Chemotherapy - antidepressant drugs
Antidepressans are drugs that relieve the symptoms of depression. There are several different types, although will will only focus on the older 'tricyclic' antidepressants and the newer 'SSRIs' (selective serotonin reuptake inhibitors) here. These drugs are used to reate moderae to severe depressive illnesses. Anitdepressants are typically taken for at least four to six months, although in some cases they are needed for a longer time.
How do they work? Depression is thougt to be due to insufficient amoun of neurotransmitters such as noradrenaline and serotonin being produced in the neuron endings to activae their neighbouring cells. In normal brains neurotransmitters are constantly being released at synapses, stimulating the neighbouring cells. To terminate their action, neurotransmitters are re-absorbed into the never endings or are broken down by an enzyme which breaks down the neurotransmitters. Both of these emthods increase the amount of neurotrasmitters available to excrite neighbouring neurons.
Tricyclics block the transporter mechanism that re-absorbs both serotonin and noradrenaline into the presynaptic cell after it has fired. As a result, more of these neurotransmitters are left in the synapse, prelonging their activity, and making transmission of the next impulse easier.
Selective serotonin re-uptake inhibitors (SSRIs) work in much the same way as the tricyclics but, instead of blocking the re-uptake of different neuroransmitters, they block mainly serotonin and so increase he quantity available to excite neighbouring brain cells, thus reducing the symptoms of depression. The best known of these drugs is Prozac (fluoxetine).
Phases of treatment The treatment of depression has three distinct phases. The treatment of current symptoms takes place during the acute phase of reatment. Once symptoms have diminished, reatment eneters the continuation phase for approximately four to six months, after which medication is gradually withdrawn in order to prevent a relapse. A third phase, maintenance, is recommended for individuals who have a history of recurrent depressive episodes.
Electroconvulsive therapy (ECT) is generally used in severely depressed patients for whom psychtherapy and medication have proved ineffective. It is used when there is a risk of suicide because ECT often has much quicker results than antidepressant drugs. NICE (2003) suggets that ECT should only be used in cases where all other treatemtns have failed or when the condition is considered to be potentially life-threatening.
What happens in ECT? Exactly how and why ECT works is not completely understood, but what is clear is tha it is the seizure rather than the electrical stimulus that generates improvement in depressive symptoms. The seizure appears to restore the brain's ability to regulate mood. It may do this by enhancing the transmission of neurotransmitters or by improving blood flow in the brain.
Cognitive-behavioural therap (CBT) emphasises the role of maladaptive thougts and beliefs in the orgins and maintance of depression. When people think negatively about themselves and their life, they become depressed. The aim of CBT is to identify and alter these maladaptive cognitions (the cognitive…