All study patients, hospitalized after SA (n=56) were divided into the following two groups: suicide attempters with a history of at least one suicide attempt (first SA group, n=29 ), and suicide attempters who reported more than one suicide attempt during the lifetime (SA>1 group, n=27). As reported in Table 1, the groups did not differ significantly in age, gender, psychiatric diagnoses or method of suicide attempt, but they did vary in terms of marital status, with a greater proportion of single participants in the first SA group.
Table 1 Demographic characteristics of all study subjects.
|
HC (n=54)
|
All patients after SA (n=56)
|
pa
|
First SA group
(n=29)
|
SA>1 group
(n=27)
|
F/p c2
|
Age mean (SD), years range
|
41.0 (16.3) 18-77
|
40.8 (16.8) 18-74
|
0.955
|
41.1 (18.1)
|
40.6 (15.6)
|
0.993a
|
Gender,
M/F, n (%)
|
19/35 (35.2/64.8)
|
22/34
(39.3/60.7)
|
0.656
|
14/15
48.3/51.7
|
8/19
29.6/70.4
|
0.320a
|
Residential area, rural/urban, n (%)
|
|
11/45 (19.6/80.4)
|
|
3/26
10.3/89.7
|
8/19
29.6/70.4
|
0.070
|
Marital status, married/single, n (%)
|
|
27/29
(48.2/51.8)
|
|
10/19
34.5/65.5
|
17/10
63/37
|
0.033
|
Psychiatric diagnosis,
MDD/ otherb, n (%)
|
|
21/35 (37.5/62.5)
|
|
10/19
34.5/65.5
|
11/16
40.7/59.3
|
0.418
|
Age at first SA, years
|
|
38.2 (17.2)
|
|
41.1 (18.1)
|
35.1 (15.9)
|
0.201
|
History of SA,
First time/repeated, n (%)
|
|
29/27
(51.8/48.2)
|
|
–
|
–
|
|
Method of SA, drugs/physical, n (%)
|
|
31/25 (55.4/44.6)
|
|
16/13
55.2/44.8
|
15/12
55.6/44.4
|
0.595
|
Alcohol intoxication during SA,
Yes/no, n (%)
|
|
22/34
(39.3/60.7)
|
|
12/17
41.4/58.6
|
10/17
37/63
|
0.477
|
HC, Healthy controls; SA, Suicide attempt; SD, Standard deviation; M, Male; F, Female; MDD, major depressive disorder;
pa value between three groups: HC, first SA, SA>1.
bother diagnoses include: anxiety disorder, personality disorder, adjustment disorder.
The volumetric analysis of all brain structures was done. Overall, significant differences between all SA patients and healthy controls groups were found in frontal and TC thickness and in volume of the left and right parts of hippocampus. Decreased cortical thicknesses were observed in both hemispheres. Analysis of other brain regions did not reveal significant results.
The analysis of frontal cortex thickness is shown in Table 2. The comparison between the patients after first SA and HC revealed the significant lower cortical thickness of the superior frontal (p=0.041) and rostral middle frontal (p=0.016) areas of the left hemisphere and superior frontal area (p=0.021) of the right hemisphere, with relative 3.5, 3.58 and 4.19 % difference of mean cortical thickness in these cortex areas, respectively. Moreover, the comparison between the SA>1 group and controls revealed the significant lower frontal cortical thickness in ten areas of the left hemisphere and seven areas of the right hemisphere, with relatively higher difference (4.02 to 8.33 %) of the mean cortical thickness between these two groups. Differences in four of frontal cortex regions were highly significant (p<0.0001) in patients with SA>1 as compared with the control group.
Table 2 The significant differences in means of frontal cortex thickness between the patients after first suicide attempt, repeated suicide attempts and study controls (HC, first SA and SA>1).
