Depression, though common, is a serious illness which affects a person's ability to function in a normal manner. The National Institute of Mental Health states that a chemical imbalance may be a contributing factor, although the medical community has yet to identify one particular cause. Antidepressants help restore this balance, thus relieving the symptoms of depression. A variety of antidepressants are available to treat depression, and are categorized according to the chemicals they affect.
Paroxetine (Paxil)
Paroxetine belongs to the family of antidepressants known as SSRIs, or selective serotonin reuptake inhibitors. It helps treat the symptoms of depression by restoring the balance of serotonin in the brain. According to the Drugs website, it may take up to four weeks before a person notices an improvement in symptoms. Some of the most common side effects associated with paroxetine include drowsiness, mild nausea, decreased sex drive, insomnia, dizziness, constipation and dry mouth.
Venlafaxine (Effexor)
Venlafaxine is a member of the SNRI family, better known as serotonin-norepinephrine reuptake inhibitors. This is a fairly new drug family in the world of antidepressants, according to Healthy Place, and helps balance both serotonin and norepinephrine. Venlafaxine is one of three drugs in this family, and is available in three forms--a tablet, an extended-release tablet and an extended-release capsule. This medication may take four weeks to work as well, and some of its most common side effects include headache, blurred vision and high blood pressure.
Imipramine (Tofranil)
Imipramine is a tricyclic; tricyclics were the first antidepressants available for the treatment of depression, and imipramine was the first tricyclic produced. It was released in 1958 as Tofranil, however because the newer antidepressants such as the SSRIs and SNRIs have fewer side effects, the tricyclics are typically prescribed either when no other medication has worked, or is used in cases of major depression. Some of its most common side effects are breast enlargement in females or the development of breasts in men, confusion, dry mouth, diarrhea, nausea and hallucinations.
Phenelzine (Nardil)
Phenelzine is a member of the MAOI family--monoamine oxidase inhibitors. MAOIs were created shortly after tricyclics and affected not only serotonin and norepinephrine, but also dopamine. According to the PDR Health site, phenelzine needs to be taken three times a day, usually in doses of 15 mg; this, however, is at the discretion of a physician. While side effects cannot be predicted, those most commonly associated with this drug include dizziness, drowsiness, muscle twitching, decreased sex drive, weight gain, insomnia and blurred vision.
