A simple blood test can identify people coping with bipolar disorder (formerly known as manic depression) and can predict the efficacy of lithium, the drug given to patients with this disorder. These findings emerge from a new study conducted at the University of Haifa and published in the prestigious journal Molecular Psychiatry , part of the Nature group. “For the first time, the findings of the study enable us to use a blood test to find out – within a short timeframe of a few days, and at a relatively low cost – whether a person is suffering from bipolar disorder. We can also predict the efficacy of lithium, the drug given to people coping with bipolar disorder, and to adjust the medication individually,” explains Dr. Shani Stern of the University, the corresponding author of the study.

Bipolar disorder, better known by its former name manic depression, is a chronic psychological disorder characterized by recurrent, sharp changes in mood, oscillating between extreme happiness and sadness and depression. The prevalence of the condition among the adult population around the world is between one and three percent and the average age of onset is 19 years. At present, the evaluation of the level of bipolar disorder is undertaken by a specialist physician in the field of psychiatry, and includes questions intended to determine whether or not the patient has bipolar disorder and what is the most effective treatment in their case. One of the commonest treatments is lithium, but only around one-third of patients respond to this drug. Dr. Stern notes that due to the strong similarity between manic depression and other disorders, such as schizophrenia, there is a risk of misdiagnosis, at least in the early stages. Moreover, at present there is no way to know in advance whether or not lithium will help an individual patient.

The current study was undertaken by Dr. Stern and her research team that included research students Liron Mizrahi and Ashwani Choudhary from the Sagol Department of Neurobiology at the University, in collaboration with Dalhousie University and the Salk Institute. The study sought to examine whether it is possible to use a blood test to identify a person suffering from bipolar disorder and to predict the efficacy of lithium treatment for that individual. The study examined cells from three different groups in the population: people who are not suffering from bipolar disorder; people who are suffering from bipolar disorder and who respond to lithium treatment; and people suffering from the disorder who do not respond to lithium.

In the first stage of the study, white blood cells isolated from all the participants were examined; a cell culture is produced that can be maintained for a long period by infecting the cells with the EBV virus, which causes mononucleosis. In the second stage the researchers extracted RNA from the cells in order to understand which genes are expressed in each population and to identify genes that are expressed differentialy.

The findings show that 80% of the differences in gene expression are related to the expression of immunoglobins, the chief components of the immune system. “The most significant finding is that in people suffering from bipolar disorder, a difference was found at the exression level of genes of the receptors to the antibodies; this may explain  the high rate of comorbidities. There is a known correlation between various psychiatric disorders and ancillary morbidity,” Dr. Stern noted.

After obtaining the biological findings, the researchers used a comutational model based on artificial intelligence comprising neural networks; the AI model was developed at Dr. Stern’s laboratory for the purpose of verifying the findings. The researchers also used cells from other laboratories that executed the same biological processes as in the current study in order validatethat the computational model also works for cells sampled in various laboratories.

The findings of the mathematical model were capable of predicting at a level of precision of over 90% whether an individual suffers from bipolar disorder, and whether they respond to lithium treatment. “This method can enable people coping with psychiatric disorders to save many months of suffering by adjusting the right medication for them,” Dr. Stern concluded.