Table 1 Comparison of the Parental Bonding Inventory (PBI), Eysenck Personality Questionnaire (EPQ), 20-item Toronto Alexithymia Scale (TAS-20), and Chinese Health Questionnaire (CHQ) among the three groups: deliberate self-harm (DSH), intention to suicide (ITS), and control participants (n = 171)

PBI

 Paternal control and protection

8.86 (8.62)

−10.18 (5.95)

0.94 (9.27)

F = 101.05

Control > ITS MD = −1.66 p = 0.705

p < 0.001

DSH < ITS MD = 9.48 p < 0.001

Control > DSH MD = 11.15 p < 0.001

 Maternal control and protection

10.47 (9.52)

−3.62 (5.64)

7.28 (10.16)

F = 51.56

Control > ITS MD = 1.22 p = 0.801

p < 0.001

DSH < ITS MD = 10.17 p < 0.001

Control > DSH MD = 8.96 p < 0.001

EPQ

 Extraversion

7.62 (3.76)

6.47 (4.24)

4.95 (4.11)

F = 5.19

Control > ITS MD = −2.82 p = 0.001

p = 0.007

DSH > ITS MD = −0.47 p = 0.858

Control > DSH MD = 2.82 p = 0.001

 Neuroticism

3.44 (3.34)

4.91 (3.55)

7.37 (3.89)

F = 14.34

Control < ITS MD = 4.56 p < 0.001

p < 0.001

DSH < ITS MD = 0.12 p = 0.984

Control < DSH MD = −4.44 p < 0.001

TAS-20

 Difficulty identifying feelings

17.00 (6.35)

19.83 (6.75)

24.47 (7.26)

F = 14.45

Control < ITS MD = 8.33 p < 0.001

p < 0.001

DSH < ITS MD = 0.93 p = 0.782

Control < DSH MD = −7.40 p < 0.001

 CHQ

2.66 (2.87)

3.99 (3.34)

6.13 (3.77)

F = 13.19

Control < ITS MD = 3.87 p < 0.001

p < 0.001

DSH < ITS MD = 0.41 p = 0.818

Control < DSH MD = −3.46 p < 0.001