COSTO DIRECTO

P c r c e n t .(X) 4.00 8.00 1200 16.00 20.00 Maleathletes Femaleatiiletes Male comparison Female comparison 200 6.00 10.(X) 14.00 18.00 2200

G en der com parisons

Independent t-tests (2 tailed) were carried out to determ ine the location of significant gender differences both betw een and w ithin the athlete and reference populations. Results established there w ere no significant differences betw een any sport and gender group (gymnastics, t = -.11, p = n.s.; swim m ing, t = -.2 0, p =

n.s. ; tennis, t = -.34, p = n.s. ). N or was there a significant difference betw een male and female athletes for the sports population as a whole (t = -.70, p = n.s. ).

H ow ever, w ith in the com parison group, females had significantly higher scores th an m ales (t = -3.67, p <.001).

Group com parisons

As there w as no significant difference betw een male and female athletes their num bers w ere combined in each of the three sports groups. A one-w ay analysis of variance w as used to determ ine w hether there w as a significant difference betw een the depression scores of the four sports groups. Results indicated there w as no significant difference betw een the sports (F (3^ 437) = 1.89, p

= n.s.). The effect group m em bership may have upon DSRS scores w as calculated by com paring scores of male and female athletes' w ith those of the com parison population. M embers of the athlete group had significantly lower DSRS scores (ANOVA, F (3^ 914) = 42.6, p < .001). Post hoc identification of pairw ise differences

indicated m ale athletes ( % = 5.86) had significantly lower depression scores than m ale or females from the com parison population (x = 7.89 and 9.32 respectively (all p < 0.5). Female athletes (6.01) also had lower scores than either m ales or fem ales from the com parison population (all p < 0.5).

Further analysis of the DSRS data for the athlete group established that there w as no significant effect of social class, as assessed by the occupational status of the head of the household (OPCS, 1981), on depression scores (F (i, 42 5) = .352, p

= n.s.).

Effects of age on depressive symptomatology

M ean DSRS scores stratified by age for the athlete and com parison populations are show n in Table 30. Previous research has indicated a positive

linear relationship between increasing age and depressive sym ptomatology. The data from this study do not tend to follow this age gradient. For athletes the scores gradually decline w ith age - from 8.3 at age 9 years to 5.8 at age 18 years. Scores for children from the comparison population suggest a bi-modal distribution, higher depression scores occurring in childhood - ages 9 and 10 (mean scores 9.9 and 8.1 respectively) - and late adolescence - ages 17 and 18 (mean scores 9.0 and 10.0).

T a b l e 30: E ffe c t o f a g e o n m e a n D S R S s c o r e s 22 9.9 (4.1) 16 8.3 (2.2) 33 8.1 _{^ ^ )} 2 8 7.0 (3.5) I * ' ' ' -;' : 12 7 .8 P 5 ) 74 6.4 (3.6) 1 2 '% " ': '': : 37 7.6 21 5 .7 (2.7) 44 7.4 (3.8) 103 5.6 (2.7) i * 114 8.5 _{0 ^ )} 14 6 .6 (4.3) 83 9.0 (4.3) 94 5 .6 (3.4) 16 8 .3 ^ ^ ) 14 4.3 (1.6) 78 9.0 (4.4) 72 5.9 (3.6) 38 10.0 (4.2) 5 5.8 (2.7)

Linear regression was used to examine the association between age and depressive sym ptomatology. For the comparison population the association betw een the two variables approached significance - DSRS scores increasing w ith age - (F (1^ 475) = 3.2, R' = .01, p = .07) but accounted for virtually none of the

variance. For the athletes there was a significant inverse relationship betw een age and DSRS scores (F (i^ 439) = 8.1, R' = .02, p = .005). The associations can be seen

Figure 6

DSRS score at each age point for athlete and comparison populations

M e a n D S i s c o r e 1 1 1 O' Comparison 9 8 7 6 Athletes 5 4 10.00 11.00 12.00 13.00 14.00 15.00 16.00 17.00 18.00 Age (years)

Prevalence of depressive symptomatology

Children scoring 15 or above on the DSRS are classified as possible cases of depressive disorder (Birleson 1987). In the present study a significantly greater proportion of cases came from the comparison population (%2 = 46.82, p < .0001). For females, 2.3% of the young athletes (5 children) and 14.5% (35 children) from the com parison population were identified as cases. For males, 0.9% of the young athletes (2 children) and 5.5% (13 children) from the comparison population scored above the cut-point. The following table illustrates the distribution of scores above and below the cut- point.

