Depression can appear years before a diagnosis of Parkinson’s disease or Lewy body dementia, new research has revealed, suggesting it may be an early indicator of neurological disease.
A long-term study found people who later developed Parkinson’s disease or Lewy body dementia were significantly more likely to experience depression than those with other serious chronic illnesses.
Lewy body dementia is a progressive condition caused by abnormal protein build-up in the brain, affecting thinking, memory and movement.
Parkinson’s disease also affects movement and mood due to the loss of dopamine-producing nerve cells.
The researchers wrote: “Following a diagnosis of Parkinson’s disease or Lewy body dementia, the persistent higher incidence of depression highlights the need for heightened clinical awareness and systematic screening for depressive symptoms in these patients.”
Researchers analysed health records from 17,711 people over 12 years, all of whom later developed Parkinson’s disease or Lewy body dementia.
hey were matched with people living with other long-term conditions that can also affect daily life.
The comparison groups included 19,556 people with rheumatoid arthritis, 40,842 with chronic kidney disease and 47,809 with osteoporosis.
Rates of depression began to rise around eight years before diagnosis of either neurological condition and remained higher for at least five years afterwards. The association was strongest for Lewy body dementia, which the researchers suggest may be linked to its faster progression and its effects on brain chemistry involved in mood.
The median age at diagnosis of Parkinson’s disease or Lewy body dementia was 75.
The researchers suggest that people diagnosed with depression for the first time later in life may benefit from assessment for early neurodegeneration, meaning the gradual loss of nerve cell structure and function.
The researchers wrote: “Given the established associations between depression, cognitive decline, and accelerated disease progression, early detection and treatment of depression in this patient population may be crucial.
“Integrating mental health assessments into routine neurological care may facilitate the timely initiation of antidepressant therapy or other appropriate interventions.”
