Antidepressants are broadly classified according to their mode of action on neuro -transmitters in the brain. Neuro-transmitters are natural chemical substances, manufactured by nerve-cells (neurons) within the brain. They carry electrical messages across gaps (synapses), which exist in abundance between neurons. These chemical transmitters may be over or underactive in mood disorders such as depression and mania.
There is also evidence which suggests that receptors - i.e. specialized proteins on nerve cell endings which are particularly sensitive to different transmitters - may become under or over sensitive to neuro-transmitters in these disorders - producing the same result as caused by too little or too much neurotransmitter.
Antidepressant drugs all appear to work by altering the amount of available transmitter up or down, or by altering the sensitivity of receptors either up or down - or by a combination of both mechanisms.
This is a much over-simplified description of the state of current research but is nevertheless an important starting preliminary concept to grasp.
Antidepressant drugs are usually classified depending on their mechanism of action: that is, how they are believed work. Some drugs seem to be limited in their actions to one neurotransmitter (selective anti-depressants) while others may influence two or more neuro-transmitters. The latter are sometimes called broad-spectrum anti-depressants.
The first discovered group of antidepressants, the tricyclic antidepressants (TCAs), are considered broad-spectrum because they influence the activity of many different neurotransmitters. However, because of this wide-ranging activity they tend to have more side effects. Nevertheless they are powerful and generally reliable as antidepressants.
Antidepressants are broadly classified according to their mode of action on neuro -transmitters in the brain. Neuro-transmitters are natural chemical substances, manufactured by nerve-cells (neurons) within the brain. They carry electrical messages across gaps (synapses), which exist in abundance between neurons. These chemical transmitters may be over or underactive in mood disorders such as depression and mania.
There is also evidence which suggests that receptors - i.e. specialized proteins on nerve cell endings which are particularly sensitive to different transmitters - may become under or over sensitive to neuro-transmitters in these disorders - producing the same result as caused by too little or too much neurotransmitter.
Antidepressant drugs all appear to work by altering the amount of available transmitter up or down, or by altering the sensitivity of receptors either up or down - or by a combination of both mechanisms.
This is a much over-simplified description of the state of current research but is nevertheless an important starting preliminary concept to grasp.
Antidepressant drugs are usually classified depending on their mechanism of action: that is, how they are believed work. Some drugs seem to be limited in their actions to one neurotransmitter (selective anti-depressants) while others may influence two or more neuro-transmitters. The latter are sometimes called broad-spectrum anti-depressants.
The first discovered group of antidepressants, the tricyclic antidepressants (TCAs), are considered broad-spectrum because they influence the activity of many different neurotransmitters. However, because of this wide-ranging activity they tend to have more side effects. Nevertheless they are powerful and generally reliable as antidepressants.
