Schizophrenia, Bipolar Disorder: A Common Cause?

Schizophrenia, Bipolar Disorder: A Common Cause?

I don't normally take too seriously anything that appears in the Independent (one of the lower quality left-wing newspapers in Britain), but they are quoting from recent scientific research that doesn't surprise me in the least:

Scientists have discovered a remarkable similarity between the genetic faults behind both schizophrenia and manic depression in a breakthrough that is expected to open the way to new treatments for two of the most common mental illnesses, affecting millions of people.

Previously doctors had assumed that the two conditions were quite separate. But new research shows for the first time that both have a common genetic basis that leads people to develop one or other of the two illnesses.

Three different international studies investigated the genetic basis of schizophrenia by pooling their analysis of about 15,000 patients and nearly 50,000 healthy subjects to find that thousands of tiny genetic mutations – known as single nucleotide polymorphisms (SNPs) – are operating in raising the risk of developing the illness.

Each mutation on its own increased the risk of developing schizophrenia by about 0.2 per cent but collectively they were found to account for at least a third of the total risk of developing schizophrenia. The condition is known to have a strong inherited component, accounting for about 80 per cent of the total risk, but it is also influenced by upbringing and environment.

However, one of the most surprising findings to emerge from the three studies was that the same array of genetic variations in SNPs was also linked with bipolar disorder, a discovery that is at odds with the orthodoxy in psychiatry stating that the two conditions are clinically distinct, the scientists said. The findings are a milestone in the understanding of both schizophrenia and manic depression – also known as bipolar disorder – which could eventually lead to new ways of either preventing or treating conditions that cause untold human misery and cost the NHS hundreds of millions of pounds each year.

"If some of the same genetic risks underlie schizophrenia and bipolar disorder, perhaps these disorders originate from some common vulnerability in brain development," said Thomas Insel, director of the US National Institute for Mental Health in Bethesda, Maryland, which part-funded the studies. "Of course the big question then is how some people develop schizophrenia and others develop bipolar disorder."

I don't find this surprising because both schizophrenia and bipolar disorder run in my family, causing a lot of suffering and grief to those affected and their family members. In addition, some of those suffering from the extreme mania of bipolar disorder experience hallucinations that is called schizoaffective bipolar disorder. Finding a common cause may make it easier to find cures (as opposed to symptom treatment medicines) for both.