Ask an Expert: Dr. Andrew Howard Discusses When Parkinson's Disease and Bipolar Disorder Occur Together
Dr. Andrew Howard currently serves as educational coordinator of the training component of the British Columbia Neuropsychiatry Program, one of two accredited Neuropsychiatry fellowship programs in Canada. He is the Associate Program Director of the psychiatry residency program at UBC, organizing and overseeing the academic curriculum.
As Clinical Professor in the Department of Psychiatry at the University of British Columbia, his current interests include: optimal assessment and management of patients with somatic symptom disorders and functional neurological disorders; intensive rehabilitation of individuals with neurological conditions with psychiatric symptoms (including traumatic brain injury and movement disorders); clinical research in deep brain stimulation of refractory depression and movement disorders, functional cognitive disorders after mild traumatic brain injury and head injury, and pharmacotherapy of anxiety in Parkinson’s. He acts as the consultant psychiatrist and clinical researcher to movement disorder patients at the University of British Columbia at the Centre for Huntington Disease and the Pacific Parkinson’s Research Centre.
Dr. Andrew Howard studied psychology during an undergraduate degree at Harvard University, with a specific interest in neurophysiology, and medicine at Queen’s University with specific interest in psychosomatic medicine. Since that time, he returned to Vancouver to complete a residency in psychiatry and a fellowship in clinical neuropsychiatry. He is certified in Behavioural Neurology and Neuropsychiatry by the United Council of Neurologic Subspecialties.
What is a neuropsychiatrist, and how is that different from a neurologist or psychiatrist? What kinds of conditions do neuropsychiatrists treat?
No one seems to know what a neuropsychiatrist does, as it is a pretty niche subspecialty. Most of us started as psychiatrists, but some as neurologists, and then the vast majority of us did extra training after our specialty training in one of those parent specialties.
Psychiatrists that liaise with other specialists mostly (and are mostly hospital or hospital clinic based) are referred to as consultation-liaison psychiatrists. From that group, specialists who are interested in consultation to neurologists more than other specialists are referred to as neuropsychiatrists. Some have done extensive subspecialty training in neurological/psychiatric skills (assessment and treatment methods), and others have not. Some are extensively involved in treating dementias, as this is one of the most common (especially now) neurological conditions.
Most of us see all neurological conditions that manifest with psychiatric symptoms (e.g. psychotic symptoms developing in the context of cognitive decline in Parkinson’s disease). Many of us also assess and treat patients with neurological-type symptoms (pain, headache, vertigo, movement/walking difficulties) that are a manifestation of psychiatric conditions (psychosomatic conditions). Finally, some of us have subspecialized and treat only certain neurological conditions (e.g. MS, Parkinson’s, Tourette’s).
The vast majority of referrals come from neurologists or psychiatrists for patients who have seen both sets of specialists and concerns/questions still remain.
What symptoms or challenges might signal that someone with Parkinson’s disease (PD) should see a neuropsychiatrist?
Ideally, for psychiatric symptoms or psychosocial issues which are beyond the grasp of the family physician, social worker, neurologist, geriatrician, or other clinician, a general psychiatrist or geriatric psychiatrist (if the patient were older than 75, for example) would assess the patient. If there were concerns about the etiology of the symptoms or psychosocial issues, or any issues/questions with regards to management, this would be a perfectly suitable reason to consult the neuropsychiatrist.
An example might be suitability for surgical candidacy from a psychiatric point of view for deep brain stimulation (how reliable is the patient in terms of mental/emotional stability, and how advanced is their disease from a cognitive-intellectual point of view). The nuances of this might be too complex for the time a neurologist or general psychiatrist has to spend with the individual.
Another example might be anxiety and depression earlier on in the disease that is not responding to standard therapies (e.g. counselling, cognitive-behavioural therapy, activation, antidepressants/anxiolytics).
Another example might be psychotic symptoms in intermediate stages of disease and whether these herald the onset of dementia or might be related to dose escalation of dopamine replacement therapies.
But the bread and butter of neuropsychiatry in all neurological conditions is executive dysfunction. It causes the most amount of grief for patients and families, aside from the grief of getting the disease. It leads to apathy, loss of emotional connectivity to people/things/activities, and disorganization, as well as problems with multi-tasking, planning, and decision-making, and inhibitory control problems with impatience, emotional lability/irritability, and impulsivity.
