Types of Antidepressants

Antidepressants are of three main types

1. Monoamine oxidase inhibitors - MAOIs
2. Selective serotonin reuptake inhibitors - SSRIs
3. Tricyclics - TCAs

The newest antidepressants tend to be SSRIs, or selective serotonin reuptake inhibitors as the name itself suggest that they work selectively and primarily on a tipical neurotransmitter in the brain serotonin. SSRIs are well known about its least side effects. The side effects of SSRIs are nothing but just annoying, though the side effects can be any of the headaches or agitation or it may be related to sexual problems. The popular antidepressants of the SSRI type are Prozac, Luvox and Paxil.

The tricyclic antidepressants are not used for neurotransmitter, but they are chemical composition. These are mainly used for treatment of major depression from many years. Tricyclics' side affects many types overlaps with SSRIs' side effects to a certain extent like sexual dysfunction. They also increase the drowsiness with alcohol. Tricyclic antidepressants may also cause blurred vision, dry mouth as well as intestinal problems. The more used tricyclic antidepressants are Elavil, Anafranil, Norpramin and Vivactil.

Monoamineoxidase inhibitors or MAOIs, are the most older antidepressants. The MAOIs were first antidepressant developed and neurotransmitters responsible for mood, primarily norepinephrine and serotonin, are also known as monoamines. Monoamine oxidase is an enzyme, which breaks these substances down. Monoamine oxidase inhibitors, as the name implies, inhibits this enzyme, thus allowing a greater supply of these chemicals to remain available. They are not so often used as the tricyclics or SSRIs, but they often used for those with the depression that cannot be curable by other medications. Like the SSRIs, MAOI antidepressants are named such because their functionality is to block the brain monoamineoxidase. Those who take this should avoid food like cheese and alcohol, as well as certain medications. The generally used MAOI antidepressants are Nardil and Parnate.

Doctor when prescribe any of the antidepressants they should be totally educated to decide severity of the patient's depression. All of the side effects of these antidepressants should be considered and explained to the person who is going to take it.

Antidepressant Classes

The main and the basic classes are three and known chemically as monoamines, which are thought to play a role in mood regulation:

1. Norepinephrine
2. Serotonin
3. Dopamine

Antidepressant are actually categorized by the side effect of the chemicals they contain. The following are the major antidepressants classes:

• Monoamine Oxidase Inhibitors
• Tricyclics
• Selective Serotonin Reuptake Inhibitors

Newer Mechanisms

Below are the five newer antidepressants which do not fit into the above categories are as listed:

1. buproprion (Wellbutrin)
2. nefazodone (Serzone)
3. trazodone (Desyrel)
4. venlafaxine (Effexor)
5. mirtazapine (Remeron)

The mechanism of bupropion antidepressant is the poorly understood, can be mediated through noradrenergic or dopaminergic pathways or both. Nefazodone and its precursor trazodone both of them inhibit neuronal reuptake of serotonin and, norepinepherine. Venlafaxine is a compound that is unrelated to other antidepressants. Like the TCAs, venlafaxine inhibits the neuronal uptake of both serotonin and norepinepherine.

Mirtazapine has unique mechanism of action and it not at all involves enzyme inhibition or blockade of neurotransmitter reuptake. It also increases the release of norepinepherine from central noradrenergic neurons by blocking the presynaptic inhibitory alpha-2 autoreceptors. It spares alpha-1 postsynaptic receptor and therefore results in net increase noradrenergic transmission.

Resources for Fighting Depression:

• Self Help for Depression
• End Depression Now
• Conquer Stress, Depression & Anxiety