The current work looks to examine the underpinnings of anhedonic depression - i.e. depression associated with an inability to feel pleasure. This is an important group and little is know about the factors that characterise and are important for this outcome. The work will use detailed questionnaires to examine the likely presence or absence of this presentation in ALSPAC participants and there will be extremely detailed followup of a sub-set of participants likely to have this condition. This work will be in parallel with that in a study called NESDA in The Netherlands - providing important replication and sample size.