Comorbidity of mental disorders and substance use: a brief guide for the primary care clinician
12.4 Does brain injury predispose individuals to mental disorders or to suicide?
12.4.1 Brain injury and mental disorders
- Emotional and psychiatric disturbances are common following brain injury, with those who have a past history of brain injury being diagnosed with a significantly greater number of psychiatric disorders. This association seems to apply to those within the general population who have been identified as having had a head injury, as well as specific patient populations attending brain injury rehabilitation services(503, 506, 510, 511).
- There is controversy as to whether pre-brain injury psychiatric morbidity is predictive of postpsychiatric morbidity(503, 504, 506, 511, 512). Some authors have postulated that individuals with no prebrain-injury psychiatric history may actually be more likely to develop post-brain injury psychiatric morbidity as they are likely to experience greater lifestyle changes(504).
- The most frequently reported psychological challenge following brain injury is depression, with increased rates observed in individuals with a history of brain injury(503-505, 507, 512-516).
- Occurrence of depression appears to be unrelated to severity of brain injury(504, 505, 512, 514, 516, 517).
- Emotional disturbances following brain injury are disruptive both socially and occupationally and greatly affect daily functioning. Individuals who experience brain injury and depression have been observed to have generally poorer health outcomes (both physically and emotionally). They report higher levels of psychosocial dysfunction, psychological distress, neurobehavioural and cognitive dysfunction, including memory problems, and also have diminished life satisfaction(503, 506, 512, 516-518).
- There is significant debate as to whether depression following brain injury is an episodic event and perhaps a normal phase in the overall initial adjustment to brain injury, or whether depression following brain injury is a long-term disorder. There appears to be a lack of correlation between the time after injury and the onset of depression. It is suggested that depression may occur at any time following brain injury with no clearly defined time line for resolution(504, 505, 512-516).
- Resolution of depression following brain injury is accompanied by improvement in psychosocial functioning and perceived enhancement of one's health(512).
- Increased rates of anxiety following brain injury have also been observed, most commonly in people with PTSD, panic and OCD (e.g. writing and checking lists to compensate for cognitive disabilities)(503-506, 514).
- Anxiety disorders are more likely to present as comorbidity with other Axis 1 diagnoses(503, 504, 512).
- Comorbidity with mental disorders following brain injury is common, with more than one psychiatric disorder being identifiable in many individuals(503, 504, 512, 514).
- The incidence of psychiatric disorders such as bipolar disorder and schizophrenia following brain injury more closely resembles that of the general population and is much less prevalent than depression and anxiety following brain injury(503, 504, 506, 514).
Implications for management
- Considering that mental disorders are common following brain injury, post-brain injury management should routinely include a psychological assessment.
- Assessments should be undertaken at regular intervals following brain injury. It is important to try to establish what the mental health of the patient was prior to the injury and, particularly, to assess for the presence of anxiety and depression on an ongoing basis after the injury(504, 512, 514-516).
- People who have experienced brain injury, as well as their families, should be made aware of the risk of experiencing a mental disorder in the future. This should be done whether or not the patient had mental health problems prior to the injury(504)
- Individuals may present with hidden brain injury where the patient does not associate a connection between current problems and a previous brain injury. Brain injury-related symptoms such as problems with memory, attention, fatigue, the processing of multiple stimuli and impulse control may not be managed appropriately(506). Therefore, the possibility of brain injury in people presenting with non-specific cognitive type problems should be considered by the clinician.
- Early identification and treatment of depression following a brain injury may directly improve outcome and quality of life. Considering the effects of depression on cognitive impairment in those with brain injury(512, 516, 517), detection and appropriate management of depression may allow cognitive therapy approaches for brain injury to be more effective.
- A number of motor, sensory and cognitive deficits overlap with the vegetative features of depression and may lead to over-diagnosis of depression. Similarly, there is significant symptom overlap with post-concussive syndrome(505). Feelings of hopelessness, worthlessness and anhedonia which are more specific features of depression that should be looked for by the clinician(516, 519).
12.4.2 Brain injury and suicide
- People who have experienced traumatic brain injury have been shown to have increased rates of suicidal ideation, suicide attempts and completed suicide. This increased risk has been attributed to both the presence of a mental disorder and to the problems associated with adjustment to living with a brain injury(501, 505, 506, 510).
- Individuals with brain injury employ a wide range of diverse methods to commit suicide(520).
- Suicide following brain injury may be the result of multiple factors: the suddenness of onset of disability in previously healthy individuals, the global effects of disability, grief over the loss of a pre-injury lifestyle, the growing realisation of the effort involved in maintaining a similar level of functioning to that prior to brain injury, as well as a reduced level of neuropsychological coping mechanisms(510, 520).
- Emotional and psychiatric disturbances and suicide ideation following brain injury have been shown to be significant predictors of suicide attempts(510).
- Thoughts of hopelessness may be a stronger predictor of suicide ideation than the presence of depression alone(505, 510).
- There is uncertainty about whether suicidal ideation is related to the severity of brain injury per se or whether it is related to the person's assessment of the effects of the injury.
- Pre-injury history of suicide attempts does not seem to confer additional increased risk post-injury(501, 510).
- In parallel with the observations of the timing of depression following brain injury, the risk of suicide does not diminish but may fluctuate over time following brain injury(501, 505, 510). Years of disappointment can set in and the individual may have to face the confronting fact that they will not return to full premorbid functioning(501).
Implications for management
- The main clinical concern is the prevention of suicide(520).
- There are increased numbers of individuals accessing GP services following brain injury; therefore, the GP is in an ideal position to monitor the patient’s mental state and suicide risk(519).
- Individuals with brain injury may present for medical reasons and may not reveal suicidal ideation(519).
- Assessment needs to involve seeking a history of pre-brain injury:
- Suicidal behaviour.
- Substance use.
- Psychological disorders.
- Assessment needs to include a history of post-brain injury suicide attempts as these are far more predictive of suicide risk following brain injury.
- Post-brain injury management needs to include continuous and extended monitoring of warning signs for risk of suicide, including:
- Symptoms of hopelessness and suicidal ideation(510, 519).
- Signs that the individual is not adjusting to life following brain injury.
- To prevent isolation, there is a need to continuously monitor the individual’s support networks, including social and familial. There is also a need to provide education to individual and support networks in relation to difficulties that may be encountered following brain injury(519, 520).
- As individuals with brain injury may attempt suicide using a range of methods. It is important to reduce lethality where possible by:
- Identifying the safest approach for prescribing, dispensing and administering medications(519).
- Ensuring that people at risk have minimal access to weapons such as firearms(519).