Mood stabilizers are not the same thing as antidepressants although both classes of medications are sometimes used to treat the various forms of depression. Where antidepressant medications function to lift mood up out of a depressive episode, mood-stabilizing medications help to regulate mood and keep it from fluctuating either too high (into mania) or too low (into depression).
The oldest and best mood stabilizer is lithium carbonate (lithium). Although this medication is primarily used to treat bipolar disorders, lithium can also be effective in alleviating unipolar depressive symptoms. Sometimes, lithium is added on to an antidepressant medication regimen for Major Depression when antidepressants alone are not working out.
Lithium is not a fun medication to take. Typical side effects of lithium include tremors, weight gain, heavy urination, excessive thirst, decreased coordination, reduced memory and concentration, changes in hair quality and quantity, nausea or diarrhea, decreases in sexual desire and function, and an increase in white blood cells. Lithium treatment also reduces thyroid function, preventing the release of thyroid hormones, which may make depression worse.
Lithium is also a potentially dangerous drug in that its therapeutic dose (the dose necessary for it to offer antidepressant effects) is uncomfortably close to its toxic dose. Toxic levels of lithium in the blood can cause slowed or stopped breathing, seizures, coma and even death. Before taking lithium, a person will undergo a battery of laboratory tests including a complete blood count, tests for serum creatinine, electrolytes, and hormones, and a urinalysis. A complete blood count measures the number of red and white blood cells and platelets to ensure that these cells are at normal levels, there are no known infections, and that the body can function normally in case of an injury. Measuring creatinine in blood serum is a test for kidney function. Since adequate kidney function is essential to clearing lithium from the system, this test is particularly important. Tests for electrolytes, hormones, (thyroid, in particular) and urine components indicate the basic health of an individual and provide baseline levels for comparison during lithium treatment. To avoid lithium toxicity, people must have regular monitoring of their blood levels of lithium to make sure that they remain within an acceptable therapeutic range. Blood lithium levels need to be monitored more frequently during the early stages of treatment, but as treatment stabilizes, monitoring can occur every three to six months.
Lithium is by no means the only mood stabilizing medication in use today. Please consult our Bipolar Disorder topic center for a more complete list of mood stabilizing medications.