Anxiety in Parkinson’s may be linked to changes deep inside the brain

Anxiety in Parkinson’s is not simply a reaction to living with a difficult disease. New research suggests it is linked to biological changes in the brain itself. A study published in npj Parkinson’s Disease used an extremely powerful 7 Tesla MRI scanner to examine the brains of people with early Parkinson’s. The researchers found differences in several deep brain structures in people who had significant anxiety compared with those who did not. The strongest finding involved the caudate, a brain structure involved in movement, learning, motivation and behaviour. People with Parkinson’s who had more severe anxiety tended to have a smaller caudate on both sides of the brain. The researchers also found differences in the shape of the caudate, the amygdala, the thalamus and the nucleus accumbens. These areas are part of brain networks involved in emotions, fear, motivation and how we respond to what is happening around us. The amygdala, for example, plays an important role in detecting and responding to threats. The findings help explain why anxiety can be such a significant part of Parkinson’s. Parkinson’s does not only affect the brain areas responsible for movement. It can also affect the networks involved in mood, emotions and the response to stress. The researchers used 7 Tesla MRI, which produces much more detailed images than standard MRI scanners. This allowed them to look closely at the size and shape of small structures deep inside the brain. Importantly, the study does not prove that these brain changes cause anxiety. The researchers looked at people at one point in time, so they cannot tell whether the changes came before the anxiety or developed alongside it. More research following people over time is needed. But the message is important: anxiety in Parkinson’s is not simply something a person is imagining or failing to cope with. There are physical changes in the brain that may be part of the reason it happens. Understanding these changes could eventually help researchers develop better ways to recognise and treat anxiety in people with Parkinson’s.