Depression is a common mental health condition characterised by persistent low mood, loss of interest or pleasure in activities (anhedonia), and a range of physical and psychological symptoms. These can include fatigue, changes in sleep and appetite, difficulty concentrating, feelings of worthlessness or guilt, and in severe cases, thoughts of self-harm or suicide. Depression is distinct from normal sadness: it is more intense, longer lasting (typically two weeks or more), and affects the ability to function in daily life.
Depression is significantly more common after cardiac arrest than in the general population, with studies suggesting that 25 to 40 per cent of survivors experience clinically significant depressive symptoms in the months following the event. This is partly a psychological response to the trauma and life disruption of cardiac arrest, and partly related to the neurological effects of hypoxic brain injury. The relationship between depression and cardiac disease is bidirectional: depression increases the risk of cardiac events, and cardiac events increase the risk of depression. Untreated depression after cardiac arrest is associated with poorer rehabilitation engagement, worse quality of life, and increased mortality.
Depression frequently co-occurs with post-traumatic stress disorder (PTSD) and health anxiety in cardiac arrest survivors, and the conditions can overlap. The first step is usually a conversation with a GP, who can use a validated screening tool (such as the PHQ-9) to assess severity and guide treatment.
NICE recommends several evidence-based treatments for depression: cognitive behavioural therapy (CBT) for mild to moderate depression, antidepressant medication (most commonly SSRIs), and a combination of both for moderate to severe depression. Acceptance and Commitment Therapy can also be helpful for people adjusting to chronic health conditions. NHS Talking Therapies services offer self-referral for CBT and other psychological therapies without needing a GP referral first. Cardiac arrest survivors with depression should be transparent with their cardiologist, as some antidepressants can have cardiac effects and the choice of medication should take this into account.