Antidepressant drug therapy has been shown to increase quality of life in depressed older adults. These medications must be carefully monitored for side effects, and when prescribed for older adults, doses are usually lower and increased more slowly than in younger adults. This is because more side effects are often reported (eg. increased falls) and more drug interactions are seen in older adults.
Antidepressants work by changing the level of neurotransmitters (chemical messengers) in the brain. Several neurotransmitters are thought to be in low supply in depression, including noradrenaline (sometimes called norepinephrine) and serotonin. Tricyclics mainly increase the level of noradrenaline in the brain. The SSRIs work by increasing the supply of serotonin only. The SNRIs and RIMAs increase the supply of both serotonin and noradrenaline in the brain.
The treatment for major depression in older adults is the same as for younger patients. This most commonly prescribed first line treatments include selective serotonin reuptake inhibitors (SSRI's) and similar agents like serotonin and norepinephrine reuptake inhibitors (SNRI’s) and tetracyclic antidepressants.
Tricyclic antidepressants (TCA's), monoamine oxidase inhibitors (MAOIs) (not used commonly now), and ECT may be used if responses to other lines of therapy are limited.
Older people may require smaller doses to achieve therapeutic levels because of decreased metabolism and clearance. It is important to consider drug interactions if the person is taking numerous medications.
Most antidepressants are equally effective. But some pose a higher risk of serious side effects. See below for more details...