The relationship between traumatic brain injury and neuropsychiatric conditions has a strong clinical link. Despite significant clinical presentations, there has been a limited focus on quantifying the association between traumatic brain injury and psychiatric disorders.

To conduct a systematic review to determine the prevalence and incidence of neuropsychiatric conditions in patients with traumatic brain injury.

To determine the association between traumatic brain injury and psychiatric illness.

A systematic search was made of Medline, PsycINFO, EMBASE and article bibliographies. Search terms for rates of psychosis, mood disorders, anxiety conditions, organic personality disorder, neuropsychiatric disorders, neuro-behavioural disorders, aggression, dementia and frontal lobe disorder were utilised. We followed MOOSE criteria and did not apply temporal limits.

There were 845 relevant searches in total. After exclusion of duplicates, case reports, case series reports, letters, reviews, commentaries, systematic reviews, and editorials there were 143 relevant abstracts identified. This was further reduced to a review of 48 full text papers. We identified prevalence rates of depression between 6.9–62.5%, mania of 9–12.5%, PTSD 1.9–50%, aggression 28.4–57%, anxiety disorders 6–63% (including GAD 8–9%, agoraphobia 2–6%, panic disorder 9%, social phobia 1%) insomnia 11–29%, personality change of 33.3%, dementia 8.16% and substance use 3–8%.

We have identified significant rates of neuropsychiatric morbidity in patients with traumatic brain injury. We have particularly identified limited research studies into psychosis, mania, dementia and personality disorders in this patient group. The review further emphasises the importance of identifying neuropsychiatric comorbidities in post-traumatic brain injury and the importance of addressing these comorbidities.

The authors have not supplied their declaration of competing interest.