Dr Tomas Hajek, a psychiatrist and researcher from Dalhousie University, Nova Scotia, Canada, was in England recently, talking about his latest research on bipolar disorder. He had some fascinating answers to my questions.

Dr Tomas Hajek, psychiatrist and reseacherYou mentioned in your lecture the story of a woman who suffered a stroke which had unexpectedly beneficial consequences for her bipolar disorder. Could you explain what happened?

This was an interesting case of a woman with the diagnosis of bipolar disorder who suffered from severe, incapacitating and persistent episodes of depression and anxiety, which were not responding to treatments with medications.

One day she developed bleeding into her brain, which required surgery. She was fortunate to recover from this life-threatening event with essentially no neurological consequences. The surprising thing was that since the event, the symptoms of her bipolar disorder have subsided. She is no longer depressed or anxious. She went back to school and returned to normal functioning. Seven years following her stroke, the patient continues to experience a complete remission. She said: “It is just inconceivable that I could be depressed and anxious again but if they came back, I would want another stroke. I am just so grateful that the stroke gave me my life back”.

Case reports are considered a weaker source of information than studies of groups of patients, but we can still learn a lot from them. In this case a severe injury which altered the structure of the patient’s brain also alleviated the symptoms of her bipolar disorder, which previously hadn’t responded to standard treatments.

To anyone who needs persuading, this case shows that bipolar disorder is an illness of the brain. It also suggests that by learning more about the brain, we may be able to uncover novel treatments for this condition.

Your recent brain imaging work seems to support the argument that Lithium is beneficial in more ways than just controlling symptoms. Could you comment on that?

Lithium continues to be the gold standard for treatment of bipolar disorders, although not all patients respond to it. Even after more than 60 years of use, it keeps surprising us with new clinical effects. There is a large body of evidence showing that treatment with Lithium may protect nerve cells from various kinds of damage, so-called neuro-protective effects.

In several studies, patients not treated with Lithium shows smaller volume of brain grey matter (the part of the brain containing nerve cells) relative to Lithium-treated patients, who had comparable or even larger grey matter volumes than controls. In follow-up studies, patients had larger grey matter volumes after Lithium treatment. According to some studies this had beneficial effects on memory.

Lithium has even been tested in the treatment of neurodegenerative disorders. Although the results have been mixed, according to some studies, Lithium may even slow the cognitive decline in the early stages of dementia. We need more research into this novel and exciting use of Lithium.

How do you think brain imaging might be used as a diagnostic tool in the future?

Several of my patients have found it surprising that diagnosis in psychiatry continues to be based purely on description of symptoms and not on any laboratory tests. The relatively new field of neuroimaging allows us to safely visualise and measure the structure, function and biochemical composition of the living brain.

The hope that neuroimaging would help us develop diagnostic tests has not yet been fully realised. Perhaps even the best tools we currently use are still too blunt to cut into the mysteries of the human brain, which is the most complicated matter in the known universe. At the same time we are making progress.

To me, the most important use of neuroimaging would be to help identify people who are at a high risk for developing psychiatric disorders. This would allow us to start treatment early and perhaps arrest the onset or progression of the disease.