Depression

Despite new discoveries and development in depression medication, depression is still on the increase. The ones suffering from depression are thought to have altered levels of some of the chemical messengers in the brain, called neurotransmitters. The two principal chemical compounds involved are noradrenaline and serotonin. Nerve cells in the brain constantly produce, release and reabsorb the chemical serotonin. Lower levels of serotonin are thought to lead to the transmission of faulty messages and to be responsible for some of the symptoms of depression. Drugs such as selective serotonin reuptake inhibitors (SSRI) increase the levels of noradrenaline and serotonin. This increased brain activity is intended to improve mood. Once you've been diagnosed with depression, your doctor may prescribe a specific drug that meets your needs.

Types of Depression Medication
Antidepressants are mainly divided into three main classes:

• Tricyclic drugs (TCAs) i.e. Amitriptyline, Imipramine.
• Monoamine oxidase inhibitors (MAOIs). There are three types of MAOIs, phenelzine,(Nardil) isocarboxazid and tranylcypromine ( Parnate) and moclobemide.
• Selective serotonin reuptake inhibitors(SSRIs) are the most common prescribed today. They are sold under brand names such as Prozac, Paxil, Luvox, Zoloft, Celexa.

Newer "reuptake inhibitors" work on blocking the reuptake of different neurotransmitters (brain chemicals). Serotonin and norepinephrine reuptake inhibitors are becoming popular. (SNRIs)

In general SNRIs cause fewer side effects than TCAs and MAOIs.

Another type is Bupropion (Wellbutrin) - which is a dopamine reuptake blocking compound. It acts on the neurotransmitters dopamine and norepinephrine.

Interaction of Various Drugs

Tricylic Drugs
The tricyclics have been used to treat depression for a long time. They act on both serotonin and another neurotransmitter, norepinephrine, and may also interact with other chemicals throughout the body. They include amitriptyline (brand name: Elavil), desipramine (brand name: Norpramin), imipramine (brand name: Tofranil) and nortriptyline (brand names: Aventyl, Pamelor).

Tricyclic drugs are used in the treatment of:

• depression
• panic disorder
• obsessive-compulsive disorder
• post-traumatic stress disorder
• occasional chronic pain.

Side-effects. The side-effects caused by these medicines include dry mouth, blurred vision, constipation, difficulty urinating, worsening of glaucoma, impaired thinking and tiredness. These antidepressants can also affect a person's blood pressure and heart rate.

Other Antidepressants
The commonly used ones are venlafaxine, nefazadone, bupropion, mirtazapine and trazodone. Ther less commonly used are the monoamine oxidase inhibitors.These drugs are used in the treatment of several problems, namely:

• Depression
• Panic disorder
• Obsessive-compulsive disorder.
• Post-traumatic stress disorder.
• Occasional chronic pain.

Side effects. The side-effects in people taking venlafaxine (brand name: Effexor) include nausea and loss of appetite, anxiety and nervousness, headache, insomnia and tiredness. Dry mouth, constipation, weight loss, sexual problems, increased blood pressure, increased heart rate and increased cholesterol levels can also occur. Nefazodone (brand name: Serzone) can give people headaches, blurred vision, dizziness, nausea, constipation, dry mouth and tiredness. Bupropion (brand name: Wellbutrin) can cause agitation, insomnia, headache and nausea. MAOI antidepressants like phenelzine and tranylcypromine commonly cause weakness, dizziness, headaches and tremor.

SSRIs
SSRIs are the group of antidepressants that includes drugs such as escitalopram (brand name: Lexapro) citalopram (brand name: Celexa), fluoxetine (brand name: Prozac), paroxetine (brand name: Paxil) and sertraline (brand name: Zoloft). Selective serotonin reuptake inhibitors act only on the neurotransmitter serotonin, while tricyclic antidepressants and MAO inhibitors act on both serotonin and another neurotransmitter, norepinephrine, and may also interact with other chemicals throughout the body. These drugs are used in the treatment of:

• Depression
• Panic disorder
• Obsessive compulsive disorder
• Bulimia nervosa
• Social phobia

Side Effects
The common side effect that can be caused by SSRIs include dry mouth, nausea, nervousness, insomnia, headache and sexual problems. People taking fluoxetine might also have a feeling of being unable to sit still. People taking paroxetine might feel tired, have runny stools and diarrhea.