A depressive episode is often accompanied by signs such as constant low mood, a loss of interest in daily activities, and a loss of pleasure in things which the patient previously enjoyed. Many patients experience anger, which may cause issues at work or in close relationships. Cognitive difficulties, including poor concentration and poor memory, are also commonly reported. The likelihood of these may be increased by the sleep disturbances that are characteristic of depression. Depression is extremely common, occurring in around 6% of the population at any one time and around one in four people will experience at least one depressive episode during their lifetime.
Serious injury can be life-changing: it can lead to chronic pain, disability and psychological stress. If immediate or appropriate treatment is not received, this will increase the emotional impact. Furthermore, the inability to work, even in the short term, can result in financial hardship. All of these may lead to the patient developing depression. Therefore, a claim for compensation for depression often forms part of litigation for personal injury.
Depression is a recognised consequence of traumatic injury and high prevalence rates have been observed in patients who have experienced a traumatic event. For most patients, the symptoms of depression are mild, but moderate to severe symptoms are reported by up to 45% of patients and can sometimes last for years after the initial injury. Interestingly, depression scores tend to remain stable, whereas symptoms such as pain decrease over time. This suggests that depression is not directly caused by the injury and its consequences, but may also be due to pre-existing vulnerabilities, such as a tendency to process negative experiences differently.
The likelihood of developing depression is partly dependent on the seriousness of the injury. However, there is also some evidence that it is linked to the type of injury. Patients injured following a traffic accident are 1.72 times more likely to subsequently report depressive symptoms than the general population. However, in those with non-traffic-related injuries, the risk is more than doubled. Burn injuries and those sustained during interpersonal violence carry the highest risk, probably due to the increased trauma surrounding such events. Although many people gradually recover from the feelings of shock, denial, anger, sadness or guilt that are commonly associated with traumatic experiences and their consequences, in others these feelings persist and may over time develop into depression. Some people find it very hard to adapt to their new circumstances, particularly after suffering a life-changing injury such as an amputation.
Depression has been associated with reduced physical functioning and a decline in physical health over time. A worse quality of life, an increased risk of disability and a decreased likelihood of returning to work have all been linked to the condition, even when symptoms are relatively mild. It can also interact with symptoms such as pain, anxiety and post-traumatic stress disorder. These relationships appear to be bidirectional, with each heightening the effect of the others and giving rise to worse outcomes than for each symptom in isolation. Therefore, the interaction between mental and physical health may be useful in predicting the likelihood of disability. Chronic pain is a particularly important factor, as it is associated with many of the risk factors for depression, including sleep disturbances, poor quality diet, decreased physical activity and obesity.
There is no physical test to diagnose depression. Instead, it is identified by questioning a patient about how they are feeling and how this is impacting on their daily life, work and social relationships. Thoughts of suicide or self-harm are particularly indicative of depression. As the onset of the condition is often gradual, it can sometimes be difficult to notice changes in mood, behaviour or physical symptoms until these are very severe. Often it is a family member or friend who first suspects there is a problem. Not surprisingly, many cases remain undiagnosed.
Depression is frequently a recurrent illness, so many patients will have had previous episodes. Furthermore, it is not always caused by a single identifiable event. It is a complex condition, and many factors can contribute to its development. This can complicate personal injury claims that include depression, as it can be difficult to determine if the patient would have developed the depressive episode even in the absence of the index injury. Even in patients with a prolonged history of depression, it could be argued that the trauma suffered when they were injured has exacerbated their condition, and proving or disproving this is challenging.
The picture is complicated further by the relationship between depression and injury. It is now known that pre-existing depression can be a risk factor for accidents and injuries. In particular, the sleep disruption associated with depression has been shown to increase the risk of road traffic accidents and occupational injuries. This is likely due to the inattention, decrease in vigilance and slowed reaction times caused by insomnia, particularly if it is chronic. Pre-existing depression is twice as likely to be reported in individuals taking time off work due to injury or non-mental health related illness compared to colleagues who remain at work. Therefore, determining the level of compensation due in personal injury claims where depression is also cited is extremely difficult.
Further reading:
Gaspar FW, Jolivet DN, Wizner K, Schott F, Dewa CS. Pre-existing and new-onset depression and anxiety among workers with injury or illness work leaves. J Occup Environ Med. 2020 Oct;62(10):e567-e572.