Adult ADHD Symptoms Increase Risk of Dementia With Lewy Bodies

Adults with symptoms of attention-deficit/hyperactivity disorder may be at increased risk for developing dementia with Lewy bodies as they age, according to a case-control study published in the European Journal of Neurology.

Patients who developed dementia with Lewy bodies (DLB) in older age had a history of ADHD symptoms in adulthood at more than three times the rate of healthy older adults or patients with Alzheimer’s disease, reported Dr. Angel Golimstok and colleagues at the Hospital Italiano Buenos Aires (Argentina).

The study is the first to establish a clear link between adult ADHD symptoms and DLB.

To investigate the possibility that ADHD symptoms may precede DLB, the researchers recruited a representative sample of patients with dementia and healthy controls from the membership of a large prepaid health maintenance organization model during 2000-2005. Two neurologists blinded to the purpose of the study used the DSM-IV and the Wender Utah Rating Scale to assess retrospective reports from family members or close friends about the patients’ previous symptoms of ADHD (Eur. J. Neurol. 2011;18:78-84).

Dr. Golimstok and associates determined that 52 (48%) of 109 patients with DLB had previously suffered from symptoms of adult ADHD, compared with 38 (15%) of 251 patients with Alzheimer’s disease (odds ratio 5.1) and 23 (15%) of 149 healthy control patients (OR 4.9). This meant that DLB patients were about five times more likely to have had ADHD symptoms than were Alzheimer’s disease patients or healthy controls.

Scores on parts of the rating scale that measured impulsivity and hyperactivity were significantly higher in patients with DLB, compared with both the Alzheimer’s disease and healthy control groups, they noted.

The investigators suggested that the association between ADHD symptoms and DLB may be explained by a common neurotransmitter pathway dysfunction. "In ADHD there are low levels of tonic [dopamine], and the abnormalities in [noradrenaline] may affect the maturation of central dopaminergic systems," they wrote. "This may be a risk factor for the development of DLB as well as Parkinson’s disease."

Although it is possible that both diseases may lie on a continuum of a single disease beginning with ADHD manifested in childhood and continuing into adulthood as DLB "when neuronal loss and gliosis in the substantia nigra, locus coeruleus, and nucleus basalis of Meynert occur," the authors doubted that this hypothesis could be true, because low dopamine levels in ADHD are not initially associated with Parkinsonlike or DLB symptoms.

The study findings may be limited by several factors, including the possibility that ADHD may occur more frequently in individuals with a personality type that could be linked to DLB or that "ADHD exposure could be a reflection of DLB not yet recognized," the authors stated.

The authors disclosed having no relevant financial conflicts.

Adults with symptoms of attention-deficit/hyperactivity disorder may be at increased risk for developing dementia with Lewy bodies as they age, according to a case-control study published in the European Journal of Neurology.

Patients who developed dementia with Lewy bodies (DLB) in older age had a history of ADHD symptoms in adulthood at more than three times the rate of healthy older adults or patients with Alzheimer’s disease, reported Dr. Angel Golimstok and colleagues at the Hospital Italiano Buenos Aires (Argentina).

The study is the first to establish a clear link between adult ADHD symptoms and DLB.

To investigate the possibility that ADHD symptoms may precede DLB, the researchers recruited a representative sample of patients with dementia and healthy controls from the membership of a large prepaid health maintenance organization model during 2000-2005. Two neurologists blinded to the purpose of the study used the DSM-IV and the Wender Utah Rating Scale to assess retrospective reports from family members or close friends about the patients’ previous symptoms of ADHD (Eur. J. Neurol. 2011;18:78-84).

Dr. Golimstok and associates determined that 52 (48%) of 109 patients with DLB had previously suffered from symptoms of adult ADHD, compared with 38 (15%) of 251 patients with Alzheimer’s disease (odds ratio 5.1) and 23 (15%) of 149 healthy control patients (OR 4.9). This meant that DLB patients were about five times more likely to have had ADHD symptoms than were Alzheimer’s disease patients or healthy controls.

Scores on parts of the rating scale that measured impulsivity and hyperactivity were significantly higher in patients with DLB, compared with both the Alzheimer’s disease and healthy control groups, they noted.

The investigators suggested that the association between ADHD symptoms and DLB may be explained by a common neurotransmitter pathway dysfunction. "In ADHD there are low levels of tonic [dopamine], and the abnormalities in [noradrenaline] may affect the maturation of central dopaminergic systems," they wrote. "This may be a risk factor for the development of DLB as well as Parkinson’s disease."

Although it is possible that both diseases may lie on a continuum of a single disease beginning with ADHD manifested in childhood and continuing into adulthood as DLB "when neuronal loss and gliosis in the substantia nigra, locus coeruleus, and nucleus basalis of Meynert occur," the authors doubted that this hypothesis could be true, because low dopamine levels in ADHD are not initially associated with Parkinsonlike or DLB symptoms.

The study findings may be limited by several factors, including the possibility that ADHD may occur more frequently in individuals with a personality type that could be linked to DLB or that "ADHD exposure could be a reflection of DLB not yet recognized," the authors stated.

The authors disclosed having no relevant financial conflicts.

Adults with symptoms of attention-deficit/hyperactivity disorder may be at increased risk for developing dementia with Lewy bodies as they age, according to a case-control study published in the European Journal of Neurology.

Patients who developed dementia with Lewy bodies (DLB) in older age had a history of ADHD symptoms in adulthood at more than three times the rate of healthy older adults or patients with Alzheimer’s disease, reported Dr. Angel Golimstok and colleagues at the Hospital Italiano Buenos Aires (Argentina).

The study is the first to establish a clear link between adult ADHD symptoms and DLB.

To investigate the possibility that ADHD symptoms may precede DLB, the researchers recruited a representative sample of patients with dementia and healthy controls from the membership of a large prepaid health maintenance organization model during 2000-2005. Two neurologists blinded to the purpose of the study used the DSM-IV and the Wender Utah Rating Scale to assess retrospective reports from family members or close friends about the patients’ previous symptoms of ADHD (Eur. J. Neurol. 2011;18:78-84).

Dr. Golimstok and associates determined that 52 (48%) of 109 patients with DLB had previously suffered from symptoms of adult ADHD, compared with 38 (15%) of 251 patients with Alzheimer’s disease (odds ratio 5.1) and 23 (15%) of 149 healthy control patients (OR 4.9). This meant that DLB patients were about five times more likely to have had ADHD symptoms than were Alzheimer’s disease patients or healthy controls.

Scores on parts of the rating scale that measured impulsivity and hyperactivity were significantly higher in patients with DLB, compared with both the Alzheimer’s disease and healthy control groups, they noted.

The investigators suggested that the association between ADHD symptoms and DLB may be explained by a common neurotransmitter pathway dysfunction. "In ADHD there are low levels of tonic [dopamine], and the abnormalities in [noradrenaline] may affect the maturation of central dopaminergic systems," they wrote. "This may be a risk factor for the development of DLB as well as Parkinson’s disease."

Although it is possible that both diseases may lie on a continuum of a single disease beginning with ADHD manifested in childhood and continuing into adulthood as DLB "when neuronal loss and gliosis in the substantia nigra, locus coeruleus, and nucleus basalis of Meynert occur," the authors doubted that this hypothesis could be true, because low dopamine levels in ADHD are not initially associated with Parkinsonlike or DLB symptoms.

The study findings may be limited by several factors, including the possibility that ADHD may occur more frequently in individuals with a personality type that could be linked to DLB or that "ADHD exposure could be a reflection of DLB not yet recognized," the authors stated.

The authors disclosed having no relevant financial conflicts.