, according to trial results published in Neurology. The treatment’s effect on depression is “moderated by the reduction of negative thoughts,” the target of the intervention, the researchers said.
Telephone-based CBT may be a convenient option for patients, said lead study author Roseanne D. Dobkin, PhD, of the department of psychiatry at Rutgers Robert Wood Johnson Medical School in Piscataway, N.J., and the VA New Jersey Health Care System in Lyons. “A notable proportion of people with Parkinson’s [disease] do not receive the much needed mental health treatment to facilitate proactive coping with the daily challenges superimposed by their medical condition,” Dr. Dobkin said in a news release. “This study suggests that the effects of the [CBT] last long beyond when the treatment stopped and can be used alongside standard neurological care.”
An undertreated problem
Although depression affects about half of patients with Parkinson’s disease and is associated with physical and cognitive decline, it often goes overlooked and undertreated, the study authors said. Data about the efficacy and tolerability of antidepressants are mixed. CBT holds promise for reducing depression in Parkinson’s disease, prior research suggests, but patients may have limited access to in-person sessions because of physical and geographic barriers.
To assess the efficacy of telephone-based CBT for depression in Parkinson’s disease, compared with community-based treatment as usual, Dr. Dobkin and colleagues conducted a randomized controlled trial. Their study included 72 patients with Parkinson’s disease at an academic medical center. Participants had a depressive disorder, were between aged 35 and 85 years, had stable Parkinson’s disease and mental health treatment for at least 6 weeks, and had a family member or friend willing to participate in the study. The investigators excluded patients with possible dementia or marked cognitive impairment and active suicidal plans or intent.
Participants were randomly assigned to receive usual care plus telephone-based CBT or usual care only. Patients taking antidepressants were evenly divided between the groups.
Telephone-based CBT consisted of weekly 1-hour sessions for 10 weeks. During 6 months of follow-up, patients could receive one session per month if desired. The CBT “targeted negative thoughts (e.g., ‘I have no control’; ‘I am helpless’) and behaviors (e.g., avoidance, excessive worry, lack of exercise),” the investigators said. In addition, therapists trained patients’ care partners by telephone to help patients between sessions. Treatment as usual was defined by patients’ health care teams. For most participants in both groups, treatment as usual included taking antidepressant medication or receiving psychotherapy in the community.
Change in Hamilton Depression Rating Scale (HAM-D) score was the primary outcome. Secondary outcomes included whether patients considered their depression much improved and improvements in depression severity (as measured by the Beck Depression Inventory [BDI]), anxiety (as measured by the Hamilton Anxiety Rating Scale [HAM-A]), and quality of life. The researchers also assessed negative thinking using the Inference Questionnaire. Blinded raters assessed outcomes.
Sustained improvements
Thirty-seven patients were randomized to receive telephone-based CBT, and 35 were randomized to treatment as usual. Overall, 70% were taking antidepressants, and 14% continued receiving psychotherapy from community providers of their choice during the trial. Participants’ average age was 65 years, and 51% were female.
Post treatment, mean improvement in HAM-D score from baseline was 6.53 points in the telephone-based CBT group, compared with −0.27 points in the control group. “Effects at the end of treatment were maintained at 6-month follow-up,” the researchers reported.
About 40% of patients in the CBT group reported that their depression was much improved or very much improved, compared with none of the patients in the control group. Responders had mild to minimal symptomatology on the HAM-D, which indicates that the changes were clinically significant, the authors said.
Secondary outcomes also favored telephone-based CBT. “The intervention was feasible and highly acceptable, yielding an 88% retention rate over the 9-month trial,” Dr. Dobkin and colleagues said.
Compared with other control conditions, treatment-as-usual controls may enhance the effect size of an intervention, the authors noted. In addition, factors such as therapeutic relationship, time, and attention likely contribute to psychotherapy outcomes.
Success may hinge on cognitive ability
“The success of this trial highlights the need for further efficacy studies targeting neuropsychiatric manifestations of [Parkinson’s disease] and adds urgency to the discussion over policies regarding access to tele–mental health, especially for vulnerable populations with limited access to in-person mental health services,” Gregory M. Pontone, MD, and Kelly A. Mills, MD, wrote in an accompanying editorial. Dr. Pontone and Dr. Mills are affiliated with Johns Hopkins University in Baltimore.
“Only rudimentary evidence” exists to guide the treatment of depression in patients with Parkinson’s disease, the editorialists said. “Patient preference and tolerability suggest that nonpharmacologic therapies, such as CBT, are preferred as first-line treatment. Yet access to qualified CBT practitioners, especially those with a clinical knowledge of [Parkinson’s disease], is limited.”
Despite its advantages and the encouraging results, CBT may have important limitations as well, they said. Patients require a certain degree of cognitive ability to benefit from CBT, and the prevalence of dementia among patients with Parkinson’s disease is about 30%.
Nevertheless, the trial provided evidence of target engagement. “Though caveats include the single-blind design and potential confounding by time spent with patient and caregiver, the authors demonstrated that improvement was mediated by the mechanism of CBT – a reduction in negative thinking.”
The trial was funded by the Michael J. Fox Foundation for Parkinson’s Research and the Parkinson’s Alliance (Parkinson’s Unity Walk). Dr. Mills disclosed a patent pending for a system for phase-dependent cortical brain stimulation, National Institutes of Health funding, pending funding from the Michael J. Fox Foundation, and commercial research support from Global Kinetics Corporation. Dr. Pontone is a consultant for Acadia Pharmaceuticals.
SOURCE: Dobkin RD et al. Neurology. 2020 Apr 1. doi: 10.1212/WNL.0000000000009292.