Introduction 1996 2000 1997 2004 1995 1995 1990 1998 1997 2000 1999 1996 2003 2004 2005 1999 2001 2002 2005 1991 1999 2003 2003 2005 2006 2000 2002 1997 1998 2003 The aim of the present study was to investigate homotypic and heterotypic longitudinal patterns of symptoms of separation anxiety disorder, generalized anxiety disorder, social phobia, panic disorder, and obsessive compulsive disorder in young adolescents from the Dutch general population. For this purpose, individuals from a community sample, who were assessed for the first time when they were aged 10 to 12 years, were followed up across a period of two years. At both assessments, anxiety symptoms were assessed with a self-report questionnaire. Given mixed results of previous studies, we did not formulate specific hypotheses regarding the level of homotypic or heterotypic continuity of different types of anxiety. Methods Sample and procedure 2005 N N SD 2005 2005 2000 p p R Table 1 RCADS items SAD SoPh Fears being alone at home Worried when does poorly at things Scared to sleep alone Worried when somebody angry Scared to sleep away from home Worried will do badly at school Fears being away from parents Worried about mistakes Worried in bed at night Worried what others think Trouble going to school Scared to take a test Afraid of being in crowded places Worried might look foolish  Afraid to talk in front of class  Afraid to look foolish in front of people GAD PD Worried something awful will happen to family Suddenly trouble breathing without reason Worried bad things will happen to self When has a problem, feels shaky Worried something bad will happen to self Suddenly trembling, shaking without reason Thinks about death Suddenly dizzy, faint without reason Worried about things When has a problem, stomach feels funny Worried about what will happen When has a problem, heart beats really fast  Suddenly feeling scared without reason  Suddenly heart beats too fast without reason  Worried suddenly get scared without reason OCD  Can’t get silly/bad thoughts out of head  Keeps checking  Has to think thoughts to stop bad events  Has to do things over and over again  Has to do things just right to stop bad events  Bothered by bad/silly thoughts or images  Measures The Revised Child Anxiety and Depression Scale RCADS 2000 1997 1 2000 2006 2004 Statistical analyses First, to obtain information regarding comorbidity between different types of anxiety problems in the study sample, correlations among wave 1 RCADS scale scores were computed for each sex. Then, Pearson correlations were computed between wave 1 and wave 2 RCADS scale scores, separately for each sex group. Correlations provide insight in the associations between measures. However, by just computing correlations, it can not be judged if continuity is homotypic or heterotypic. For instance, the magnitude of a correlation between wave 1 SAD and wave 2 SoPh scores depends on the correlation between wave 1 SAD and wave 1 SoPh scores. The higher correlations between wave 1 SAD and wave 1 SoPh are, the higher the correlation between wave 1 SAD and wave 2 SoPh will be. In other words, if assessment of continuity would solely be based on correlations, comorbidity at wave 1 would artificially inflate estimations of the extent of heterotypic continuity between wave 1 and wave 2. R 2 Second, it was assessed which part of continuity in anxiety problems was specifically heterotypic. For this purpose, for scores on each of the five RCADS scales at wave 2, a set of regression analyses was conducted, with wave 2 RCADS SAD, GAD, SoPh, PD, and OCD scores as dependent variables. These analyses were conducted to investigate how much of the variance in a specific RCADS scale score