Aim: To identify whether pubertal timing moderates longitudinal associations between parent substance use, parent-child relationship quality and adolescent substance use.

Background: Early initiation of substance use has been associated with a more rapid progression to heavier use and abuse (Spear, 2000), has short- and long-term health implications (van den Bree, 2005) and can impact on individual and others' welfare through associations with increased risky behaviour (Patton et al., 2004). Understanding the psychosocial risk mechanisms that lead some adolescents to earlier initiation and heavier use of substances is arguably central to reducing the existing public health burden presented by frequent and/or excessive drinking and smoking. The quality of family relationships, parents' own substance use and the timing of pubertal maturation relative to one's peers are risk factors for substance use in adolescence. The potential interplay between these risk factors in influencing the use of cigarettes and alcohol in early to mid-adolescence is not well understood.

Children from homes characterised by poor family functioning and by parents own heavy substance use are at increased risk of substance use (Hawkins, Catalano & Miller, 1992; Engels et al., 2004). Family relationships that are non-supportive or characterised by conflict can undermine adolescents' ability to regulate their behaviour in a goal-oriented way, with self-regulation linked in turn to substance use (e.g. Brody & Ge, 2001). On the other hand, adolescents who smoke or drink regularly may incur parents' disapproval that in turn is linked to decreased expressions of warmth and affection by parents and increased conflict (Shelton et al., 2008).

The timing of the pubertal transition (compared to same-sex, same-age peers) is theorised to be an important determinant of the relationship between pubertal maturation and psychopathology (Graber et al., 1997). Early maturing adolescents may be more prone to experiencing difficulties because they are less well prepared for pubertal change (Peskin, 1973). Early pubertal timing is associated with the increased use as well as abuse of substances (e.g. Graber et al., 1997; Lanza & Collins, 2002; Orr & Ingersoll, 1995). Other studies, however, have also shown that late-maturing males begin to drink earlier and to smoke more than on-time maturing males (Graber et al., 1997; (Bratberg et al., 2007).

Early maturation is theorised to sensitise children to variations in parent mood and behaviour, which heightens risk for psychological adjustment problems (e.g. Ge et al., 2002). In addition, while pubertal maturation has been associated with negative emotions among adolescents, this emotionality may be partly attributed to parents who are not perceived to be sensitive to the adolescent's needs (Paikoff & Brooks-Gunn, 1991). Findings suggest a potential disparity between parent and adolescent expectations about the timing of developmental tasks in the families of off-time maturing boys and girls.

While previous research has independently identified early maturation, parent substance use and parent-child relationship quality as risk factors for adolescent substance use, it is not clear how domains of family functioning might interact with the timing of pubertal development to influence use of cigarettes and alcohol. In our analyses based on Addhealth data we found that the longitudinal association between parent-child relationship quality (assessed in 1995) and alcohol use (assessed one year later in 1996) was stronger for early than late maturing girls, in addition, we also found gender differences in the moderating influences of pubertal development on the associations between relations with the parents and adolescent substance use (Shelton and van den Bree, submitted).

The aim of the proposed research is to investigate in ALSPAC the transactional nature of longitudinal associations between the quality of parent-child relations, parent substance use and adolescent cigarette and alcohol use and to assess whether any such relationships are moderated by the timing of pubertal maturation as well as to further explore potential gender differences.

Analyses will involve structural equation models using maximum likelihood estimation in LISREL (Joreskog & Sorbom, 1996).

Data which we would like to use for this project are:

103 months of life (frequency of use of different alcoholic beverages)

115 months of life (parental awareness of child alcohol use)

140 months of life (parental awareness of child alcohol use)

157 months of life (frequency of use of different alcoholic beverages)

8 Years old Ever drunk without permission (antisocial behaviour questionnaire)- personal interview

10 Years old Ever drunk without permission (Antisocial behaviour questionnaire)- personal interview

11 Years old Got very drunk (sensation seeking questionnaire) - personal interview based

13 Years old Several question related to alcohol use, frequency of use, pattern of use, binge drinking, getting drunk, age started, usage by friends.

14 Years old Several question related to alcohol use, frequency of use, pattern of use, binge drinking, getting drunk, age started, usage by friends .

15 Years old Several question related to alcohol use, frequency of use, pattern of use, binge drinking, getting drunk, age started, usage by friends.

115 months of life (parental awareness of child cigarettes use)

140 months of life (parental awareness of child cigarettes use)

167 months (cigarettes use attitude) - questionnaire based

8 Years old Ever smoked - personal interview based

10 Years old Ever smoked - personal interview based

13 Years old Several question related to cigarettes smoking, frequency of use, pattern of use, age started, usage by friends.

14 Years old Several question related to cigarettes smoking, frequency of use, pattern of use, age started, usage by friends.

15 Years old Several question related to cigarettes smoking, frequency of use, pattern of use, age started, usage by friends.

Parental reports

97 months of life Cigarettes use/ Partner smoking/ Alcohol use

110 months of life Drug use/ Partner smoking/ Partner drinking

134 months of life Cigarettes use/ Partner smoking

145 months of life Cigarettes use/ Partner smoking/ Partner drinking

97 months of life Parent to child interaction (Enjoyment)

Partner's parent to child interaction (Parental enjoyment)

Parent to parent interaction (aggression, affection)

110 months of life Partner's parent to child interaction (Parental enjoyment)

Parent to parent interaction (activities together, satisfaction, rows, warmth, authority)

145 months of life Partner's parent to child interaction (Parental enjoyment)

Parent to parent interaction (activities together, satisfaction, rows, warmth, authority)

169 months of life Parent to child interaction (Parental involvement in child social life and parental awareness)

Timing of variables of pubertal development SPECIFIC CHILD BASED QUESTIONNAIRE "Growing and Changing" (including Tanner assessments).