Table 31: A comparison of high versus low depression scores by group

A t h l e t e s C o m p a r i s o n p o p u l a t i o n

$cor« < 15 Ino case) Score ^ 15 (case) N (%) 212 97.7 5 23 N (%) I 222 99.1 : 2 04 i N (%) 206 85.5 35 14.5 N (%) 223 94.5 13 5.5 Total 217 100 224 100 : 241 100 236 100

Controlling for the effect of age on depressive symptomatology

It is clear from the above analyses that male and female athletes have significantly low er depression scores than children from the com parison

population. H ow ever, it is possible that rather than this finding reflecting some non-specific group effect on depressive sym ptomatology, it is an artefact of age. It is w ell established that depressive sym ptom s increase w ith advancing age

(Rutter, 1988). As the com parison population is significantly older than the athlete group (see the section on the age distribution of the sam ple above) by several m onths, it is possible the difference in depression scores is due to this factor. To elim inate this possibility the num ber of athletes and com parison children in each age band were matched. M atching w as achieved by random ly excluding children from either the athlete or com parison populations so th at the num bers in each age group w ere approxim ately equal.

The random ising procedure

A 2 (group: athlete x controls) by 9 (age group: 9 to 18 years) contingency table established the num ber of subjects needed to be excluded in each age-band, in order to balance the sam ple population. Once the num bers had been

identified, cases for exclusion were selected using a table of random num bers following the procedure suggested by Kahn & Sempos (1989). Tables are laid out in colum ns of tw o-digit num bers, w ith two columns providing four digits which corresponded to the size of the identification num bers of the children taking p art in the study. If the num ber in the table corresponded to the identification

num ber of a child of the right age, belonging to the right group, he or she was excluded from the sample.

Characteristics of the random population

The new sam ple com prised 675 children, 312 athletes and 331 children from the com parison population. There was no significant difference in age betw een the athlete ( x = 14.1 years) and comparison ( x = 14.1 years) populations (t = -.16, p = n.s). DSRS scores w ere available for the whole sample. There w ere no m issing data. M ean DSRS scores for the athlete and com parison groups are show n in Table 32.

Table 32: Mean DSRS symptomatology score by group and gender for the random sample

Female Male Total

fo o tb a ll - -- -- 43 5.1 3.1 43 5.1 3.1

GyimtasHcs 55 6.4 3.8 27 5.7 3.9 82 6.2 3.8

Swiimmiig 41 6.4 4.0 36 5.6 3.6 77 6.1 3.8

Temiis 60 5.6 2.9 50 5.8 3.4 110 5.7 3.1

Coûiparisoit populalion 181 8.9 4.6 150 7.8 4.0 331 8.4 4.4

The means for this sample are almost the same as those reported for the whole sam ple population (see Table 16 above). Analysis of variance conducted on these data established main effects for both gender (F (i^ 627) = 6.0, p = .02) and group (F (4^ 627) = 16.0, p < .001). For this population there was no significant age

effect on DSRS scores (F (9^ 627) = h2, p = n.s.).

Gender com parisons

There were no significant differences between any sport and gender group (gymnastics, t = -.82, p = n.s.; swimming, t = -.93, p = n.s. ; tennis, t = .31, p = n.s. ). Nor w as there a significant difference between male and female athletes for the sports population as a whole (f - m = 0.3, t = -.70, p = n.s. ). However, within the com parison group, females had significantly higher scores than males (f = -2.29, p

= .02).

Group com parisons

As there was no significant difference between male and female athletes their num bers were combined in each of the three sports groups. A one-w ay analysis of variance was used to determine w hether there was a significant difference between the depression scores of the four sports

groups. Results indicate there was no significant difference between the four sports (F (3, 308) = .98, p = n.s.). The effect group membership may have upon

w ith those of the comparison population. Members of the athlete group had significantly lower DSRS scores (F (3^ 639) = 24.8, p < .0001). Post hoc identification

of pairw ise differences indicated male athletes ( x = 5.6) had significantly lower depression scores than males or females from the comparison population (% = 7.8 and 8.9 respectively (all p < 0.5). Female athletes {x = 6.1) also had lower scores than either males or females from the comparison population (all p < 0.5).

Prevalence of depressive symptomatology

Using the cut-point previously described, a significantly greater proportion of cases came from the comparison population (%2 = 25.8, OF. 3, p < .0001). For

females, 2.6% of the young athletes (4 children) and 12.7% (23 children) from the com parison population were identified as cases. For males, 1.3% of the young athletes (2 children) and 4.7% (7 children) from the comparison population scored above the cut-point. The following table illustrates the distribution of scores above and below the cut- point.

Table 33: A comparison of high versus low depression scores by group Athletes Comparison group

n % mw n n

Score < 15 (no case) 152 97.4 154 98.7 i\ 158 87.3 143 95.3

Score ^ 15 (case) 4 2.6 2 1.3 ! 23 12.7 7 4.7

T o à ï 156 100 156 100 1: 181 100 150 100

Results from this sample, where the possible effects of age were rem oved, suggest the significant difference in depression scores is a

function of group membership rather than chronological age. Because of this finding the larger sample will be used throughout the rem inder of the analyses.