Objective Apathy is a disorder of diminished motivation. It occurs in several neurological pathologies and is associated with pervasive and disadvantageous effects on daily functioning. It has been observed to occur transiently in a proportion of children undergoing surgery for posterior fossa tumours. In this study we examined prevalence, associations and predictors of apathy in adult survivors of an early childhood posterior fossa brain tumour (PFT).

Method 117 adult survivors of an early childhood PFT and 62 of their siblings were assessed an average of 32 years (range 18–53) after survivors' initial tumour diagnosis, using the Marin Apathy Evaluation Scale (AES), the Weschler Abbreviated Scale of Intelligence and the Composite International Diagnostic Interview.

Results AES reached or exceeded a criterion score for diagnosis of apathy in 35% of survivors compared with 18% of a sibling comparison group. In survivors, apathy was associated with decreased likelihood of being in employment or education, and lower full scale IQ score. Apathy was not related to ICD-10 current diagnoses of depression. While in siblings, apathy was more common in males than in females, among survivors there was a trend for this imbalance to be reversed.

Conclusion Clinically significant apathy occurs relatively commonly in adult survivors of an early childhood PFT, and it does not result from increased levels of depression. Clinicians should be aware of this association and future research should clarify which tumour or treatment-related variables are implicated in increasing this risk of apathy.