Revise Treatment and management of mood (affective) disorders for Cambridge 9990 (1.2.3)

Antidepressants are the most common biological treatment for depression, based on the monoamine hypothesis which suggests the disorder is caused by low levels of neurotransmitters like serotonin. The most widely prescribed class is Selective Serotonin Reuptake Inhibitors (SSRIs), such as fluoxetine. SSRIs work by blocking the reuptake pump on the presynaptic neuron, increasing the amount of serotonin available in the synaptic cleft to stimulate the postsynaptic neuron. This is thought to alleviate depressive symptoms over several weeks. While studies like Cipriani et al.'s (2018) meta-analysis show they are effective, they are not a universal cure. Side effects, including nausea and insomnia, can affect adherence, and stopping medication can lead to relapse if underlying psychological factors are not addressed.

Cognitive Behavioural Therapy (CBT) is a leading psychological treatment for depression. It operates on the principle that our thoughts, feelings, and behaviours are interconnected. The therapy aims to help individuals identify and challenge the negative automatic thoughts characteristic of depression, such as those in Beck's negative cognitive triad (negative views of self, world, and future). This process is known as cognitive restructuring. The behavioural component, 'behavioural activation', encourages clients to schedule and engage in rewarding activities to counteract anhedonia and social withdrawal. As a structured, time-limited therapy, CBT equips patients with lasting coping skills, making it highly effective for preventing relapse, as supported by numerous studies like the meta-analysis by Butler et al. (2006).

Electroconvulsive Therapy (ECT) is a specialised treatment reserved for cases of severe, treatment-resistant depression, or when a rapid response is critical due to high suicide risk or catatonia. The modern procedure is performed under general anaesthetic and with a muscle relaxant to prevent injury. A precisely controlled electric current is passed through the brain, inducing a brief, therapeutic seizure lasting about 30-60 seconds. While the exact mechanism is not fully understood, it is thought to cause widespread changes in brain chemistry and connectivity, effectively 'rebooting' certain neural circuits. Despite its high efficacy for severe depression, ECT remains controversial due to its invasive nature and potential side effects, most notably temporary confusion and both anterograde and retrograde memory loss.

An interactionist approach, combining biological and psychological treatments, is often considered the gold standard for moderate to severe depression. Typically, this involves prescribing antidepressants alongside a course of CBT. The rationale is synergistic: medication can provide relatively rapid relief from debilitating symptoms like low energy and poor concentration, making the patient more able to engage with the demanding cognitive work required in CBT. In turn, CBT provides long-term strategies for managing thoughts and behaviours, which helps to reduce the risk of relapse after the medication is eventually discontinued. Major studies, such as the Treatment for Adolescents with Depression Study (TADS, 2004), have demonstrated that this combined approach is more effective than either treatment used in isolation.