Because we see this and interact with patients of all backgrounds and conditions with these problems (as they are so life-changing), this probably turns out to be the most common reason you will end up seeing a neuropsychiatrist if you have Parkinson’s disease. Fortunately, many individuals with Parkinson’s, particularly those who develop the condition at an advanced age, can avoid clinically impairing executive dysfunction.
In British Columbia, how do people usually access or get referred to a neuropsychiatrist?
Our movement disorder clinics in Vancouver and Surrey have direct access to us and we are part of their clinics. If patients aren’t seeing neurologists from those clinics, and they have been reviewed by a neurologist and a psychiatrist who are invested in their long-term care, then either specialist can refer the patient to our inpatient or outpatient program. Our referral form is on our website at www.neuropsychiatry.ubc.ca.
Can Parkinson’s disease and bipolar disorder occur together, and how common is that?
This is a challenging combination, but fortunately it is quite uncommon. Just based on prevalence, there should be several dozen patients experiencing both of these conditions. I have only managed a few.
What is far more common is that symptoms of mania/hypomania/disinhibited behaviour attributable to the prodrome of Parkinson’s (in the years leading up to the motor onset) is mistaken for bipolar disorder.
In fact, the prodrome is emotionally and psychologically a very difficult time for a sizeable minority of patients (as anxiety, depression, irritability, and sleep disturbances all can precede the tremor, slowing, stiffness, and postural instability). That’s why we consistently reinforce to clinicians of all backgrounds and practice types that the onset of these symptoms later in life should raise concern for an underlying neurological condition. Our colleagues are very attuned to this.
What bipolar-related mood or behaviour changes should people with Parkinson’s and their families pay attention to?
Mania, hypomania, and disinhibited behaviour are sadly not uncommon at all in the course of Parkinson’s disease. In some samples, the rate can be as high as one in six patients developing mania/hypomania, and there is an equal incidence of impulse control problems.
One of the unique aspects of this psychiatric set of symptoms/changes is that these are reliably (but not always) attributable to an iatrogenic intervention (in other words, they are caused by our treatments for Parkinson’s rather than the Parkinson’s itself).
Executive dysfunction that is longstanding (e.g. in patients with substance abuse histories, in males, in those with history of ADHD/conduct disorder) predisposes an individual more to these changes. But far and away, a dose escalation in dopamine replacement therapy (typically a dopamine agonist) or a surgical intervention like subthalamic nucleus deep brain stimulation, in the absence of a rapid reduction in levodopa equivalent dose, can cause manic symptoms (reckless and risk-taking behaviour, impulsive decision-making, expansive mood).
Mood instability itself, in terms of periods of depression and hypomania or cycling of mood, is much more uncommon, I think. What we do see, and patients and loved ones regularly contend with, are mood changes coinciding with the end of a dose. Some individuals suffer significant dysphoria, anxiety, and even agitation as their dose is de-escalating, and some even feel mood elevation as their dose is kicking in.
When individuals are taking frequent doses of dopamine replacement (usually without the consent of caregivers and clinicians), they are often having to deal with several bouts daily of alternating moods. It can be very disabling and is part of what physicians refer to as dopamine dysregulation syndrome. These are, after all, mood-altering neurochemicals we are getting patients to take to help them move.
How can Parkinson’s symptoms and bipolar symptoms sometimes overlap or be confused with one another?
This is extremely confusing when the only place anyone can get this information from is the patient themselves. The clinician has to discern whether the symptoms of mood instability and loss of inhibitory control are related to a longstanding psychiatric mood disorder, the degenerative process, or both.
Typically, if there is a reliable collateral informant, caregiver, nurse, or clinician who knows the patient fairly well, and if the change is quite slow (over years) and progressive, it can be attributed to the disease. If it developed quite quickly (over days or weeks), it could be attributed to the treatment.
Whereas, if an individual with longstanding mood episodes (usually long periods of depression, with at least a few, or often several, hypomanic or manic episodes in the past) was continuing to experience mood changes over weeks or months, this would be more consistent with bipolar disorder.
But I have definitely seen loss of inhibitory control (impatience, irritability, impulsivity) and even apathy that was slowly progressive, and even preceded the motor onset of Parkinson’s, being referred to incorrectly as the changes of bipolar disorder.
