Depression affects over 16 million Americans per year. Prescription lithium (Eskalith, Lithobid) has been used for decades to treat some mental health conditions, including bipolar disorder depression. Oral lithium (also called lithium carbonate) is derived from the natural element lithium. This is found in nature and is the lightest known metal.

As new prescription drugs enter the marketplace, the use of prescription lithium has declined. This isn’t so much because of the drug’s efficacy. It’s more related to the potential unwanted side effects that lithium can cause.

Even after more than 50 years of clinical use, it’s still not completely clear why (and to what extent) lithium works to treat the symptoms of bipolar disorder.

Lithium appears to be particularly effective for the long-term management of bipolar disorder. This is because it can reduce the number of manic episodes or suicidal thoughts that a person with this condition would otherwise have.

Doctors do know that lithium targets the central nervous system. Lithium increases the amount of certain chemicals in your brain which help to balance mood.

Some researchers believe that using lithium helps strengthen the nerve connections in your brain that control your mood because of proteins it contains.

Lithium does have a strong clinical track record as an effective treatment for bipolar depression. Specifically, over 300 studies in a clinical review showed that lithium use notably suppressed suicide attempts and suicides in study participants.

Since people who have clinical depression and mood disorders are 30 times more likely to attempt suicide than people without, the findings of these studies are significant.

Lithium’s connection to a lower suicide rate for people with bipolar depression suggests that it suppresses other symptoms of the condition, too. Researchers take these findings as evidence that lithium’s mood-stabilizing effects are the reason why people who take it have less manic episodes and fewer suicidal thoughts. For this reason, lithium may also work as a short-term treatment option for people who have acute manic episodes.

Lithium is only approved for depression associated with bipolar disorder. It might also be effective for other kinds of depression when it’s added on to an antidepressant, but more trials are needed. If you’re taking an antidepressant and still have symptoms, talk to your doctor about whether adding lithium could help.

Lithium is safe to take if you’re under a doctor’s close supervision and if you’re in a stable environment where you can take the medication consistently.

Although lithium the metal is often used to make batteries, the lithium carbonate used in lithium drugs has a different ionic charge. Your body absorbs lithium in a similar way to how it absorbs sodium, which is also an alkaline metal.

Lithium is not safe for children under the age of 7 or for pregnant or breastfeeding women. Lithium is also not safe if you have the heart condition Brugada syndrome.

Lithium can interact with quite a long list of medications, including many other psychotropic drugs. Discuss all medications you’re taking, including over-the-counter drugs and supplements, with your doctor.

Dosing for lithium varies according to your age, weight, and medical history. This medication should be taken with care, and only according to your doctor’s specific instructions.

Oral lithium comes in capsules, a liquid solution, and extended-release tablets.

It can take several weeks for lithium to start to take effect when using it to treat bipolar depression. A standard dose of oral lithium for an adult is 600–900 milligrams, taken two or three times per day.

To protect you from side effects and make sure you’re not getting too much medication, your doctor will draw blood to monitor your lithium levels.

Almost everyone who takes lithium experiences side effects to some degree. Not everyone will experience all of these side effects, but it’s likely you’ll experience some of these common side effects if you’re prescribed lithium:

  • frequent urination
  • unusual thirst
  • dry mouth
  • sudden irritability
  • a false sense of well-being/invincibility
  • confusion or lack of awareness of your surroundings
  • weight gain
  • fatigue and lethargy
  • poor short-term memory
  • stiffness in your limbs
  • shaky or twitching hands (tremor)
  • nausea or vomiting
  • headaches

Less common side effects include:

  • blurred vision
  • chills
  • dizziness/vertigo
  • loss of appetite

If you’ve been prescribed lithium, take it carefully according to your doctor’s directions. Lithium can be toxic if you overdose on this drug. Symptoms of lithium toxicity include:

  • tremors
  • loss of muscle control
  • dehydration
  • slurred speech
  • excessive drowsiness

If you’re experiencing any of those symptoms as a result of taking lithium, you may be having a medical emergency. Call 911 or have someone take you to the emergency room. Don’t attempt to drive.

There are cases when suicidal thoughts or bipolar tendencies become temporarily, or permanently, worse when you start taking lithium. If you feel that your symptoms are worsening, call the doctor who prescribed lithium to you and discuss your options.

If you’ve been diagnosed with bipolar depression, don’t stop taking lithium or any prescription antidepressant cold turkey. Any change in your treatment should be done under a doctor’s close supervision and take place gradually.

Lithium isn’t safe for pregnant women. It’s important to use birth control to prevent pregnancy while you take this drug. If you’re taking lithium and believe you might be pregnant, communicate with your doctor right away.

Lithium is most often prescribed for people who need a long-term strategy to manage bipolar depression. Use of oral lithium puts you at risk of serious side effects, which makes it less popular than other treatment options.

But lithium, when used correctly, has also been shown to be incredibly effective for the management of bipolar depression symptoms — even if doctors don’t completely understand why. Lithium toxicity is rare, but it can occur, so always follow your doctor’s directions when taking oral lithium.