افکار و اعمال: داده های هنجاری در پرسشنامه پادوا از نمونه نوجوانان غیربالینی ایتالیایی

In the present study the structure of obsessive–compulsive phenomena in non-clinical adolescents was investigated by `The Padua Inventory' (PI). The PI is a self-report measure of obsessive and compulsive symptoms which is used in clinical and research settings. The use of PI in adolescents has been limited by the lack of normative data. Consequently, adolescent validation has both theoretical and practical implications. PI was administered to 566 normal Italian high school subjects, ranging in age from 15 to 18 years. The mean total score of PI and the mean score of `mental activities', `becoming contaminated' and `urges and worries' sub-scales points to significant differences between males and females. Females reported more obsessions and cleaning rituals than males. Males show more urges and fears than females. Moreover, our data underline that younger subjects get higher mean scores than older subjects in all scales.

Recent research has shown that the obsessive–compulsive disorder (OCD) is not so infrequent as was believed up to only 15 years ago. The numerous epidemiological studies carried out on adolescent subjects have produced a wide range of different prevalence values: Flament et al. (1988) found an OCD point prevalence of 1.0% (±0.5% S.D.) and a lifetime prevalence of 1.9% (±0.7% S.D.); Zohar et al. (1992) found a much higher point preference than Flament, namely 3.56% (±0.72% S.D.); Valleni-Basile et al. (1994) found a prevalence of 2.95%, higher for males (3.26%) than for females (2.64%). The results of the various studies are not always in agreement with regard to the expression of OCD symptoms in children and adolescents. Some authors consider that in most cases both obsessions and compulsions are present in both sexes ( Flament et al., 1988 ; Swedo, Rapaport, Leonard, Lenane & Cheslow, 1989; Riddle et al., 1990 ), while Zohar et al. (1992) found that 50% of adolescents with OCD display only obsessions. On the other hand, Valleni-Basile et al. (1994) , who studied young adolescents, found that compulsive symptoms prevailed in females and obsessive symptoms in males. Analysis of the literature ( Hollingsworth, Tanquay, Grossman & Pabst, 1980 ; Flament et al., 1988 ; Swedo et al., 1989 ; Rapaport, 1989 ; Burke, Burke, Regier & Rae, 1990 ; Riddle et al., 1990 ; Zohar et al., 1992 ; Valleni-Basile et al., 1994 ; Ravizza, Bogetto & Maina, 1997 ) reveals a high scatter of experimental data, particularly as far as onset, manifestation and trend of obsessive–compulsive symptoms are concerned, as well as both a quantitative and qualitative difference between the sexes. Furthermore, while considerable attention seems to be focused on the clinical manifestations of OCD, there is little apparent interest in the description and observation of obsessive and compulsive symptoms, above all in adolescent populations, although the epidemiological studies converge towards a prevalent onset of OCD in adolescence. Current models of OCD ( Rachman & de Silva, 1978 ; Rachman & Hodgson, 1980 ; Salkovskis, 1989 ) propose the existence of a continuum between normal intrusive thoughts and clinical obsessions which would enable the study of obsessive phenomena in non-clinical populations. Salkovskis's model begins with the assertion that clinical obsessions represent the extreme end of a continuum of normal, unpleasant, unwanted, intrusive cognition. The first aim of the present study is to highlight trends of obsessive and compulsive traits in non-clinical Italian adolescents, with special reference to their phenomenological expression both between the sexes and with variations in age. A number of a self reported measures of obsessive–compulsive symptoms have been developed, including the Maudsley Obsessive–Compulsive Inventory (MOCI, Hodgson & Rachman, 1977 ), the Leyton Obsessional Inventory (LOI, Cooper, 1970 ) and the Compulsive Activity Checklist (CAC, Philpott, 1975 ). The limitation of these measures consists in the difficulty in generalizing the results as each of them measures mainly only a small number of OCD sub-types. Sanavio (1988) has developed the Padua Inventory (PI), which has the advantage of allowing the most important types of obsessive–compulsive disorders to be measured. The PI is a 60-item self-report inventory, which measures intrusive thoughts, doubts, checking and cleaning behaviours, urges, repetitive thinking about low-probability dangers and recurrent repugnant images. Sanavio (1988) reported a factor analysis of data 967 non-clinical adults. Factor analysis identified 4 factors which were used to derive 4 sub-scales: (1) impaired control over mental activities; (2) becoming contaminated; (3) checking behaviours and (4) urges and worries. In recent years a number of studies have been carried out to analyse and verify the dimensional structure and the convergent and divergent validity of the PI ( van Oppen, 1992 ; Kyrios, Bhar & Wade, 1996). Some research ( Sternberger & Burns, 1990 ; van Oppen, 1992 ; Kyrios et al., 1996 ) points to a high internal consistency between total score and the various sub-scales (Cronbach's coefficient, α>0.80) but not for the `urges and worries' sub-scale, for which conflicting evidence has been found. For concurrent validity Sternberger & Burns, (1990) , van Oppen (1992) and Kyrios et al. (1996) found a high correlation (range 0.65–0.75) between total PI score and total MOCI and LOI scores. High correlation was found also for the sub-scales: between PI `mental activities' and MOCI `doubt' (range 0.68–0.69), between PI `becoming contaminated' and MOCI `cleaning' (range 0.53–0.74) and between PI `checking behaviours' and MOCI `checking' (range 0.67–0.84), while for the PI `urges and worries' scale it was found to be more difficult to trace concurrent validity using customary OCD assessment tools owing to the lack of an equivalent scale in these tests. The PI has also been used in a number of surveys concerning the phenomenology of the obsessive–compulsive disorder in several different countries: Italy ( Sanavio, 1988 ), Germany ( van Oppen, 1992 ; van Oppen, Hoekstra & Emmelkamp, 1993 ), USA ( Sternberger & Burns, 1991 ) and Australia ( Hafner & Miller, 1990 ; Kyrios et al., 1996 ). In the wake of these studies, our second aim is to increase the currently scant availability of normative data for the PI in adolescents.