How do doctors safely treat someone who has both Parkinson’s disease and bipolar disorder? Can you explain what makes treating these two conditions together especially challenging?
The biggest challenge in treating this comorbidity, without question, would have nothing to do with the biology of these diseases. It would be the impact that the mood disorder had already had on the individual’s psychosocial functioning by the time they developed this degenerative disease.
There is a very high likelihood of an individual with years or decades of living with bipolar disorder having an inadequate support network, financial pressures, care access limitations, concerns with compliance with care, and the inability to trust the healthcare system. From a purely medical point of view, these individuals would be highly vulnerable to mood disturbance both over days and over hours.
Medications given for mood stabilization, particularly anti-manic agents but also antidepressant augmentation agents (lithium, anticonvulsants like valproate, antipsychotics), are all capable of temporarily worsening the neurological symptoms of Parkinson’s.
Risking further mood instability by taking them off these agents, even though the intent may be optimizing their motor functioning, is extremely challenging for these individuals who are already trying to live with a degenerative disease.
Bipolar disorder is sometimes treated with medications that lower dopamine activity, while Parkinson’s disease is treated with medications that increase dopamine. How do doctors balance those opposing treatment approaches safely?
One of the biggest let-downs in drug development over the past 30 years was that there appeared to be a number of agents that promised to help control psychiatric symptoms (e.g. hypomania/mania, impulsivity, psychosis, sleep issues) without upsetting or worsening motor symptoms. They were considered to have properties far more atypical compared to the conventional dopamine-lowering antipsychotic medications.
In fact, the “third” generation of antipsychotics, mostly the dopamine modulators, are very hard to use in patients with Parkinson’s disease, almost appearing to act as agonists at lower doses (increasing impulsivity and motor output) and antagonists at higher doses (improving self-control but worsening motor symptoms).
These have all mostly disappointed mental health clinicians in the field, or have been hard to access in Canada, or are not available (e.g. pimavanserin). We still rely on quetiapine and clozapine, which are not easy for many patients to tolerate, to control bipolar disorder and symptoms suggestive of mood instability in Parkinson’s, and have relied on these two medications for decades.
I do prefer that the majority of patients use low doses of quetiapine as early as necessary in the course of their Parkinson’s for anxiety that is disabling, especially in the evening as dopamine “accumulates”, sleep disturbance that interferes with functioning, impatience/irritability/agitation particularly at end of dose or in the evening, and when psychotic symptoms first manifest (feeling of presence, illusions, passage hallucinations).
I would say the vast majority of my patients are on quetiapine at some point. At lower doses (below 150-200 mg typically), you tend not to see much interference with motor functioning, but it may not be easy to tolerate (constipation, dry mouth, dizziness, sedation).
Besides medication, what lifestyle habits or support can help people manage both conditions?
Exercise, sleep, healthy routine, social invigoration, and connection are all important interventions for both of these conditions. Anything that a person can do to avoid the dementia of Parkinson’s is advisable – so controlling blood pressure, cholesterol, blood sugar, and not smoking. All of these things are important in as far as lifestyle changes may support a person’s longevity.
However, when it comes down to it, individuals who are able to avoid the executive dysfunction and cognitive decline are the ones who live most easily with this condition (once people come to terms with having it), and sadly, I really do think a lot of this depends on chance. I have cared for many individuals who lived very healthy lives and went on to experience very early cognitive decline, dementia, behavioural disturbance, and loss of executive function.
What is the most important message you want people with Parkinson’s disease and their caregivers to understand about mental health, especially about bipolar disorder?
The earlier people get help, the better, both for patients with bipolar disorder, typically in early adulthood or adolescence, and for patients with Parkinson’s, whenever it takes effect (remember the prodrome… they may not even have motor symptoms yet).
The same stigma that has prevented people from talking to mental health clinicians for ages is still in effect. For patients with established disease, try to avoid biases in attribution (for example, “they are acting this way because of this…”). And just try to encourage them to get help.
The number of times I have seen people suffering who did not need to suffer but didn’t give themselves the opportunity to get properly assessed and treated is distressing. This is a condition which plays on the mind and the body, and can cause issues with cognitive function, and the very treatments we give to help support people in their efforts to move and not shake can play with their mind and their emotions.
People need help. Virtually everyone with Parkinson’s disease is going to experience mental and emotional challenges, directly or indirectly, as a result of the condition. And the last thing they need is an obstacle to care.