Table 1 Descriptive statistics for the sample

Total N (row %)

940

452 (48 %)

488 (52 %)

Parental social class N (col %)

p = 0.332

 Upper class

97 (10 %)

44 (10 %)

53 (11 %)

 Middle class

513 (55 %)

258 (57 %)

255 (52 %)

 Working class

330 (35 %)

150 (33 %)

180 (37 %)

Unemployment in the family, N (%)

173 (18 %)

78 (17 %)

95 (20 %)

p = 0.400

Parental mental health or alcohol problems, N (%)

70 (7 %)

40 (9 %)

30 (6 %)

p = 0.136

Parental interest in offspring’s studies, N (col %)

p = 0.940

 Probably very large

395 (42 %)

186 (41 %)

209 (43 %)

 Probably large

341 (36 %)

169 (37 %)

172 (35 %)

 Probably neither particularly large nor particularly small

144 (15 %)

69 (15 %)

75 (15 %)

 Probably small

43 (5 %)

21 (5 %)

22 (4 %)

 Probably very small

17 (2 %)

7 (2 %)

10 (2 %)

Help with homework assignment possible, N (col %)

p = 0.115

 Yes, always

282 (30 %)

144 (32 %)

138 (28 %)

 Yes, often

256 (27 %)

118 (26 %)

138 (28 %)

 Sometimes

271 (29 %)

134 (30 %)

137 (28 %)

 No, seldom

80 (8 %)

40 (9 %)

40 (8 %)

 No, never

51 (5 %)

16 (4 %)

35 (7 %)

Mean grades on leaving compulsory school, mean (SD)

3.10 (0.75)

3.26 (0.73)

2.96 (0.76)

p < 0.0001

 Average or below (≤3.0), N (col %)

407 (43 %)

170 (38 %)

237 (49 %)

p < 0.0001

 Above average (>3.0)

533 (57 %)

282 (62 %)

251 (51 %)

Latent trajectory of internalised mental health, N (col %)

p < 0.0001

 Very low stable

254 (27 %)

61 (14 %)

193 (40 %)

 Low stable

525 (56 %)

275 (61 %)

250 (51 %)

 Increasing

77 (8 %)

51 (11 %)

26 (5 %)

 Moderate stable

54 (6 %)

41 (9 %)

13 (3 %)

 High decreasing

30 (3 %)

24 (5 %)

6 (1 %)

Internalised mental health symptoms, mean (SD)

 At age 16

1.14 (1.39)

1.53 (1.62)

0.77 (0.99)

p < 0.0001

 At age 18

1.44 (1.84)

2.03 (2.06)

0.89 (1.40)

p < 0.0001

 At age 21

1.22 (1.71)

1.50 (1.89)

0.96 (1.47)

p < 0.0001

 At age 30

1.47 (2.13)

1.82 (2.33)

1.15 (1.88)

p < 0.0001

 At age 43

1.52 (2.30)

1.90 (2.53)

1.14 (2.00)

p < 0.0001