Depression in Parkinson's disease. Pharmacological characteristics and treatment

[Pharmacological treatments of Parkinson's disease]

Antiparkinsonian agents applied or under the investigation for the treatment of patients with Parkinson's disease were reviewed. Tremor, akinesia, rigidity and postual instability are key signs of Parkinson's disease. The most important one is akinesia, which includes decreased spontaneous locomotor activity, slowness of movement, awkwardness and freezing. The main pathophysiology of Parkinson's disease is neurodegeneration of nigrostriatal dopaminergic neurons. Neurotoxins or oxidative stress to the dopaminergic neurons have been discussed as one of the etiologies of degeneration. Antioxidant or neuroprotective agents will be the future drugs for Parkinson's disease. At present, supplement of dopamine by levodopa administration, retarding the metabolism of levodopa or dopamine by a dopa decarboxylase inhibitor (DCI), MAO-B (monoamine oxidase inhibitor type B) inhibitor or catechol-O-methyltransferase (COMT) inhibitor, dopamine receptor agonists, anticholinergic agents, dopamine release enhancer/uptake inhibitor, N-methyl-D-aspartate (NMDA) receptor antagonists are applied for the treatment of Parkinson's disease. New agents such as adenosine receptor antagonists, serotonergic agents and nicotinic receptor agonists are under investigation. Agents to facilitate the growth of nerves or to inhibit degeneration of nerves are also studied and will be developed for the treatment of Parkinson's disease in the future. In the case of familial Parkinson's disease, abnormal genes were identified. Gene therapy might be another future treatment for these cases.

Treatment of depression in comorbid medical illness

The rate of comorbid depression and medical illness varies from 10 to 40%. Over the years, there has been a paucity of studies completed despite the importance of knowing which antidepressants are the most effective and safest to use in comorbid states. In this review, focus is placed on disorders in these important areas: cardiovascular disease, neurological disorders, diabetes mellitus and cancer. Cardiovascular disease complications can be related in many cases to platelet clumping produced by medications; reductions in morbidity can be achieved by reducing platelet adhesiveness. Specific results have shown sertraline administration to be safe in the post myocardial infarction (MI) state. This is a time of depression-induced increases of 200-300% in mortality. Evidence for safe administration of bupropion, as well as the selective serotonin re-uptake inhibitors (SSRIs) fluoxetine and paroxetine, is also available. The appearance of major depression and diabetes mellitus has been successfully treated with fluoxetine, sertraline and nortriptyline (NTI), however, NTI may lead to a worsening of glucose indices due to its noradrenergic specificity. Regarding neurologic disorders, there is controlled data showing the safety and efficacy of citalopram, sertraline and fluoxetine in post stroke depression. Parkinson's disease has been associated frequently with depression, as might be expected from its characteristic dopamine deficient state. For perhaps the same reason, the agents that can block re-uptake of dopamine i.e., tricyclic antidepressants (TCAs), have been effective in comorborbid depression with Parkinson's disease. In dementia, there is a paucity of information on new agents. However, double-blind data seems to show efficacy for sertraline, paroxetine and citalopram. There are few studies of cancer-related depression treated in a controlled fashion with antidepressants; imipramine, amitriptyline, fluoxetine, paroxetine, mirtazapine and mianserin (not available in the USA) all have support from some published studies.

Cognitive and motor function in patients with Parkinson's disease with and without depression

The objective of this study was to define risk factors for depression in patients with idiopathic Parkinson's disease (PD) and to evaluate the correlation of depression with cognitive function and the primary domains of parkinsonian motor dysfunction tremor, bradykinesia, rigidity, gait and balance impairment. The risk factors for depression in patients with PD remain controversial. Several investigators have demonstrated a significant association between cognitive dysfunction and depression, but motoric and disease variables can confound this evaluation and have shown an inconsistent relation to depression. A consecutive series of 88 patients with PD were examined using the motor subscale of the Unified Parkinson's Disease Rating Scale (UPDRSm), Hoehn-Yahr stage (HY), and Hamilton Rating Scale for Depression (HRSD). Major depression was diagnosed according to the criteria in the Diagnostic and Statistic Manual of Mental Disorders, 4th edition. Gender, age, handedness, PD duration, side of PD onset, motor fluctuations, UPDRSm total score, daily Levodopa dose, and Mini-Mental State Examination score (MMSE) were analyzed using multivariate and univariate logistic regression, Fisher's Exact test, and Pearson correlations. Major depression was diagnosed in 12 patients (7.3%). Low MMSE score, axial bradykinesia, gait and balance impairment were strongly significant predictors of depression. In conclusion, depression and physical function are important factors impairing the quality of life for patients with PD, and regular depression screening and treatment should focus on patients with PD who have cognitive impairment, high axial bradykinesia, gait and balance impairment.

