Table 2.

Summary of themes and subthemes that emerged from the data.

Main themes	Sub-theme	Sub-sub-themes
The relationship between mood and fatigue	Causality	Fatigue predating low mood
Mechanism of the CFS/ME-mood relationship	Restricted activity	‘Vicious cycles’; a complex relationship whereby symptoms (and/or management plans) initially reduce or impair activity. A cyclical relationship then develops between restricted activity, mood and negative/anxious thoughts.
	A changing role within social environments and wider systems	Symptoms (and/or management plans) cause changes within friendship groups, families and education system. Negative perceptions, for example, loss and low mood develop a cyclical relationship.
	Loss	Being a teenager, Education, Social life, Family, Self-identity, Spontaneity
Managing mood	Individualised approach	CBT, activity management, medication, other helpful strategies

CFS/ME: chronic fatigue syndrome/myalgic encephalomyelitis; CBT: cognitive behavioural therapy.