin-2; IL-4, interleukin-4; IL-6, interleukin-6; IL-10, interleukin-10; IL-17, interleukin-17; TNF-α, tumor necrosis factor-alpha; IFN-γ, interferon-gamma; NM, nonmelancholic group; M, melancholic group; C, control group.