A form of cognitive-behavioral therapy (CBT) designed to target impulse behaviors, such as pathological gambling and compulsive shopping, is proving to be effective in patients with Parkinson's disease (PD).
New research shows that three quarters of those receiving the treatment had improved symptom severity compared with only about a third of those who were not given the therapy.
However, the intervention did not significantly improve caregiver burden according to some measures.
"The study showed that the intervention was effective," study author Anthony S. David, MD, a neuropsychiatrist at the Institute of Psychiatry, King's College, London, United Kingdom, told Medscape Medical News.
"It certainly improved patients' general levels of functioning, it reduced the number of them meeting a cutoff for having problematic impulse control behaviors, and it was helpful a little bit for their carers as well."
CBT is typically used solely to treat depression and anxiety in patients with PD. This was the first study to suggest that CBT might be useful for impulse control in PD, said Dr. David. The results are encouraging and warrant a larger multicenter trial, he said.
The study was published in the February 26 issue of Neurology.
Surveys show that about 15% of patients with PD exhibit impulse control behaviors. "It's a hidden problem," says Dr. David, adding that doctors don't always recognize it. Younger male patients who have had mental health problems in the past are more at risk. Newer dopamine agonist medications are most likely to spur the behaviors, he said.
Currently, the only treatment approach is to reduce such antiparkinson medication; however, this runs the risk of worsening the parkinsonian symptoms, said Dr. David. "It's a real problem; either you have people who are undertreated for their parkinsonism or they're well treated but they're sort of getting into all sorts of debt problems and family problems."
Amantadine, a second- or third-line anti-PD drug, which some had labeled a "miracle cure" for impulse control problems, does not appear to be living up to the original hype, said Dr. David.
The current pilot study included 45 patients diagnosed with idiopathic PD according to the UK Parkinson's Disease Society Brain Bank criteria, and with associated impulse control behaviors (ICB) that had failed to remit despite standard measures, including medication changes.
Reward- or incentive-based ICBs involve repetitive and compulsive acts despite potentially harmful financial, legal, psychological, and social consequences. In addition to pathological gambling and compulsive shopping, such behaviors can include hypersexuality, compulsive eating, and obsessive hobbying.
In this study, patients were randomly assigned to a 6-month wait list for CBT along with standard medical care (n = 17) or to CBT starting immediately (n = 28).
The therapy, adapted for patients with PD, involved 12 weekly sessions, often taking place in the patients' own home. CBT involves behavior monitoring, concentrating on pleasant thoughts, problem-solving (eg, reducing gambling by canceling credit cards, avoiding driving by gambling establishments, and removing Internet gambling sites), training in relaxation, and identifying and challenging negative behaviors.
Most of the study participants were young men who had had more than 3 ICBs for several years. The 2 groups were similar in terms of demographic and clinical characteristics. There were also no significant differences in the use of dopamine agonists.
In the treatment group, 58% of patients completed all 12 sessions, and 88% completed at least 6 sessions.
At 6 months, the study uncovered a significant improvement in symptom severity as measured by the clinician-rated Clinical Global Impression (CGI) in the treatment group compared with controls, from a mean score consistent with moderate to one of mild illness-related symptoms (4.0 to 2.5 vs 3.7 to 3.5 in the control group). There was also a significant (P < .001) benefit when CGI improvement categories were compared. The authors pointed out that 75% of the treatment group improved compared with 29% for the wait-list group.
The researchers also found that the neuropsychiatric disturbances as seen on the Neuropsychiatric Inventory (NPI) improved significantly compared with controls (mean, 26.0 to 16.4 vs 22.0 to 23.8; P = .03).
Levels of depression and anxiety also improved. A total of 8% scored above the clinical threshold for depression (ie, moderate to severe; score of 19 or more) on the Beck Depression Inventory in the treatment group compared with 41% in the wait-list group. And 29% scored above the clinical threshold for anxiety (16 or more) on the Beck Anxiety Inventory in the treatment group vs 59% in the control group.
Twenty-three caregivers for patients receiving treatment and 13 caring for patients on the wait list were included in the analysis. Most of these carers were spouses or children of the patients.
The analysis did not find a significant benefit in terms of caregiver burden in the treatment group according to the Zarit burden interview (P = .75) or in the total distress score on the NPI (P = .12).
This finding was "slightly disappointing," although it could be explained by a timeline that wasn't long enough, said Dr. David. "A burden might take a long time to sort of wear off. Maybe it takes a while before the carer really notices that their loved one isn't such a burden anymore."
Roseanne D. Dobkin, PhD, associate professor, psychiatry, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway, who has extensively researched CBT in patients with PD, agreed that the effect on caregiver burden might take longer to manifest.