Hemisphere
|
Frontal cortex part
|
Mean cortical thickness (95% CI) in mm
|
ANCOVA age adjusted
|
|
|
HC (n=54)
|
First SA (n=29)
|
Post-hoc
|
% diff.
|
SA>1 (n=27)
|
Post-hoc
|
% diff.
|
|
|
|
|
1
|
2
|
1 vs. 2
|
1-2
|
3
|
1 vs 3
|
1-3
|
F2.106
|
p
|
Left
|
Lateral orbitofrontal
|
2.79 (2.75-2.83)
|
2.72 (2.66-2.77)
|
0.140
|
2.50
|
2.66 (2.60-2.72)
|
0.002
|
4.65
|
6.71
|
0.002
|
|
Medial orbitofrontal
|
2.55 (2.50-2.58)
|
2.54 (2.49-2.60)
|
1.000
|
0.39
|
2.42 (2.36-2.48)
|
0.003
|
5.09
|
6.74
|
0.002
|
|
Pars opercularis
|
2.66 (2.61-2.72)
|
2.58 (2.51-2.65)
|
0.149
|
3.00
|
2.48 (2.41-2.55)
|
<0.001
|
6.77
|
11.29
|
<0.001
|
|
Pars orbitalis
|
2.88 (2.82-2.94)
|
2.78 (2.70-2.86)
|
0.142
|
3.47
|
2.69 (2.61-2.77)
|
0.001
|
6.59
|
7.32
|
0.001
|
|
Pars triangularis
|
2.56 (2.51-2.61)
|
2.49 (2.43-2.56)
|
0.329
|
2.73
|
2.41 (2.34-2.48)
|
0.002
|
5.85
|
6.40
|
0.002
|
|
Precentral
|
2.52 (2.46-2.56)
|
2.42 (2.35-2.48)
|
0.093
|
3.96
|
2.31 (2.24-2.38)
|
<0.001
|
8.33
|
10.34
|
<0.001
|
|
Rostral middle frontal
|
2.51 (2.47-2.54)
|
2.42 (2.37-2.47)
|
0.016
|
3.58
|
2.37 (2.32-2.42)
|
<0.001
|
5.58
|
11.48
|
<0.001
|
|
Superior frontal
|
2.85 (2.81-2.90)
|
2.75 (2.68-2.81)
|
0.041
|
3.50
|
2.66 (2.59-2.73)
|
<0.001
|
6.67
|
11.11
|
<0.001
|
|
Frontal pole
|
2.84 (2.76-2.91)
|
2.76 (2.65-2.87)
|
0.765
|
2.81
|
2.66 (2.55-2.77)
|
0.032
|
6.33
|
3.43
|
0.036
|
|
Caudal middle frontal
|
2.64 (2.59-2.69)
|
2.54 (2.48-2.61)
|
0.058
|
3.78
|
2.50 (2.43-2.69)
|
0.002
|
5.3
|
6.78
|
0.002
|
Right
|
Lateral orbitofrontal
|
2.73 (2.68-2.77)
|
2.69 (2.63-2.75)
|
0.944
|
1.46
|
2.62 (2.56-2.68)
|
0.013
|
4.02
|
4.28
|
0.016
|
|
Pars opercularis
|
2.63 (2.57-2.68)
|
2.57 (2.49-2.65)
|
0.824
|
2.28
|
2.48 (2.40-2.56)
|
0.011
|
5.70
|
4.39
|
0.015
|
|
Pars orbitalis
|
2.86 (2.79-2.91)
|
2.81 (2.72-2.89)
|
1.000
|
1.74
|
2.71 (2.62-2.80)
|
0.026
|
5.24
|
3.58
|
0.031
|
|
Pars triangularis
|
2.55 (2.49-2.60)
|
2.51 (2.44-2.58)
|
1.000
|
1.56
|
2.42 (2.35-2.49)
|
0.016
|
5.09
|
4.07
|
0.020
|
|
Precentral
|
2.46 (2.41-2.51)
|
2.39 (2.32-2.46)
|
0.290
|
2.84
|
2.31 (2.24-2.38)
|
0.002
|
6.09
|
6.42
|
0.002
|
|
Rostral middle frontal
|
2.46 (2.41-2.50)
|
2.42 (2.36-2.49)
|
1.000
|
1.62
|
2.35 (2.92-2.42)
|
0.040
|
4.47
|
3.19
|
0.045
|
|
Superior Frontal
|
2.86 (2.81-2.91)
|
2.74 (2.68-2.81)
|
0.021
|
4.19
|
2.68 (2.62-2.75)
|
<0.001
|
6.29
|
9.58
|
<0.001
|
|
Caudal middle frontal
|
2.59 (2.54-2.64)
|
2.51 (2.44-2.58)
|
0.267
|
3.08
|
2.48 (2.40-2.55)
|
0.054
|
4.24
|
3,33
|
0.039
|
HC, healthy controls; SA, Suicide attempt.