at wave 2 was not accounted for by its own counterpart at wave 1, but instead, by the other wave 1 anxiety scale scores. We will now describe the regression analyses that were conducted for wave 2 SAD. Those for GAD, SoPh, PD, and OCD were similar. In the first block of the analyses, wave 1 SAD scores were entered as predictor. Then, in the second block, scores on wave 1 GAD, SoPh, PD, and OCD scales were added, to see how much of the variance in wave 2 scores was specifically predicted by other RCADS scales at wave 1. This variance reflects specific heterotypic continuity. In the third block, sex was added. 1988 2 Results SD SD SD SD SD SD SD SD SD SD 2 1988 r r r Table 2 Correlations among wave 1 RCADS scale scores  Wave 1 RCADS scale Wave 1 RCADS scale GAD b/g SoPh b/g PD b/g OCD b/g SAD .52/.58 .52/.52 .51/.52 .47/.51 GAD — .59/.54 .55/.54 .58/.58 SoPh  — .56/.55 .54/.53 PD   — .61/.61 OCD    — Note Table 3 Correlations between wave 1 and wave 2 RCADS scale scores Wave 1 RCADS scale Wave 2 RCADS scale  SAD b/g GAD b/g SoPh b/g PD b/g OCD b/g SAD .30/.38 .23/.32 .35/.29 .28/.27 .21/.25 GAD .27/.27 .34/.38 .29/.28 .22/.25 .23/.27 SoPh .29/.29 .35/.29 .42/.41 .29/.28 .25/.25 PD .22/.29 .25/.31 .24/.27 .32/.42 .25/.29 OCD .23/.30 .25/.32 .28/.27 .27/.32 .31/.37 Note 3 Table 4 Specific homotypic continuity (prediction by target scale). Prediction of wave 2 RCADS scale scores by wave 1 scale scores and sex  Wave 2 RCADS scale  SAD GAD SoPh PD OCD Wave 1 predictors R 2 F p 1 R 2 F p 1 R 2 F p 1 R 2 F p 1 R 2 F p 1 Non-target scales (block 1) .119/69.68/.000 .150/91.19/.000 .132/78.35/.000 .126/74.19/.000 .106/61.22/.000 Target scale (block 2) .050/123.57/.000 .023/58.06/.000 .069/178.54/.000 .037/90.39/.000 .025/59.20/.000 Sex (block 3) .023/58.92/.000 .036/93.32/.000 .037/100.65/.000 .032/81.21/.000 .009/21.34/.000 * .001/2.06/ns .002/5.12/.024 .000/.81/ns .009/23.81/.000 .002/5.38/.020 Models for girls/boys separately in case of interaction target-scale*sex  Girls   Non-target scales (block 1) — .145/44.70/.000 — .128/38.75/.000 .109/32.82/.000   Target scale (block 2) — .024/31.06/.000 — .060/77.54/.000 .038/47.13/.000  Boys   Non-target scales (block 1) — .136/39.32/.000 — .107/29.72/.000 .089/24.41/.000   Target scale (block 2) — .018/20.85/.000 — .020/22.82/.000 .021/23.05/.000 Note R 2 4 5 4 5 * 4 R 2 R 2 Discussion 4 5 2000 1999 1996 2003 Separation anxiety 2000 2006 Table 5 Specific heterotypic continuity (prediction by non-target scales). Prediction of wave 2 RCADS scale scores by wave 1 scale scores and sex  Wave 2 RCADS scale  SAD GAD SoPh PD OCD Wave 1 predictors R 2 F p 1 R 2 F p 1 R 2 F p 1 R 2 F p 1 R 2 F p 1 Target scales (block 1) .391/373.39/.000 .375/337.53/.000 .436/483.57/.000 .380/347.98/.000 .337/263.45/.000 Non-target scale (block 2) .020/83.77/.000 .042/86.59/.000 .013/103.79/.000 .023/80.00/.000 .027/82.20/.000 Sex (block 3) .027/81.60/.000 .041/90.95/.000 .040/107.45/.000 .028/82.80/.000 .012/55.90/.000 Note R 2 Generalized anxiety 2001 Social phobia 2001 Panic 4 1997 2005 1999 2005 1981 Obsessive compulsive disorder 2001 2002 Practical implications 2001 2001 2001 2003 2001 1991a b 2004 2005 1999 2001 Limitations 1994 2004 Since different informants may provide different information, this study would have been more valuable if information regarding symptoms of different types of anxiety would also have been gathered from parents or teachers. Unfortunately, such information was not available. Conclusion In the present study’s sample of young adolescents from the Dutch general population, evidence for homotypic continuity was found, especially for symptoms of separation, social, and generalized anxiety, and for symptoms of panic disorder in girls.