Table 1.

Demographic and Clinical Characteristics of the Study Sample:

Variable	MDD Higher-lethality Suicide Attempters (N= 11)		MDD Lower-lethality Suicide Attempters (N= 14)		MDD Suicide non-attempters (N= 66)		Analysis
*Demographic Characteristics*
	N	%	N	%	N%	%	χ²	p^a
Sex; Female	5	45	9	64.3	46	70	2.487	0.305
Race; White	5	45	7	50	44	67.7	13.499	0.118
Handedness; Right	7	63.6	10	71.4	52	78.8	2.692	0.315
	*Range*	*Mean (SD)*	*Range*	*Mean (SD)*	*Range*	*Mean (SD)*	F	p^b
Age (years)	18–56	33.4 (14.3)	19–60	35.9 (12.8)	18–64	34.5 (11)	0.151	0.860
Education (years)	11–18	14.3 (2.9)	11–22	15.7 (3.7)	11–22	16.1 (2.6)	1.630	0.202
*Clinical & Neuropsychological Measures*
Beck Depression Inventory	13–38	23.6 (10.0)	13–38	26.1 (9.1)	13–47	24.3 (9.0)	0.270	0.764
Hamilton Depression Rating Scale (17-item)	16–25	19.9 (3.7)	16–25	17.5 (4.7)	16–31	17.9 (5.0)	0.890	0.415
Barratt Impulsivity Scale	23–87	52.1 (19.6)	36–65	49.3 (10.1)	21–95	52.0 (14.9)	0.142	0.868
Brown Goodwin Aggression Scale	10–26	17.0 (5.5)	10–24	17.1 (4.1)	10–32	16.4 (3.7)	0.236	0.791
Stroop Interference^$	0.050–0.820	0.348 (0.267)	0.010–0.730	0.280 (0.190)	−0.0201.040	0.317 (0.221)	0.296	0.744
	N	%	N	%	N	%	χ²	p^c
Comorbid Anxiety Disorder	4	36.4	7	50.0	30	45.5	0.236	0.887
Past Substance Use Disorder	1	9.1	2	14.3	8	12.1	0.289	0.951
Borderline Personality Disorder	6	54.5	3	21.4	4	6.1	15.147	<0.001
*Suicide History*
Scale for Suicidal Ideation	0–33	16.7 (13.1)	0–24	6.3 (7.6)	0–21	3.9 (5.7)	15.137	<0.001
Number of actual suicide attempts	1–6	2.3 (1.7)	1–7	2.1 (1.7)			0.086	0.773
Suicide intent score of maximum-lethality attempt	6–25	16.2 (5.7)	11–24	16.7 (4.1)			0.067	0.798
Lethality score of maximum-	3–7	3.6	0–2	0.7			51.693	<0.001
lethality attempt		(1.2)		(0.8)
	N	%	N	%			χ²	p^a
Recency of last attempt; < 5 years	7	63.6	6	42.9			1.066	0.428

^a.

Chi-square analysis.

^b.

One-way ANOVA.

^c.

Fisher’s Exact test.

Score negatively scaled. Higher scores indicate poorer performance.

Abbreviations: MDD = major depressive disorder