Potential Biomarkers for Diagnosing Major Depressive Disorder Patients with Suicidal Ideation

Figures & data

Table 1 Baseline Data of MDD Patients and Healthy Controls

Variables	HCs	MDD Patients with SI	MDD Patients without SI	P-value
Number	86	53	20	–
Age	37.35(13.94)	32.34(14.43)	37.34(13.18)	0.11^a
Sex (F/M)	52/34	33/20	12/8	0.97^b
BMI (kg/m^2)	23.09(2.14)	23.41(2.37)	24.61(1.81)	0.21^a
Education (years)	11.71(4.10)	11.91(3.45)	12.15(3.69)	0.90^a
Smoke (Y/N)	26/60	16/37	4/16	0.68^b
FHMI (Y/N)	5/81	3/50	1/19	0.56^b
Marital status (Y/N)	51/35	32/21	10/10	0.71^b
HDRS scores	1.35(1.48)	32.34(8.50)*	26.80(7.11) ^#	<0.00001^a
BSI-CV scores	0.47(0.88)	12.64(2.65) *	7.55(1.43) ^#	<0.00001^a

Notes: ^aP-value was obtained from one-way analysis of variance; p-value>0.05 indicated that there was no significant difference in any group comparison, and p<0.05 indicated that there was significant difference in, at least, one group comparison. ^bP-value was obtained from chi-square test; p-value>0.05 indicated that there was no significant difference in any group comparison, and p<0.05 indicated that there was significant difference in, at least, one group comparison. *HDRS scores and BSI-CV scores were significantly higher in MDD with SI than in HCs or MDD without SI. ^#HDRS scores and BSI-CV scores were significantly higher in MDD without SI than in HCs.

Abbreviations: HCs, healthy controls; F, female; M, male; Y, yes; N, no; HDRS, Hamilton Depression Rating Scale; BMI, body mass index; MDD, major depressive disorder; BSI-CV, Beck Scale for Suicide Ideation-Chinese Version; SI, suicidal ideation; FHMI, family history of mental illness.

Figure 1 Discrimination model built using MDD patients with SI and HCs in training set: (A) The built OPLS-DA model showing an obvious separation between MDD patients with SI (red dot) and HCs (green dot); (B) 399-iteration permutation test showed that the model was valid, as the Q2 and R2 values yielded by the permutation test (bottom left) were significantly lower than their original values (top right).

Figure 2 T-predicted scatter plot from the OPLS-DA model: (A) both MDD patients with SI (lemon dot) and HCs (purple dot) from testing set could be correctly predicted; (B) the model was effective in distinguishing MDD patients with SI (red dot) from MDD patients without SI (blue dot).

Figure 3 Potential biomarkers for diagnosing MDD patients with SI: (A) the differences of these four potential biomarkers among the three groups; (B) the levels of potential biomarkers in the 20 MDD patients with SI were increased after one-month treatment, and both HDRS score and BSI-CV score were also significantly improved.

Figure 4 Diagnostic performances of these potential biomarkers. The panel consisting of these potential biomarkers yielded the excellent diagnostic performances with AUC>9.0 in training set, testing set and blind set.