Antidepressants
are the drugs used by psychiatrists for treating patients suffering
from symptoms such as low mood, lack of self esteem, lack of interest,
lethargy, excessive sadness, self regret, feeling of worthlessness…etc,
which are collectively known as ‘depressive symptoms’. There are several
antidepressants that have been used to treat these symptoms and
although it may not bring about a lasting cure, in most instances it can
manage the symptoms giving relief to the patient until they are able to
cope with such symptoms on their own.
Commonly used antidepressants
Among the most common antidepressants that are being used, selective serotonin reuptake inhibitors (SSRI) and Tricyclic Antidepressants (TCA)
are rather common with another category of drugs known as ‘MAO
inhibitors’ or monoamine oxidase inhibitors. In order to understand how
these antidepressants work, it is necessary to understand ‘what is the
basis of depression’ among patients who are having symptomatic
depressive illness.
The biochemical basis of depression
According
to scientists, the reason for clinical depression could largely be due
to the diminished levels of neurotransmitters (e.g serotonin and
norephinephrin) within the ‘synaptic junctions’ existing between two
neurons in the human brain. The neurons are the ones which transmit
signals and the neurotransmitters are the chemical substance which
carries a message from one neuron to the next. The transmitters are
usually located at the end portion of the neuron known as the ‘synapse’.
In response to a transmissible signal such as feeling of hunger,
happiness, excitement…etc, the transmitters are released into the
synaptic junction. It could them stimulate the receptors at the
beginning of the next neuron which initiate a signal propagation.
Following stimulating the receiving neuron, the neurotransmitters will
again be re-absorbed into their original location in a process known as a
‘re-uptake’. As a result, these transmitters will be able to perform
the same function over and over again.
In patients with depression, there seems to be an inherent deficiency of these neurotransmitters and therefore the signals may not be propagated effectively.
In patients with depression, there seems to be an inherent deficiency of these neurotransmitters and therefore the signals may not be propagated effectively.
The basis of antidepressant actions
Thus,
the actions of antidepressants would either be to increase the
existence of adequate amount of neurotransmitters within the synaptic
junction or else to prevent its natural destruction through a substance
known as ‘monoamine oxidase’.
Specific actions of antidepressants
Thus,
both SSRIs and TCAs will inhibit the re-uptake process and will make
available more neurotransmitters within the synaptic junction. However,
the MAO inhibitors will act in a different manner and will inhibit the
action of Monoamine oxidase thus preventing the breakdown of the
neurotransmitters thereby increasing its availability for normal signal
transmission.
Although this is a simplified explanation of how antidepressants are functioning, it captures the most important aspect necessary in explaining the phenomenon.
Source: http://pandula77.hubpages.com/hub/How-antidepressants-work-Pharmacology-of-anti-depressants
Although this is a simplified explanation of how antidepressants are functioning, it captures the most important aspect necessary in explaining the phenomenon.
Source: http://pandula77.hubpages.com/hub/How-antidepressants-work-Pharmacology-of-anti-depressants
