People with bipolar disorder are more likely to get Parkinson's
Bipolar disorder patients are more than THREE TIMES more likely to get Parkinson’s, major review finds
- Those with bipolar faced an increased risk of more than three times
- Researchers combined results of seven studies, involving UK and US people
- They theorise the role of dopamine in the two diseases is what links them
Bipolar disorder patients may be more likely to get Parkinson’s, a major review of evidence has suggested.
Scientists uncovered the link after they analysed the results of seven studies involving 4.3million participants.
Patients with the mood disorder were more than three times more likely to end up with Parkinson’s, according to the findings.
Scientists at the Faculdade de Medicina da Universidade de Lisboa in Portugal did not prove bipolar disorder causes the crippling condition.
However, they believe drugs bipolar patients have to use for years to control their disorder could be to blame.
Another suggestion is that bipolar disorder may lower levels of dopamine, and a lack of dopamine is the main cause of Parkinson’s.
People with bipolar disorder are up to three times more likely to get Parkinson’s
Charities today welcomed the evidence published in JAMA Neurology – but warned the risk of a bipolar patient developing Parkinson’s is still slim.
Dr Patrícia Faustino and colleagues combined the results of seven existing studies that investigated the prevalence of Parkinson’s in bipolar patients.
One was conducted in the UK, involving more than 3,000 people, and another took place in the US and had more than 3.4million people.
The findings suggest that a previous diagnosis of bipolar disorder was linked with a 3.35 increased likelihood of Parkinson’s.
A second analysis suggested bipolar patients face a 3.21-fold higher risk of getting the condition.
WHAT IS BIPOLAR?
Bipolar disorder is a brain disorder which causes unusual and often sudden changes in mood and energy levels.
WHAT ARE THE SYMPTOMS?
Moods of those with bipolar disorder range from periods of extreme elation and energy (known as a manic episode) to periods of extreme somberness and lack of energy (known as a depressive episode).
HOW IS IT DIAGNOSED?
According to the International Bipolar Foundation, sufferers are diagnosed with rapid cycling if they have four or more manic, hypomanic, or depressive episodes in any 12-month period.
This severe form of the condition occurs in around 10 to 20 percent of all people with bipolar disorder.
WHAT CAUSES IT?
Currently it is unknown what is the cause of bipolar disorder, which affects around 5.7 million US adults aged 18 or older.
Scientists say genetics could play a role or that those with a a family history of bipolar disorder are more likely to have it.
The researchers said the link may be explained by the drugs bipolar patients have to take.
Bipolar causes extreme highs and lows, called manic and depressive episodes, which can interfere with daily life.
It’s usually diagnosed in teenagers, meaning patients are forced to take medication every day for the rest of their life to try and prevent a switch in mood.
The most common mood stabilisers prescribed in the UK contain lithium, taken for at least six months.
It is lithium, which, over long periods of time, may induce Parkinson’s, the researchers said.
About seven per cent of people with parkinsonism – a term that covers several conditions including Parkinson’s – have developed their symptoms following treatment with particular medications, according to Parkinson’s UK.
Any drug that blocks the action of dopamine, referred to as a dopamine antagonist, is likely to cause parkinsonism.
The link may also be explained by the role of dopamine – a chemical responsible for controlling brain functions – in both disorders.
Scientists are still unsure on the causes of bipolar disorder – but some suggest that the manic phases are caused by an imbalance of dopamine.
During a depression phase, dopamine is lower. This is then later compensated with a surge during a manic phase.
It is thought this may lead to an overall shortage of dopamine production – one of the first typical signs of Parkinson’s.
A reduction in dopamine is what leads to the symptoms of involuntary shaking, slow movements and stiffness.
However, Dr Faustino and colleagues made clear the relationship between bipolar and Parkinson’s ‘remains elusive’.
Dr Beckie Port, research manager at charity Parkinson’s UK, said: ‘A number of studies have now shown a potential link between bipolar disorders and an increased risk of Parkinson’s.
‘This analysis gives us the best indication so far of the level of increase in risk, however, even with a three fold increase, the risk of someone with bipolar developing Parkinson’s is still relatively low.
‘The association between the two conditions likely involves dopamine, which plays a complex role in brain signalling, from coordinating movement to regulating our moods.
‘Further research is needed to develop our understanding of this association and to turn that into a treatment that may, one day, prevent Parkinson’s.’
The findings echo that of a study in Taiwan, published in the journal Neurology, in May this year.
Researchers at the Taipei Veterans General Hospital found 0.7 per cent of bipolar patients got Parkinson’s, while only 0.1 per cent of the general population did.
The scientists suspected factors like inflammation, genetics and miscommunications between brain cells may be to blame.
Parkinson’s is caused by a loss of nerve cells in part of the brain called the substantia nigra, which leads to a reduction in dopamine.
But exactly what causes the loss of nerve cells is unclear.
The condition strikes one million Americans and 148,000 Britons, according to figures.
Like Parkinson’s, an incurable neurological disease, there are many gaps in the understanding of bipolar.
The disorder affects some 5.7million people in the US, according to estimates.
It’s fairly common in the UK, the NHS say. One in every 100 people will be diagnosed with it at some point in their life.
PARKINSON’S PATIENTS WILL TRIAL CBD FOR HALLUCINATIONS
Parkinson’s patients will trial cannabidiol (CBD) – a compound found in the cannabis plant – to treat hallucinations.
Between 50 and 60 per cent of the 145,000 people living with Parkinson’s in the UK will be affected by psychosis at some point in their life.
This is the first large-scale trial which will aim to provide evidence for the potential benefits and safety of CBD to alleviate the symptoms of Parkinson’s-related psychosis.
Parkinson’s UK, the largest charitable funder of Parkinson’s research in Europe, is partnering with King’s College London and investing £1.2million in the phase II clinical trial.
The study is scheduled to start in early 2020 and will begin with a six-week pilot to find the optimum dose of CBD.
In the second stage, 120 people with Parkinson’s-related psychosis will be recruited to take part in a 12-week double-blind, placebo-controlled study.
Half the group will receive CBD and half a placebo.
Researchers will then carry out detailed assessments of psychotic, motor and non-motor symptoms. Brain imaging will be used to investigate the effects of CBD.
Lead Researcher Sagnik Bhattacharya, Professor of translational neuroscience and psychiatry at King’s College London, said: ‘Current treatments prescribed by clinicians for psychosis, typically work by blocking dopamine receptors which can increase the problems people with Parkinson’s experience with movement and other symptoms of the condition.’
Dr Beckie Port, research manager at charity Parkinson’s UK, said: ‘We know that people living with Parkinson’s are desperate for new treatments that can better manage their symptoms, and undoubtedly, CBD oil is something the community is interested in.
‘We hope that this large-scale trial will provide much needed evidence in the treatment of Parkinson’s-related psychosis.’
Dr Port said anyone with Parkinson’s considering using CBD should speak with their doctor.
Source: Read Full Article