Aims . The aim of this proposal is to determine whether there is an association between mitochondrial (MT) copy number and measures of chronic stress (particularly early childhood chronic adversity). This analysis will only be possible using the ALSPAC sample included in the UK 10K project as I need sequence data to answer this question.

Hypotheses

Based on preliminary data from a case control study of major depression I think that early childhood chronic adversity elevates MT copy number, through an unknown mechanism. From DNA sequence data I have observed that in both cases and controls there is correlation between the following measures and MT copy number: neuroticism, number of stressful life events, childhood sexual abuse.

Variables

A meausure of susceptibility to stress (neuroticism), number of stressful life events (we used the 16 item stressful life events questionnaires), and measures of childhood abuse (we interrogate specifically non-genital, genetal and intercourse). Meaures of MT copy number are obtained from the numbers of reads mapping to the reference MT genome, normalized by the reads mapping to the autosomes (I use read data only from one chromosome to get this measure).

Outcomes

A linear model including age and weight, is used to predict MT copy number.

Confounds

As far as we know, age and weight are the only relevant confounds.