Lithium was discovered to be effective in treating elevated mood in 1949 by the Australian psychiatrist John Cade. Lithium is used to treat elevated mood (mania) and depressed mood (depression) in people with bipolar affective disorder. Lithium also increases the effectiveness of antidepressant medications. It is given with antidepressant medications to treat depression in people who are depressed but do not experience episodes of elevated mood. (Lithium can also be used to decrease aggression, self-injury and steroid-induced psychosis.) Lithium is also effective in treating depression in people with major depression who do not become manic or have bipolar disorder; however, antidepressants are more effective and have fewer side effects.
Lithium is thought to have an effect via several mechanisms. It substitutes for some of the sodium, potassium, magnesium and calcium ions that pass in and out of the nerve cells in the brain (neurons). It also has an effect inside the brain cells by altering the mechanism of the cell and altering the chemical communication between cells. Lithium can change the quantity of neurotransmitter receptors on cells, and this might be the mechanism by which lithium helps other drugs stop depression. Lithium has been shown to protect neurons in the brain, and to restore the amount of cells in the hippocampus, a part of the brain that might be effected in some people by depression and/or posttraumatic stress disorder.
Lithium is one of only two drugs that have been shown to decrease the risk of suicide. This effect is not fully explained by its ability to make mood normal. Lithium is the third element of the periodic table. Technically, lithium is a metal; it is given as a salt, the same way iron in iron tablets is given as a salt.
In Australia, lithium is sold in standard and slow-release preparations. The standard preparation is called Lithicarb and the slow release formulation is called Quilonum SR. The slow release preparations cause fewer side effects but are more expensive for the government; Quilonum is available in public hospitals only with a prescription to a community pharmacy. Lithicarb comes in 250mg tablets and Quilonum comes in 450mg tablets; this helps stop mix-ups about which type of lithium tablets someone is on.
Lithium can be taken once or twice a day. Taking it twice a day might increase its effectiveness. Taking it once a day is easier to remember. A dosette box helps people to remember to take their tablets. A dosette box is a box with separate compartments where tablets are stored for each day of the week, and sometimes, time of the day. They can be bought from the pharmacy were you get your medication. If even more help is needed, a pre-packaged Webster Pack containing tablets for two weeks can be obtained from the pharmacy where you get your medication. If you miss a dose of lithium, you should not take an extra one the next day to catch up.
Before, or shortly after you start lithium, you need to have blood tests that check the function of your thyroid gland and kidneys, your levels of calcium, phosphate and glucose, and to ensure that you are not pregnant. An ECG (electrocardiogram) might be done to check the electrical impulses of your heart. This is done by briefly attaching recording wires across your chest and to your arms. You should have a physical examination done by a doctor, such as your GP, before, or shortly after, you start taking lithium. Some authorities recommend that lithium treatment is started in hospital, but this is not necessary.
Lithium should not be stopped suddenly except in an emergency. It should be stopped over 1 to 2 months. If lithium is used to treat BPAD, stopping it suddenly can cause an episode of manic, elevated mood.
There is some evidence that if lithium is stopped, it will not work as well for elevated mood when it is restarted. It is also possible that intermittent treatment with lithium makes the overall course of bipolar disorder worse. This means that once lithium is started, it should only be stopped after careful consideration. Talk to your doctor before you stop the lithium (unless there is an urgent reason to stop the lithium). In one study, stopping lithium increased the risk of suicide twenty fold.
Side Effects of Lithium that Start Soon After Treatment
The side effects of lithium that might start soon after treatment are listed below. Most are not common.
- Fine tremor, especially of the hands
- Muscle weakness
- Thirst, which causes increased fluid intake and urine production
- Memory and concentration problems
- Changes in creativity
- Weight gain
- Epileptic seizures
- Psoriasis, acne and/or follicular keratosis (a lumpy rash)
- Muscle stiffness or increased muscle tension
The tremor that is caused by lithium usually stops with time. On the other hand, it worsens during activities that need fine control. The tremor can be reduced by stopping caffeine (tea, coffee, cola, energy drinks, chocolate), decreasing anxiety, and by taking medications called beta-blockers. Beta-blockers include medications such as atenolol. Beta-blockers should not be taken by people who have insulin-dependent diabetes, asthma, heart failure, heart rhythm/ECG (electrocardiogram) disturbances or low blood pressure. Lithium also rarely causes a tremor like the one that occurs with Parkinson’s disease.
Thirst can be decreased by taking lithium once a day.
Lithium can cause thinking and memory problems. On the other hand, studies of writers and artists found that most of them were more creative when they were taking lithium, because they were more organized. Some people feel inspired by having a high mood and others just enjoy the feeling of being high. This is unfortunate as the best thing for thinking and concentration is to have a mood that is neither elevated nor depressed.
Lithium can decrease the seizure threshold. That is, it can make epilepsy worse, and if you do not have epilepsy, there is a very slight chance that you could have an epileptic seizure. However, this is not usually a reason to stop people driving or to make them have supervised baths when they start taking lithium.
There is a theoretical risk of the side effect of tightening of the muscles in the throat making it hard to breath. Lithium can also change the electrical reading of the heart when an ECG recording is make; this is of little practicable significance.
Alcohol and Lithium
Because lithium causes drowsiness, it increases the effect of alcohol. This is especially important in driving, operating machinery, caring for children or walking near traffic. For example, if your blood alcohol level was 0.05, you might be just as impaired as if your blood alcohol level was, say, 0.08 and you were not taking lithium. (If there are doubts about driving, driving ability can be tested by occupational therapists.) Lithium also increases the drowsiness caused by other medications, such as antihistamines and benzodiazepines, or by other things, such as missing sleep.