F, p-values are based on the pairwise comparisons among the means (three groups: HC, first SA, SA>1).
% diff - relative difference describes the difference of the mean cortical thickness between two groups: HC and patients after SA.
Significant p-values (p<0.05) are indicated in bold.
Table 3 presented the comparison of thickness of temporal and frontal cortex among study groups. Patients after first SA, in comparison to HC, had significantly lower cortical thickness of the inferior (p=0.002), middle (p=0.013) and superior (p=0.006) temporal areas of the left hemisphere, with relative 4.09, 4.02 and 4.49 % difference of mean cortical thickness in these cortex areas, respectively. In patients with SA>1, in comparison to controls, the significant lower TC thickness was observed in the six areas of both hemispheres, with a difference (3.90 to 6.04 %) of the mean cortical thickness between these two groups. Differences in the inferior and middle temporal areas of the left hemisphere were observed as highly significant (p<0.001).
Table 3 The significant differences in means of temporal cortex thickness between the patients after first suicide attempt, repeated suicide attempts and study controls (HC, first SA and SA>1)
Hemisphere
|
Temporal cortex part
|
Mean cortical thickness (95% CI) in mm
|
ANCOVA age adjusted,
|
|
|
HC (n=54)
|
First SA (n=29)
|
Post-hoc
|
% diff.
|
SA> (n=27)
|
Post-hoc
|
% diff.
|
|
|
|
|
1
|
2
|
1 vs. 2
|
1-2
|
3
|
1 vs 3
|
1-3
|
F2.106
|
p
|
Left
|
Fusiform
|
2.78 (2.73-2.83)
|
2.73 (2.66-2.80)
|
0.573
|
1.79
|
2.67 (2.60-2.74)
|
0.031
|
3.90
|
3.53
|
0.033
|
|
Inferior temporal
|
2.93 (2.89-2.98)
|
2.81 (2.75-2.87)
|
0.002
|
4.09
|
2.78 (2.72-2.83)
|
<0.001
|
5.01
|
11.55
|
<0.001
|
|
Middle temporal
|
2.98 (2.93-3.03)
|
2.86 (2.80-2.93)
|
0.013
|
4.02
|
2.80 (2.73-2.86)
|
<0.001
|
6.04
|
11.29
|
<0.001
|
|
Superior temporal
|
2.89 (2.84-2.93)
|
2.76 (2.70-2.83)
|
0.006
|
4.49
|
2.76 (2.69-2.82)
|
0.005
|
4.49
|
7.61
|
0.001
|
|
Temporal pole
|
3.76 (3.67-3.85)
|
3.59 (3.47-3.72)
|
0.100
|
4.52
|
3.54 (3.41-3.66)
|
0.015
|
5.85
|
4.88
|
0.009
|
Right
|
Superior temporal
|
2.89 (2.84-2.95)
|
2.85 (2.77-2.92)
|
0.995
|
1.38
|
2.77 (2.69-2.85)
|
0.036
|
4.15
|
3.27
|
0.042
|
HC, healthy controls; SA, Suicide attempt.
F, p-values are based on the pairwise comparisons among the means (three groups: HC, first SA, SA>1).
% diff - relative difference describes the difference of the mean cortical thickness between two groups: HC and patients after SA. Significant p-values (p<0.05) are indicated in bold.
Significant differences in volume of left and right parts of hippocampus between study controls and all study patients are demonstrated in Table 4.
