Antidepressants and Weight Gain

Antidepressants are medications prescribed for the treatment of depression, psychotropic and seizure disorders. It is generally believed that people with depression have an imbalance in the brain's neurotransmitters.

Neurotransmitters are chemicals in the brain that allow nerve cells to communicate. Most antidepressants work by slowing the removal of certain chemicals from the brain and making these natural chemicals more available to the brain. They are usually taken for a period of 4 to 6 months. You will need a doctor’s prescription to buy these medications and they should be strictly taken under a doctor’s guidance. 

A common side effect of these medications is weight gain. The higher the dosage of medication, the more likely weight gain will be an issue. Antidepressants can affect weight in several ways:

• They may decrease the body’s metabolism which could lead to weight gain.

• They may affect hormonal changes by blocking the histamine receptors and increasing the appetite.

• Patients on these medications typically have an uncontrollable urge to eat starchy or sweet foods

It has been proven that Paxil, Zoloft, Remeron and Luvox appear to cause the most weight gain, with Prozac and Welbutrin sometimes causing weight decrease. However, many people still gain weight with any of the classes of antidepressant drugs.

Kinds of antidepressants:
Antidepressants are categorized based on the chemicals in the brain they affect. There are many different kinds of antidepressants including:

• Selective serotonin reuptake inhibitors (SSRIs): These medications work by optimizing the utilization of serotonin in the brain. They are named selective inhibitors because they only affect one chemical without disturbing the equation of the others. Serotonin inhibitors appear to have fewer side effects than other antidepressants. Some of the side effects include dry mouth, nausea, nervousness, insomnia, sexual problems and headache. Some examples of SSRIs are:

• citalopram (brand name: Celexa)

• escitalopram (brand name: Lexapro)

• fluoxetine (brand name: Prozac)

• paroxetine (brand names: Paxil, Pexeva)

• sertraline (brand name: Zoloft)

• Tricyclic anti depressants (TCAs): There are three rings of atoms in the drugs molecular structure and the name tricyclic comes from that. It is believed they work by inhibiting the re-uptake of the neurotransmitters in the brain. Common side effects include dry mouth, blurred vision, constipation, difficulty in urinating, glaucoma, impaired thinking and tiredness. Some examples of TCAs:

• amitriptyline (brand name: Elavil)

• desipramine (brand name: Norpramin)

• imipramine (brand name: Tofranil)

• nortriptyline (brand name: Aventyl, Pamelor)

• Combined reuptake inhibitors and receptor blockers: These are dual-action antidepressants that act on brain cells both by inhibiting the reabsorption of neurotransmitters into nerve cells and by blocking nerve cell receptors. Common side effects include drowsiness, dry mouth, nausea and dizziness. Some examples:

• trazodone (brand name: Desyrel)

• nefazodone (brand name: Serzone)

• mirtazpine (brand name: Remeron).

• Monamine oxidase inhibitors (MAOIs): They are one of the oldest classes of antidepressants and are usually used as a last resort. They cause dangerous interactions with certain foods and medications. They can have serious side effects including weakness, dizziness, headaches and tremors. Some examples:

• isocarboxazid (brand name: Marplan)

• phenelzine (brand name: Nardil)

• ranlcypromine (brand name: Parnate)

Some ways of coping with medication induced weight gain include trying lowers doses of the medication or switching to another type of medication. Proper diet and exercise are also essential in such cases. Always remember to consult your health care provider if you have any concerns regarding the medication you are taking and gaining weight.