Lithium treatment — the key facts

When is lithium used?

Lithium is a mood stabiliser — a medicine that levels out mood both when it is too high (mania) and too low (depression). It works well in treating episodes of bipolar disorder, but its main role is prevention: it protects people who are already in remission from another episode.

International societies regard lithium as the first-line treatment for preventing relapse. It has the strongest evidence of effectiveness of all mood stabilisers and is one of just two psychiatric medicines with a proven effect in protecting against suicide.

Bipolar disorder lasts a lifetime, so long-term effects matter. In a study covering the whole population of Finland, lithium not only protected against relapse but also halved the mortality of the people taking it. It is today the best long-term option for treating this illness.

Lithium can also help in other conditions — for example in treatment-resistant depression or as an addition to the treatment of schizophrenia.

What are the additional benefits of lithium?

Beyond stabilising mood, lithium acts on the brain in several other ways, which helps explain its effectiveness.

It protects brain cells from premature death and supports their work. It also stimulates the formation of new neurons, among others in the hippocampus — the structure responsible for memory, cognitive ability and resilience to stress. As a result it not only improves how the brain functions but also protects against dementia.

Lithium also eases inflammation — both in the brain and throughout the body. The inflammatory response is the body’s natural defence against threats, but when it becomes excessive it can do harm. By lowering its activity, lithium may have a beneficial effect on the course of the related illnesses.

Individual studies further point to a protective effect of lithium on DNA, a slowing of ageing and a lower risk of cancer, heart attacks and strokes.

How is lithium taken and what tests are needed?

Before starting

Before starting treatment we run blood tests that assess general health and the function of the kidneys and thyroid.

Starting the medicine

Lithium is taken as tablets, and under the latest guidelines usually once a day, in the evening. We start with a small dose to limit side effects and to get used to the treatment calmly. We set the right dose based on the lithium level in the blood — at the start, tests may be needed every week or two.

Maintenance treatment

Once the right dose is set, we move to maintenance treatment. We then monitor the lithium level and the function of the kidneys and thyroid — two to four times a year, always in the morning, about 12 hours after the evening dose.

How long does lithium treatment last?

The length of treatment depends on the person and the indication. Most patients with bipolar disorder need long-term treatment with at least one mood stabiliser. Lithium lets many of them reach lasting remission and improve their general health.

How well is lithium tolerated?

Like any medicine, lithium can cause side effects — but, contrary to the myths, it is one of the better-tolerated mood stabilisers. It causes tiredness less often than other medicines and has a weaker effect on body weight, and patients stop taking it less often.

The intensity of side effects depends strongly on the lithium level in the blood. A lower level means fewer complaints, but also a weaker protective effect. That is why we measure the level regularly — especially at the start — to find the balance between effectiveness and comfort of treatment.

The most common side effects

The most common are tremor, increased thirst and nausea. They usually ease with time, and reducing the dose further improves tolerance.

Increased thirst and more frequent urination affect more than half of patients. It is worth replacing fluids with calorie-free drinks (water, tea, coffee) so as not to gain weight.

Cutting down on caffeine reduces tremor; vitamin B6 or adding a beta-blocker can also help. Nausea appears in the first days or weeks in about a third of patients — taking lithium with a meal, or ginger, eases it.

Possible complications

Reduced kidney function

Over time lithium may slightly worsen kidney function, so we check it before treatment and then every six months to a year. The latest research shows that even if kidney function declines, it does not lead to kidney failure. Lithium does not affect the liver.

Reduced thyroid function

In 1–2 people in 10, lithium reduces the secretion of thyroid hormones, which can cause tiredness, weight gain, dry skin or sensitivity to cold. We monitor thyroid function throughout treatment, and any hormone shortage is easy to make up.

Excess calcium

A rare complication that can show as nausea, a loss of appetite or excessive urination. We check the calcium level before and during treatment.

Heart rhythm disturbances

A rare complication; in people at cardiac risk we monitor it with an ECG.

This article is for information only and does not replace a medical consultation. Lithium treatment is always decided by the doctor together with the patient.