How they work: They change the levels of neurotransmitters, namely, dopamine, acetylcholine, serotonin, and adrenaline in the brain.

Side effects: Headache, drowsiness, dizziness, disturbed sleep, nausea, nervousness, excitement, and allergic reactions in some people (seen as hives, rashes, swelling over the face, and difficulty breathing).

Examples: Buspar or Vanspar ( buspirone).

How they work: The exact mechanism of action is not known, but it is thought to modulate serotonin levels in the brain.

Side effects: Dry mouth, constipation, weight gain, blurred vision, rash, hives, increased heart rate, and postural hypotension (fall in blood pressure on standing).

Examples: Tofranil ( imipramine), Elavil ( amitriptyline), and Sinequan ( doxepin).

They do this by increasing the levels of serotonin and norepinephrine while reducing the levels of another neurotransmitter called acetylcholine.

How they work: These medications act by restoring the balance of certain neurotransmitters in the brain.

Side effects: Headache, disturbed sleep, drowsiness, nausea, vomiting, diarrhea, blurred vision, nervousness, restlessness, agitation, and sexual dysfunction.

Examples: Lexapro ( escitalopram), Prozac ( fluoxetine), and Celexa ( citalopram).

Increased serotonin levels improve mood and help relieve anxiety.

How they work: They increase the brain levels of serotonin by blocking its reuptake by the nerve cells.

Selective serotonin reuptake inhibitors.

Side effects: Constipation, dry mouth, dizziness, headache, hot flushes, nausea, diarrhea, reduced libido, and erectile dysfunction.

Examples: Pristiq ( desvenlafaxine), Cymbalta ( duloxetine), and Effexor ( venlafaxine).

SNRIs act by blocking or reducing the reuptake of these two hormones by the nerve cells, thus increasing their activity in the brain. These hormones are types of feel-good hormones that improve mood.

How they work: They increase the brain levels of the two hormones called serotonin and norepinephrine.

Serotonin-norepinephrine reuptake inhibitors (SNRIs) (also called selective serotonin-norepinephrine reuptake inhibitors or SSNRIs).

Side effects: Fatigue, weight gain, cold hands or feet, trouble breathing, difficulty sleeping, and disturbed blood lipid levels may trigger asthma in susceptible individuals.

Examples: Inderal ( propranolol), Sectral ( acebutolol), and Zabeta ( bisoprolol).

Consequently, the symptoms such as a racing heartbeat or palpitations are relieved. This results in lowering the rate and force of contraction of the heart.

How they work: They block the effect of the hormone epinephrine (adrenaline).

Beta-blockers (also called beta-adrenergic blockers).

Side effects: Confusion, dizziness, drowsiness, unsteadiness, sleep disturbances, feeling disoriented, memory impairment, irritability, and aggression.

Examples: Valium ( diazepam), Ativan ( lorazepam), and Xanax ( alprazolam).

Raised GABA levels have a calming effect on nerve cells that relieve anxiety symptoms.

These drugs mainly act by increasing the levels of a chemical substance in the brain and spinal cord (neurotransmitter) called gamma-aminobutyric acid or GABA. How they work: The exact mechanism of action of benzodiazepines is not well understood.Benzodiazepines (also called tranquilizers).

The top 10 medications for anxiety are summarized below:

Here are the top 10 medications for anxiety, which aim to treat the associated symptoms rather than cure the disorder.

Best anxiety medication