Psychiatric researchers at the  University of Adelaide are developing gene-based tests for personalized treatment for people with bipolar disorder . The hope is that genetic and blood test information could help determine which drug may work best for a patient, and what should be avoided.University of Adelaide

When depressed, people with bipolar have a low mood, poor energy levels, and lose interest in pleasurable activities. They also notice negative negative thoughts about themselves and their environment. In the most severe cases, people lose their appetite, are unable to sleep, and have thoughts that circle around death and suicide.

During manic episodes, patients become increasingly unpredictable and engage in activities that are often "out of character". As mania progresses, patients can become irritable, impatient, and aggressive towards others. Often they find themselves in conflict with their family or people at work.

Depressive and manic episodes can occur within short periods of time, or after long periods of normal mental health. A range of drug treatments are available, but choosing the right medication, or range of medications, can be a struggle – sometimes spanning many years.

Most patients with bipolar disorder are prescribed " mood-stabilizing " medication for treatment during episodes and to prevent relapse. This usually consists of one, or a combination, of three types of medicine: lithium salts, anti-epileptic medicines such as sodium valproate, and some "antipsychotics" such as risperidone, quetiapine, or olanzapine.

It's hard to predict which drug will work best for each person, so these treatments are generally selected by trial and error. It can take years until the optimal medication is determined. So psychiatric research labs are now developing tests for personalized drug selection for people with bipolar. 

A focus of these research efforts is the mood stabilizer  lithium , is seen as the "gold standard" treatment for bipolar. It is useful in treating acute mania, protects against further illness episodes, enhances antidepressant treatments, and can prevent suicidal thoughts and actions.

But only 30% of bipolar patients experience the full range of lithium benefits. For some others, additional medicines have to be added to control the illness. And about 30% of bipolar patients get no benefit at all from lithium, and need to use other types of mood stabilizers.

Responsiveness to lithium can run in families. A patient is more likely to do well on the drug if their parent or sibling (if they also suffer from bipolar disorder) also shows a good response. This suggests a genetic , or heritable, component to the medication response.

Research from our group and others have now begun to untangle the underpinnings of these genetic effects . We found that "bipolar" patients who carry many "risk" genes for certain other medical and psychiatric disorders, such as schizophrenia, are less likely to have a good outcome with lithium.

Further, to a large-scale genetic study we were involved in finding a small number of genes that specifically determined lithium response. Other studies are starting to uncover the biological effects of these genetic variations . There is increasing evidence, for instance, that people who have well on lithium have specific disturbances in molecular pathways  that regulate energy within nerve cells.

These studies suggest people with bipolar illness have a " biological signature " that can predict how they will respond to different mood stabilizing medicines. But much work needs to be done, over several years, before these findings can be translated into tests that can be run routinely in psychiatric clinics.