Table 1 Descriptives of research variables for the total NSSI disorder sample, BPD and no-BPD Group, respectively

N

%

N

%

N

%

Gender (N, % = Female)

151

91.0

90

96.8

61

83.6

M

SD

M

SD

M

SD

Age

15.04

1.34

15.29

1.29

14.73

1.35

Number of BPD criteria

4.72

2.00

6.16

1.22

2.89

1.10

BPD diagnostic criteria

N

%

N

%

N

%

 Fear of abandonment

57

34.3

47

50.5

10

13.7

 Unstable relationships

96

57.8

77

82.8

19

26.0

 Identity disturbances

64

38.6

55

59.1

9

12.3

 Impulsivity

42

25.3

35

37.6

7

9.6

 Self-harm/Suicidality

164

98.8

93

100.0

71

97.3

 Affective instability

118

71.1

88

94.6

30

41.1

 Inner emptiness

103

62.0

70

75.3

33

45.2

 Inappropriate anger

74

44.6

58

62.4

16

21.9

 Paranoia/Dissociation

66

39.8

50

53.8

16

21.9

Adverse Childhood Experiences

N

%

N

%

N

%

 Antipathy Mother

64

38.6

43

46.2

21

28.8

 Antipathy Father

68

41.0

44

47.3

24

32.9

 Neglect Mother

36

21.7

20

21.5

16

21.9

 Neglect Father

56

33.7

37

39.8

19

26.0

 Parental Loss

54

32.5

33

35.5

21

28.8

 Physical Abuse

42

25.3

29

31.2

13

17.8

 Sexual Abuse

43

25.9

33

35.5

10

13.7

Current social functioning

M

SD

M

SD

M

SD

 Parent relationship Quality

2.91

1.04

2.82

1.01

3.02

1.08

 Peer Relationship Quality

3.10

.94

3.15

.92

3.04

.96

Type of non suicidal self harm

N

%

N

%

N

%

 Cut or carve skin

165

99.4

92

98.9

73

100.0

 Skin scraping

91

54.8

52

55.9

39

53.4

 Wound picking

82

49.4

47

50.5

35

47.9

 Skin burning

65

39.2

43

46.2

22

30.1

 Deliberate self-hitting

54

32.5

33

35.5

21

28.8

 Biting

51

30.7

30

32.3

21

28.8

Severity of Self harm

N

%

N

%

N

%

 In need for treatment after self-harm

44

26.5

31

33.3

13

17.8

Frequency of Self harm

M

SD

M

SD

M

SD

 Thoughts on self-harm last month

22.35

45.66

26.43

58.97

17.11

16.55

 Self-harming behaviours last month

9.22

12.71

9.80

14.79

8.49

9.46

Reported reason for self-harm

N

%

N

%

N

%

 Mental State

138

83.1

77

82.8

61

83.6

 Dispute with parents or family

114

68.7

47

50.5

48

65.8

 School distress

78

47.0

42

45.2

36

49.3

 Dispute with friends

74

44.6

47

50.5

27

37.0

 Dispute with best friend

42

25.3

28

30.1

14

19.2

 Bullied/eviction

46

27.7

26

28.0

20

27.4