Suicide is associated with traumatic brain injury according to the study described by Teasdale and Engberg in this volume (pp436–440).1 Using the opportunity for record linkage in Denmark, the authors compared suicide rates after concussion, cranial fracture, and probable brain lesion (defined as those with International Classification of Diseases codes for cerebral contusion or traumatic intracranial haemorrhage). All these groups, as expected, had higher suicide rates than the general population. Of most interest though is that those with lesion had higher suicide rates than those with concussion (hazard ratio 1.4; 95% confidence interval (95%CI) 1.2–1.8) and fracture (1.5; 95% CI 1.1–2.1) after adjustment for sex, age at injury, and substance misuse.

The reliance on routine data will raise concerns about the quality of the original head injury classification. However, any random misclassification would be expected to have reduced the size of association. The strength of the study is in the comparison within the group who have received head injuries. On balance this seems to be an interesting and robust finding that deserves replication.

Suicide is an important cause of premature mortality, especially in young men. An increase in suicide rate of the size described by Teasdale and Engberg1 will have an important impact on the health and life expectancy of those with cerebral lesion after head injury. What is the likely cause of this increase and what action should clinicians take in response to the finding?

Two possible risk factors for suicidal behaviour seem relevant. Firstly, psychiatric disorder, especially depression, is associated with suicidal behaviour.2 There is evidence that there are high rates of psychiatric morbidity and neurobehavioural problems in those with head injury.3 Secondly, there are higher rates of suicide in those reporting chronic illness and unemployment.4 Feelings of hopelessness together with a poor quality of life can contribute towards suicidal behaviour.

These findings argue strongly for the importance of identifying and effectively treating depression and anxiety in people with head injury. This is no simple matter as patients are often reluctant to divulge psychological symptoms or see them as normal reactions to difficult circumstances. Linked to this is the role of rehabilitation services in providing an active, structured programme of social and occupational interventions to reduce disability.

Patients with head injury often fall into a gap between services for elderly people with stroke and younger people with psychiatric problems. All too often, patients with head injury do not receive services that can be tailored to their particular needs. An increased rate of suicide is possibly one of the most tragic and most traumatic consequences of head injury. Services for people with head injury can be improved and this should help to make their life worth living.