The medicolegal challenges of assessing psychiatric injury following a road traffic accident

As the number of cars on the road has increased, so has the likelihood of being involved in a road traffic accident (RTA). The nonfatal physical consequences of these incidents range from minor functional impairment to significant disability. However, there can also be an effect on psychological wellbeing. Both the physical and psychiatric sequelae of RTAs can be extremely detrimental to quality of life, both for the victim and their family.

The most frequent psychological disorders encountered after an RTA are acute stress disorder (ASD), post-traumatic stress disorder (PTSD), depression and anxiety. ASD and PTSD are characterised by dissociative symptoms, intrusion, avoidance and arousal. The main differences between the two conditions are the emphasis on dissociative symptoms in the diagnosis of ASD and the timing of symptoms. PTSD can only be diagnosed at least 4 weeks after the trauma, while ASD occurs from 2 days to 4 weeks after the incident. Depressive symptoms include persistent low mood, fatigue, sleep disturbance and a loss of interest in activities that the patient previously enjoyed. Anxiety can manifest as both psychological and physical symptoms, such as excessive worry, difficulty concentrating, irritability, sleep disturbance, increased heartbeat, sweating and muscle tension.

The pooled prevalence of ASD and PTSD after an RTA are around 16% and 23% respectively, although individual estimates vary widely due to assessment methods and numerous other factors. Depression occurs in 7.8% to 63% of RTA victims, while rates for anxiety disorder range from19.4% to 60%. Therefore, symptoms of psychological distress following an RTA are extremely common. Furthermore, a significant minority of patients report the presence of two or more of these conditions.

In general, rates of psychiatric symptoms decrease as time passes after the accident, but in a proportion of patients, they can persist for a considerable length of time. The presence of acute trauma responses soon after the accident strongly predict the long-term presence of mental health issues, as well as the progression to more serious psychiatric disorders, such as major depressive disorder and PTSD. Psychiatric status is also associated with an increased risk of disability. Furthermore, there is evidence that while patients may improve in terms of depression, symptoms indicative of PTSD may show a deterioration.

Psychiatric conditions are often accompanied by chronic pain. The relationship between the two is bi-directional, so that the presence of one increases the risk of the other and vice versa. If pain interferes with the patient’s physical and psychological functioning, it can subsequently lead to psychiatric issues and makes management of the patient more complex.  

Numerous factors can predict the likelihood of developing a psychiatric condition after an RTA. These include associated physical injuries; pre-existing cognitive bias and perceptions, such as catastrophic thinking; perceived threat to life; thinking about the trauma; levels of acute distress; pre-accident health-related quality of life; and social support networks. In addition, patients who are affected by multiple psychiatric disorders have an increased risk of at least one of these becoming chronic. Female gender has been reported to increase the likelihood of ASD and PTSD, which may be due to gender differences in coping strategies and the way that trauma is interpreted, or a reluctance in men to report negative post-traumatic responses.

Aspects of the accident itself may also affect the risk of psychiatric illness, which is predicted by fault in causing the accident and involvement in compensation or litigation. Patients who are not at fault in causing the RTA tend to show more emotional and psychological distress than those at fault. The relationship with compensation/litigation is less obvious, and it is unknown whether it results from the litigation itself, which may serve as a constant reminder of the trauma of the RTA, or factors associated with people who are likely to claim compensation. Motorcyclists also suffer higher levels of psychiatric illness than other road users, which may be linked to more disabling physical injuries and socioeconomic factors.

Evidence regarding the relationship between injury severity and psychiatric illness is contradictory, and it is also unclear whether it is the injury itself, or the trauma of the accident, that raises the risk of psychological distress. However, it seems likely that experiencing a traumatic accident could trigger a psychological reaction, even when no injuries are sustained.

The presence of mental health issues before the accident is an important consideration. Pre-existing conditions can make assessing current psychiatric status more challenging, as it is difficult to separate out previous symptoms from those specifically caused by the accident.

People who are involved in RTAs sustain high levels of psychiatric distress, which can persist for many years after the incident. Symptoms experienced in the weeks following the accident predict chronicity of psychiatric issues, demonstrating the need for early evaluation and intervention. Increasing the availability of psychological counselling at trauma centres and hospitals would substantially benefit RTA victims. Ideally, treatment should be offered for a period of up to 12 months, so that patients who show a delayed deterioration in their psychological state are not missed. Interventions should target early psychological reactions to trauma and cognitive thinking styles, whilst also addressing factors that influence resilience and recovery from adversity. This would optimise the chances of a full recovery after an RTA.