Teen Focus 3 (TF3) follow-up of the ALSPAC offspring will begin in October 2006. Core funding for that clinic assessment has been obtained from the MRC and Wellcome Trust and the clinic procedures will focus on obtaining high quality measurements on the children that are funded from that grant. However, since the offspring are still of an age where parental consent will be required the vast majority will be attending the clinic with one of their parents/guardians. Some parts of the TF3 assessment require the parent/guardian NOT to be present and from experience with the TF1 and TF2 assessments there are other parts of the assessment where the parent does not stay with their offspring. Thus, there is an opportunity to complete some assessments with the parents/carers who are attending their offspring's assessment at TF3. This proposal is concerned with the scientific rationale and procedures for undertaking opportunistic assessments on the parents/carers who will be attending with their offspring at TF3.