Study: Unusual sensations, paranoia common in Parkinson’s patients
Experiences 'distressing' for some; treatment did not help, per researchers
Approximately two-thirds of Parkinson’s disease patients may experience paranoia and unusual sensations, including visual hallucinations, according to a new study from the U.K.
People with Parkinson’s may have paranoid thoughts or unfounded fears, as well as abnormal sensory experiences, the study found. Further, many of the individuals who had such experiences remain uncertain about the specific causes of these events and what factors contribute to their resolution.
For a small number of patients, “these experiences are distressing and not resolved by existing treatment,” the researchers wrote, noting, however, that such episodes “are common, even in those not taking dopaminergic medication” frequently prescribed for treating Parkinson’s.
“If support could be offered to help identify and intervene on triggers and modifiers — for example, using monitoring forms supported by Parkinson’s nurses — this may help to reduce the severity of [unusual sensory experiences] for some,” the researchers wrote.
The study, “Paranoia and unusual sensory experiences in Parkinson’s disease,” was published in the journal Aging & Mental Health.
Little information available on Parkinson’s paranoia, unusual sensations
While Parkinson’s is mostly known for its motor symptoms, it can also cause changes in mood, thinking, and behavior. Some of these nonmotor symptoms are common, and as many as half of Parkinson’s patients will at some point develop psychosis, data have shown. Psychosis is a complex condition characterized by a group of symptoms that impair an individual’s ability to differentiate between reality and distorted perceptions, thoughts, or beliefs.
Early in the course of Parkinson’s, patients often have unusual sensory experiences like seeing things that aren’t there, feeling like someone is nearby, or briefly noticing a person or animal out of the corner of their eye. Some individuals also have delusions, such as being afraid of abandonment or feeling jealous.
Because these experiences are not well studied, however, there is little information on them. That dearth of knowledge led a team, headed by researchers from the University of Oxford, to investigate how common, how severe, and how distressing they are. The researchers also explored the psychological factors that may be linked to unusual sensory experiences in Parkinson’s.
Their study involved 369 patients, ages 36 to 92 — with a mean age of 66 — who had a diagnosis of Parkinson’s for an average of 5.2 years. Among them, 10 (2.7%) also had a diagnosis of psychosis. The patients were recruited through Parkinson’s UK social media as well as local Parkinson’s groups, and asked to complete a questionnaire.
Most (93%) were taking medication such as levodopa or dopamine agonists, which work by increasing the levels or mimicking the action of dopamine in the brain. Dopamine is a chemical that signals for motor control, but it’s lost in Parkinson’s; such medications are commonly used to treat the disease. The other 24 patients were not taking any medication to treat their Parkinson’s.
Approximately two-thirds of patients had at least one paranoid thought or unusual sensory experience, and nearly half (49%) had at least one unusual sensory experience in the previous month. Fewer patients — 23% or nearly one-quarter — reported weekly unusual sensory experiences.
Common experiences for patients included seeing things out of the corner of their eye (29%), misinterpreting objects (26%), and presence hallucinations, or feeling a presence nearby (23%). Some also had nonvisual hallucinations, like hearing sounds (17%), feeling sensations (12%), smelling things (20%), or tasting things (6%) that weren’t there.
Triggers for some include being alone or low mood, but others were unsure
For nearly 1 in 4 patients, these experiences were distressing at a moderate or severe level.
“There was a clear subset (23%) of individuals for whom [unusual sensory experiences] were frequent, severe, and distressing, and additional support was desired,” the researchers wrote.
However, “conversely, for many individuals, the experiences were neither distressing nor associated with severe functional impact,” the team noted.
While dopaminergic medication can result in delusions or hallucinations as side effects, nearly half of untreated patients also had unusual sensory experiences, according to the researchers.
Having at least one paranoid thought in the past month was reported by nearly one-quarter of patients. These included fear of being abandoned (16%) or betrayed by their spouse (13% of those living with a spouse), “despite reassurance to the contrary,” the researchers wrote.
Among the Parkinson’s patients with paranoia, 19% felt moderate or severe distress from those thoughts.
There was a clear subset (23%) of individuals for whom [unusual sensory experiences] were frequent, severe, and distressing, and additional support was desired. … Conversely, for many individuals, the experiences were neither distressing nor associated with severe functional impact.
Symptoms of psychosis were more frequent among patients with depression, anxiety, bipolar disorder, or post-traumatic stress disorder, with nearly two-thirds (65%) reporting an unusual sensory experience. Vision or hearing problems were also common among those with visual or auditory hallucinations.
Triggers included nighttime/falling asleep (29%), being alone (24%), or low mood (13%). However, more than one-third of these individuals (35%) were unsure of what triggered their unusual sensory experiences. Most experiences were brief (49%) or lasted minutes (25%). Many ended naturally (33%) or through distraction (25%).
A small proportion of patients (12%) with unusual sensory experiences had received help, mostly in the form of medication. Among those with weekly unusual sensory experiences, 43% wanted more support, even if more than half (54%) said their daily life wasn’t affected.
The researchers noted that “having a family member around for support and to reassure or question experiences may help reduce distress.”
Several limitations of the study were noted by the team, including the use of “predominantly white-British” patients.
“Future research may benefit from more active outreach to individuals with [Parkinson’s] among the global majority,” the team wrote, noting that “a number of avenues for future longitudinal and intervention studies are clearly identified.”
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