The mean total and sub-scale scores (±S.D.) obtained from the sample were as follows: `total' 51.28 (±27.87 S.D.); `mental activities' 16.43 (±11.36 S.D.); `becoming contaminated' 12.20 (±7.25 S.D.); `checking behaviours' 8.16 (±5.75 S.D.) and `urges and worries' 3.75 (±4.92 S.D.). A series of one-way ANOVAs with sex and age as independent variables allowed significant differences to be observed. For the variable sex the following significant differences were observed with regard to both total score (F1,564=21.79; p<0.001) and the sub-scales `mental activities' (F1,564=50.23; p<0.001), `becoming contaminated' (F1,564=19.52; p=<0.001) and `urges and worries' (F1,564=3.89; p<0.05), while no differences were found for the sub-scale `checking behaviours'. Values and standard deviations are reported in Table 1 . Table 1. Mean and standard deviation for the sex variable Mental activities Becoming contaminated Checking behaviours Urges and worries Total X S.D. X S.D. X S.D. X S.D. X S.D. Male 13.26 10.17 10.91 6.50 7.81 5.76 4.15 5.48 46.04 26.80 Female 19.75 11.62 13.56 7.75 8.52 5.72 3.34 4.23 56.79 27.95 Table options These data indicate that females display higher mean scores than males in both the total score and in those of `mental activities' and `becoming contaminated'. Conversely, for the scale `urges and worries' males had higher mean scores. As regards the variable age the following significant differences were observed with regard to both total score (F4,561=7.32; p<0.001) and the sub-scales `mental activities' (F4,561=3.49; p<0.05), `becoming contaminated' (F4,561=4.52; p=<0.01), `checking behaviours'. (F4,561=3.23; p<0.05) and `urges and worries' (F4,561=6.82; p<0.001). Mean values and S.D. are reported in Table 2 . Table 2. Mean and standard deviation for the age variable Age Mental activities Becoming contaminated Checking behaviours Urges and worries Total X S.D. X S.D. X S.D. X S.D. X S.D. 15 years 18.37 13.02 13.28 6.99 10.00 6.69 5.86 7.32 60.68 32.24 16 years 17.78 11.71 13.44 8.62 8.69 5.87 4.38 5.57 55.90 28.23 17 years 16.72 10.53 12.02 6.44 8.09 5.13 3.83 4.32 51.53 25.43 18 years 14.20 11.15 10.75 6.04 7.24 5.87 2.54 3.70 43.89 27.32 Table options A preliminary analysis indicates a decreasing trend in mean values with increasing age. Post-hoc analysis of the total scale using the Duncan Test shows that the 15 year old subjects score higher on average than 17 year olds (p<0.05) and 18 year olds (p<0.001). It also emerges that 16 year olds score higher on average than 18 year olds (p<0.01). As far as the `mental activities' scale is concerned, 15 and 16 year old adolescents are found to score higher on average than 18 year olds (p<0.05 and p<0.05, respectively). Similar results were found for the `becoming contaminated' scale (p<0.05 and p<0.05). For the `checking behaviours' scale, statistical analysis attributed significance to the differences between the mean scores of the 15 year olds with respect to 17 and 18 year olds (p<0.05 and p<0.01). Lastly, for the scale `urges and worries' it was found that 15 year olds score significantly higher on average than 16, 17 and 18 year olds (p<0.05, p<0.01 and p<0.001). Moreover, 16 year olds score higher on average than 18 year olds (p<0.05). Sex–age interaction was found to be non-significant