Table 1 provides an overview of the participants' characteristics, experimental designs, and main findings of studies that investigated the efficacy of CBT in the treatment of psychiatric disorders in PD. A randomized, controlled clinical trial (RCT) compared the efficacy of individually administered CBT with that of clinical monitoring alone (i.e., with no new treatment) for depression in 80 PD patients, as measured by changes in the Hamilton Depression Rating Scale (HAM-D) score. CBT-treated patients received 10 weekly individualized sessions (60–75 minutes), whereas the control arm participants maintained stable medical regimens with no new interventions. The results revealed a significant improvement in both standardized depression and anxiety measures in the CBT group (the mean HAM-D score at the end of the study was 13.6 in the CBT group and 19.3 in the clinical-monitoring-alone group, whereas the mean Beck Depression Inventory [BDI] score was 9.7 in the CBT group and 17.4 in the clinical-monitoring-alone group). Secondary outcomes were anxiety, negative thoughts, sleep, quality of life, coping, social support, caregiver burden, and PD symptoms. Quality of life and social support were measured by the social functioning, physical role limitations, and physical disability subscales of the Medical Outcomes Study Short-Form Health Survey and by the Social Feedback Questionnaire. No significant group-by-time improvements were noted for secondary outcomes, including social support; however, significant changes from baseline were observed at the Medical Outcomes Study Short-Form Health Survey. Specific modifications from standard CBT include a greater emphasis on behavioral and anxiety management, as well as inclusion of a supplemental caregiver educational program. Individual sessions incorporated exercise, behavioral activation, thought monitoring and restructuring, relaxation training, worry control, and sleep hygiene. The CBT group displayed greater improvements in quality of life, coping, and anxiety, as well as a lower degree of motor decline. The improvement persisted at the 1-month follow-up. In an open treatment study on 8 depressed PD patients, 12 weekly individual CBT sessions (50 minutes) improved depression, as measured by HAM-D scores, after the intervention, with 4 patients meeting remission criteria for depression (defined as HAM-D ≤7). The CBT session was highly structured and included setting agenda, mood check, bridge from last session, today's agenda items, homework assignment, summary of session, and feedback from patient. CBT performed in 15 PD patients led to a significant improvement in depression measures and negative cognitions, and an increased perception of social support over the course of treatment, as well as to a mild, though not significant, improvement in anxiety; mood improvement was sustained at the 1-month follow-up. Patients' caregivers attended three to four psychoeducational sessions, which were held separately from patients' treatment sessions and focused on strategies for offering appropriate support and ways to respond to patients' negative thoughts in a targeted manner. The CBT sessions involved training in stress management, behavioral changes, sleep hygiene, relaxation techniques, and cognitive restructuring. Other studies have assessed the efficacy of CBT therapy in depression in small samples of PD patients.[25-27] Two studies have evaluated the efficacy of group CBT for psychiatric symptoms in PD.[28, 29] Group CBT proved useful in a waitlist-controlled trial conducted on 18 PD patients. PD patients were included if they were diagnosed with at least one depressive and/or anxiety disorder according to DSM-IV criteria. Secondary outcomes were quality of life and depressive and anxious cognitions. The CBT techniques include psychoeducation, relaxation training, cognitive therapy, problem solving, and behavioral activation. A number of PD-specific adaptations were implemented. Group CBT patients displayed a significant improvement in depressive symptoms (mean reduction in depression of 3.91 compared with an increase of 0.29 for waitlist participants; P = 0.011), though not in anxiety symptoms (mean reduction in anxiety of 3.64 compared with 0.43 for waitlist participants; P = 0.25). Group treatment for individuals with PD affords several therapeutic advantages; as functional impairment worsens, individuals with chronic neurological diseases tend to experience increased stigma, withdrawal, and social isolation, which play a significant role in both the development and persistence of psychiatric comorbidity. The researchers of one open-label study showed that group CBT was useful in the treatment of depression and anxiety. The improvement in psychiatric symptoms was accompanied by a reduction in motor symptoms and an improvement in quality of life, assessed with the Parkinson's Disease Quality of Life Questionnaire. The group CBT administered to the patients consisted of standard group CBT that was focused on the link between psychological distress and physical illness. Some sessions were aimed at understanding patients' vulnerability and their fear of the future; specific PD sessions were also held and included describing and sharing emotions after the diagnosis of PD, observation of mood changes, acceptance and evaluation of disease severity, and personal beliefs regarding the neurological disease, analysis of the content of thought and emotions related to the underlying disease, and the consequences of behavior (using the classic scheme of self-observation).
The effect of telephone-based CBT for depression in PD was investigated in 21 PD patients who met the DSM-IV criteria for primary major depressive disorder, dysthymia, or a not otherwise specified depressive disorder. All participants received 10 sessions of individually administered telephone-based CBT along with four separate caregiver-administered educational sessions. Telephone sessions incorporated behavioral activation, recommendations to gradually increase exercise, relaxation training, worry control, sleep hygiene, and anxiety management techniques. Telephone-based CBT was associated with significant improvements in the HAM-D 17; secondary endpoints included severity of depression and treatment response, anxiety, negative thoughts, quality of life, social functioning, physical role limitations, coping, social support, sleep, and caregiver burden. No significant effects were found on measures of quality of life assessed with the quality-of-life subscales (social functioning, physical role limitations, and physical disability) of the Medical Outcomes Short Form. The results were comparable to the additional in-person CBT pilot studies for PD, thereby demonstrating that the beneficial effects of telephone psychotherapy observed in other chronic medical conditions are not attenuated in PD. In another telephone-administered CBT study on the treatment of depression in PD, patients were randomized to either a “CBT arm” or a “support arm.” Specific interventions included depression and anxiety education, relaxation training, cognitive therapy, problem solving, activity scheduling, exposure, and sleep-management skills. CBT arm patients displayed a mild improvement in depression and a significant improvement in anxiety both post-treatment and at the 1-month mark, whereas the support arm patients did not. Quality-of life dimensions related to PD was assessed using the 39-item PD questionnaire (PDQ-39). The effect size was small for the post-treatment time point, with no differences between CBT- and support-treated patients.
CBT has also been used in PD for treatment of other psychiatric disorders. An RCT based on 12 weekly CBT sessions compared the efficacy of a CBT-based intervention with that of a control condition, both combined with standard medical care, for the management of ICD in 45 PD patients. The researchers used standard treatments of ICD in the general population adapted for PD, with additional components on communication and interpersonal relationships, executive dysfunction, and elements of case management. CBT plus standard medical care was found to be more effective than standard medical care alone in reducing severity of ICD in PD patients, as measured by the Clinical Global Impression (CGI) Assessment; in addition, the CBT-based intervention improved depression and anxiety. A study on 22 PD patients with insomnia demonstrated that CBT facilitates improvement of sleep disorders. CBT sessions include sleeping diary, reviewing participants' problems and expectations, and cognitive reconstruction; the main aim was to improve sleep by reducing unnecessary worrying. In another controlled study, CBT was compared with doxepin and placebo for treatment of insomnia in PD patients. CBT treatment reduced the Insomnia Severity Index (ISI; −7.8 ± 3.8 vs. −2.0 ± 3.9; P = 0.03) as well as the examiner-reported clinical global impression of change (P = 0.006).