Background Human papillomavirus (HPV) is one of the most common sexually transmitted infections and can be prevented by vaccination. The purpose of this study is to gain a better understanding, by analysing interview responses of adolescents and parents, of how adolescent sexual behaviour is approached in families, how widespread knowledge about HPV is in Andalusia, the autonomous region with the lowest vaccination rate in Spain, as well as to learn more about the interviewees’ position regarding vaccination. Methods A qualitative study by means of 15 focus groups of adolescents (N = 137, aged 14–17 years) and five focus groups of parents with children of those ages (N = 37) was conducted in the provinces of Granada, Seville and Jaén (Andalusia, Spain). The audio data were transcribed verbatim, coded and analysed thematically using NVIVO-10 software. Results There were three major results: (1) There is a lack of communication between adolescents and parents regarding sexual behaviour; (2) In both groups, scarce knowledge about HPV and vaccination was found; (3) Parents mistrust vaccination due to a lack of qualified and verified information about its benefits. Conclusions Healthy adolescent sexual behaviour is aided by communication within the family. Families need more information based on the evidence about HPV and vaccination. Health professionals are a key element in this process.

Background To learn about the experiences and opinions of adolescent non-consumers and regular cannabis users about cannabis use and the factors that determine its use, using the I-Change explanatory model as a basis. Methods Qualitative methodology with a content analysis was used. Focus groups were conducted with adolescents who were non-regular cannabis users (those who had not tried cannabis or had only experimented with it before) and semi-structured interviews were conducted with adolescent and young adult in recovery who were in a detoxification program. A deductive analysis of the audio-recorded and transcribed interviews was performed, using the domains of the I-Change Model as a reference. Results Personal problems, social problems or family problems can lead to cannabis use. There was a lack of knowledge and low risk perception about consumption of this drug. There are other factors that influence consumption, the perception of advantages, such as the feeling of freedom and the influence of the peer group. The consumption of this substance in girls is changing, becoming more and more equal to that of boys. The family has an important role to play in preventing drug use. Conclusion Knowledge of these factors is of vital importance as a prior step to the development of efficient intervention measures adjusted to the needs identified and the characteristics of the population.