This information is for people who have bipolar disorder. It tells you about lamotrigine, a treatment used for bipolar depression. It is based on the best and most up-to-date research.
Does it work?
Probably. Some research has shown that lamotrigine can relieve the symptoms of depression that you get with bipolar disorder. That is called bipolar depression.
What is it?
Lamotrigine is a drug that is mostly used to treat a condition called epilepsy. If you have epilepsy, you get seizures. Lamotrigine can prevent these. So you may hear it called an anticonvulsant drug. (Convulsion is the medical name for a seizure.)
Lamotrigine comes as tablets. The brand name is Lamictal.
Doctors can also use this drug to stop the symptoms of bipolar disorder from coming back. For more, see Lamotrigine to prevent a relapse.
How can it help?
People with bipolar depression who take lamotrigine are more likely to find that their symptoms get better or go away.
Taking lamotrigine may help you: 
A review of the research found that the benefits of lamotrigine were fairly modest for people with bipolar depression.  However, people who were more severely depressed improved the most.
The dose you take may be important. One study showed that only one quarter of people taking a dummy treatment (a placebo) felt better.  But more than half of the people taking 200 milligrams of lamotrigine a day felt better. People who took a lower dose, 50 milligrams a day, didn't do as well though.
How does it work?
We don't really know why a drug like lamotrigine that controls seizures should work for bipolar depression. We do know that some drugs in this group work for treating bipolar disorder, especially mania. Doctors think this may be because they calm down the activity in your brain.
Can it be harmful?
The study we found showed that some people got side effects when they took lamotrigine.  About 32 in 100 people taking lamotrigine got headaches, compared with 17 in 100 people taking a dummy treatment.
Lamotrigine can cause a rash.  Very occasionally, this can be serious and needs to be treated in hospital. Talk to your doctor straight away if you get a rash while you're taking lamotrigine.
Some other side effects that you might get are diarrhoea and double or blurred vision. You may also feel: Self-harm and suicide
There is a very small risk that taking lamotrigine might make you more likely to think about suicide or harming yourself.  If you are worried about any thoughts or feelings you have, see your doctor straight away.