• Dementia
• head injury
• cognitive neuropsychology
• rehabilitation
• neuropsychiatry
• psychiatry
• subarachnoid haemorrhage
• rehabilitation

When asked to see a patient who is deteriorating rather than getting better over time since a head injury, the clinician will need to rule out complications of the head injury, such as a subdural haematoma. The neuropsychiatrist will assess whether, for example, a depressive illness, anxiety disorder, psychosis or substance abuse explains the deterioration. But oftentimes there is no obvious explanation for the deterioration. This finding tallies with studies that find increasing cognitive impairment over time since injury in a proportion of patients.1 Explanations for this include accelerated cerebral atrophy2 and/or chronic inflammation3 or depleted cerebral reserve bringing forward age-related cognitive decline.4

Two papers with very different methodologies, one strong and one rather weaker, address the question of the long-term outcome after a head injury. Wang et al,5 interrogated a clinical database containing …