Table 4 The significant differences in mean volume of hippocampus parts between HC and all study patients
Hemisphere
|
Part of hippocampus
|
Mean volume (95% CI) in mm3
|
ANCOVA
age adjusted
|
|
|
HC (n=54)
|
All patients after SA (n=56)
|
% diff
|
|
|
|
|
1
|
2
|
1-2
|
F1.107
|
p
|
Left
|
|
|
|
|
|
|
|
ML
|
564.42 (545.31-583.55)
|
536.10 (517.28-554.93)
|
5.01
|
2.97
|
0.039
|
|
GC-DG
|
292.54 (282.38-302.68)
|
273.57 (263.63-283.52)
|
6.48
|
3.79
|
0.009
|
|
CA3
|
195.78 (188.04-203.51)
|
183.84 (176.24-191.43)
|
6.09
|
4.77
|
0.031
|
|
CA4
|
250.55 (241.90-259.22)
|
236 .85 (228.38-245.32)
|
5.46
|
5.05
|
0.027
|
|
HATA
|
58.31 (55.76-60.87)
|
52.94 (50.44-55.44)
|
9.20
|
4.46
|
0.004
|
Right
|
|
|
|
|
|
|
|
Subiculum
|
428.21 (411.15-445.27)
|
404..3 (387.15-420.91)
|
5.58
|
3.35
|
0.049
|
|
CA1
|
640.27 (616.07-664.45)
|
605.72 (581.90-629.54)
|
5.39
|
4.06
|
0.047
|
|
ML
|
574.35 (553.83-594.88)
|
545.01 (524.75-565.26)
|
5.10
|
3.09
|
0.047
|
|
GC-DG
|
303.14 (292.17-314.10)
|
287.19 (276.44-297.94)
|
5.26
|
4.25
|
0.042
|
|
HATA
|
61.01 (58.18-63.84)
|
56.54 (53.76-59.31)
|
7.32
|
5.02
|
0.027
|
HC, healthy controls; SA, Suicide attempt; ML, molecular layer; GC-DG, granule cell layer of dentate gyrus; CA, cornu amonis; HATA, hippocampus–amygdala transition area.
F, p – values are based on the pairwise comparisons among the means (two groups: HC and all patients after SA).
% diff - relative difference describes the difference of the mean hippocampus volume between two study groups: HC and patients after SA. Significant p-values (p<0.05) are indicated in bold.
Analysis of patients with history of first SA did not reveal significant differences in volume of hippocampus parts, in comparison to HC (Table 5). However, the comparison of controls to patients with SA>1 reported significant differences in mean volume of left and right parts of hippocampus volume, with 7.86 to 9.89% relative differences of the mean hippocampus volume between two groups.
Table 5 The significant differences in hippocampus part mean volume between the patients after first suicide attempt, repeated suicide attempts and study controls (first SA, SA>1 and HC)
Hemisphere
|
Part of hippocampus
|
Mean volume (95% CI) in mm3
|
ANOVA age adjusted
|
|
|
HC (n=54)
|
First SA (n=29)
|
Post-hoc
|
% diff.
|
SA>1(n=27)
|
Post-hoc
|
% diff.
|
|
|
|
|
1
|
2
|
1 vs. 2
|
1-2
|
3
|
1 vs. 3
|
1-3
|
F2.106
|
p
|
Left
|
|
|
|
|
|
|
|
|
|
|
|
GC-DG
|
292.54 (282.38-302.68)
|
277.34 (263.49-291.19)
|
0.247
|
5.19
|
269.52 (255.17-283.88)
|
0.032
|
7.86
|
3.79
|
0.026
|
|
HATA
|
58.31 (55.76-60.87)
|
53.32 (49.83-56.81)
|
0.072
|
8.56
|
52.54 (48.92-56.15)
|
0.033
|
9.89
|
4.46
|
0.014
|
Right
|
|
|
|
|
|
|
|
|
|
|
|
Subiculum
|
428.21 (411.15-445.27)
|
417.39 (394.12-440.67)
|
1.000
|
2.52
|
389.67 (365.54-413.80)
|
0.043
|
9.00
|
3.35
|
0.039
|
HC, healthy controls; SA, Suicide attempt; GC-DG, granule cell layer of dentate gyrus; HATA, hippocampus–amygdala- transition-area.
F, p – values are based on the pairwise comparisons among the means (three groups: HC, first SA, SA>1).
% diff - relative difference describes the difference of the mean hippocampus volume between two groups.
Significant p-values (p<0.05) are indicated in bold.
Post-hoc analyses revealed no significant within group differences in brain thickness and volume of parts of the hippocampus in patients after SA, when comparing first SA group (n=29) to SA>1 group (n=27).
The comparison of frontal and temporal cortex thickness and the volumes of hippocampus parts of all study patients with history of SA according to psychiatric diagnoses (major depressive disorder vs. other diagnosis), method of suicidal attempt (intoxication with drugs vs. physical suicidal act) and acute alcohol intoxication before SA (yes vs. no) did not reveal significant differences.