"It's been my experience that caregiver burden is a really hard construct to modify. We have looked at it as a secondary outcome in a controlled trial of CBT for depression in PD, and found really good effects on other measures but not burden. Perhaps we need to develop more stand-alone, primary interventions for caregiver burden."
In the current study, the Golombok Rust Inventory of Marital State (GRIMS) showed no effect of the treatment on caregivers' perception of their relationship with their partner. However, scores on the General Health Questionnaire (GHQ)-28 were significantly better among those caring for patients receiving treatment, indicating reduced levels of anxiety and depression.
Dr. David agreed that it's "not a perfect study" because it was limited by a small sample size, short duration, inability to predict individual response, and an unblinded design, although he said it's impossible to carry out such a study blinded. But he stressed that the ratings were done "according to really strict manuals and protocols" to reduce the effect of bias (raters were not independent of the study).
Addressing the potential problem of accessing the therapy, Dr. David said it could be made more widely available by training clinical psychologists or nurses specializing in treating patients with PD.
Although controlling impulse behaviors could mean important savings to the healthcare system, cost-effectiveness of this CBT intervention needs to be assessed in a larger trial, said Dr. David.
Such a trial, if it continued for long enough, might show that the therapy teaches patients skills that they can keep drawing on. "These cognitive therapies are usually quite good at having a longer-term effect, unlike say a drug," said Dr. David. "If you put someone on a medication, as soon as they stop that medication, they're back to square one."
In an accompanying editorial, Graeme J.A. Macphee, FRCP, Movement Disorders Clinic and Medicine for the Elderly, Southern General Hospital, Glasgow, and Alan Carson, MD, Department of Rehabilitation, Department of Clinical Neurosciences and University of Edinburgh, Scotland, said the findings for such an "original" intervention are "potentially important," especially because there is limited evidence for other therapies, such as serotonin reuptake inhibitor antidepressants, acetylcholinesterase inhibitors, anticonvulsants, and deep brain stimulation surgery.
They added that the intervention was "pragmatic and complex," incorporating practical approaches as well as specialist nurse support and education. "Encouraging patients and caregivers to 'distract' in pleasurable day-to-day activity, while reducing ICB opportunities, may be an effective, inexpensive intervention."
The commentators cited some of the study's limitations, including no formal recording of measures of executive function and no data collected on the prevalent ICG source population. Because most of the study group consisted of younger men with PD, generalizability to other demographic groups may be uncertain, they said.
"Despite these limitations, the study demonstrates proof of concept that psychological-based therapies may be of value in ICB in PD," they write.
Dr. Dobkin called the results exciting, novel, and an "important first step" that is "very encouraging."
She said CBT in general has been "greatly underutilized and underresearched" in PD. "Fortunately, we're really at a point now where we're seeing an increase in the application of cognitive-behavioral techniques to address a wide range of nonmotor complications like impulse control behaviors that present in the PD population."
Access to the therapy may be an issue for patients with PD, who may have mobility problems, said Dr. Dobkin. Therapy is most effective when it's initially delivered on a weekly basis for 3 to 4 months, followed by maintenance appointments that may be spread over a longer period, she said.
It's important that the therapist be knowledgeable not only about CBT but also about PD, she said. "The way in which you approach the treatment and apply the techniques is going to vary greatly if a person has PD versus not. For example, a main intervention is helping the patient to identify and to challenge or restructure their negative thoughts and for a clinician who is not well versed about PD and about medications used to treat it, it could be very difficult to help a patient identify thoughts that for them are negative — and untrue — and possibly replace those thoughts with more realistic, balanced beliefs."
She added that the current pool of providers who are knowledgeable about both CBT and PD is limited.
Also critical is getting patients involved in more meaningful activities, and it takes a sophisticated knowledge of PD to do that effectively, said Dr. Dobkin. "Sometimes patients stop doing things because they overestimate their disability, especially if they're newly diagnosed, but if you're not familiar with PD, you might not recognize that a patient is doing that."
Familiarity with the condition also makes it easier to modify activities to the unique needs of a patient with PD, she said.
Dr. David has received travel expenses and honoraria for speaking and educational activities from Janssen-Cilag; serves on advisory boards for Eli Lilly, UCB, and Novartis; is coeditor of CognitiveNeuropsychiatry, and receives research funding from NIHR UK and the Medical Research Council (UK). Dr. Dobkin has disclosed no relevant financial relationships (she does do have a National Institutes of Health (National Institute of Neurological Disorders and Stroke) grant and a foundation grant (Patterson Trust Awards Program in Clinical Research) related to treating depression in PD with CBT). Dr. Macphee and Dr. Carson have disclosed no relevant financial relationships.
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Cite this: Cognitive Therapy Controls Impulse Behaviors in Parkinson's - Medscape - Feb 26, 2013.