Tolerability of paroxetine in Parkinson's disease: a prospective study

Depression is a common finding in patients with Parkinson's disease (PD). Traditionally, depression has been treated with tricyclic antidepressants, which are often associated with undesirable side effects that may limit their use in PD. Few studies have been performed with selective serotonin reuptake inhibitors (SSRIs) in these patients. We assessed the tolerability of the SSRI antidepressant paroxetine (10-20 mg once per day) in 65 outpatients with PD and depression for a period of at least 3 months. Treatment was continued for 125.3+/-89.6 days (mean +/- standard deviation) in 52 patients. In these subjects the Hamilton Disease Rating Scale improved from 21.7+/-6.4 to 13.8+/-5.8 (p <0.001). Overall, 13 patients stopped paroxetine after 9.6+/-10.6 days because of adverse reactions. Two patients reported increased "off" time and tremor that reversed after treatment was stopped. No risk factors for intolerance were identified. Paroxetine is a safe and effective drug to treat depression in PD.

Motor and cognitive aspects of motor retardation in depression

BACKGROUND

Motor retardation is a common feature of major depressive disorder having potential prognostic and etiopathological significance. According to DSM-IV, depressed patients who meet criteria for psychomotor retardation, must exhibit motor slowing of sufficient severity to be observed by others. However, overt presentations of motor slowing cannot distinguish slowness due to cognitive factors from slowness due to neuromotor disturbances.

METHODS

We examined cognitive and neuromotor aspects of motor slowing in 36 depressed patients to test the hypothesis that a significant proportion of patients exhibit motor programming disturbances in addition to psychomotor impairment. A novel instrumental technique was used to assess motor programming in terms of the subject's ability to program movement velocity as a function of movement distance. A traditional psychomotor battery was combined with an instrumental measure of reaction time to assess the cognitive aspects of motor retardation.

RESULTS

The depressed patients exhibited significant impairment on the velocity scaling measure and longer reaction times compared with nondepressed controls. Approximately 40% of the patients demonstrated abnormal psychomotor function as measured by the traditional battery; whereas over 60% exhibited some form of motor slowing as measured by the instruments. Approximately 40% of the patients exhibited parkinsonian-like motor programming deficits. A five-factor model consisting of motor measures predicted diagnosis among bipolar and unipolar depressed patients with 100% accuracy.

LIMITATIONS

The ability of motor measures to discriminate bipolar from unipolar patients must be viewed with caution considering the relatively small sample size of bipolar patients.

CONCLUSIONS

These findings suggest that a subgroup of depressed patients exhibit motor retardation that is behaviorally similar to parkinsonian bradykinesia and may stem from a similar disruption within the basal ganglia.

Prevalence, clinical characteristics, and pharmacologic treatment of Parkinson's disease in residents in long-term care facilities. SAGE Study Group

Despite the high prevalence of Parkinson's disease (PD) in the elderly, little information is available regarding the epidemiology of the disease in residents in long-term care facilities. Using a population-based database with over 470,000 residents (1992-1996) of all Medicare- or Medicaid-certified nursing homes of five states, we identified 24,402 residents with a diagnosis of PD. We examined data collected with the federally mandated Minimum Data Set, and sociodemographic, clinical, and treatment information. The prevalence of PD in nursing homes was 5.2%, with peak age-specific prevalence between ages 75 and 84 years. Seventy percent of patients had moderate to severe cognitive impairment, and over 80% had moderate to severe functional disability. Less than 10% had verbal and physical signs of grief and anxiety, and 80% exhibited poor psychosocial well-being, yet only 15% were actively treated for depression. Only 44% received antiparkinsonian drugs. Female gender, black race, age, level of cognitive impairment, and level of physical functioning were inversely related to the likelihood of receiving one of these drugs. When antipsychotic drugs were administered (15%), only 1% were atypical agents. Although PD is a relatively common diagnosis among nursing home residents, pharmacologic management of these individuals appears to be less than optimal.

Neuropsychiatric aspects of Parkinson's disease

Previous studies of the neuropsychiatric aspects of Parkinson"s disease were frequently methodologically inadequate. Small sample sizes, selection bias, lack of diagnostic criteria of Parkinson"s disease, different definitions and assessment of neuropsychiatric symptoms, and lack of control groups seriously questioned the validity of and ability to generalize the results from many studies. During the past decade, however, several of these methodological issues have been addressed. Recent studies have found that mild cognitive impairment is very common, and dementia, depression, and psychotic symptoms develop in a large proportion of patients. Neuropsychiatric symptoms are important determinants of mortality and disease progression, as well as of the patients quality of life and course of disease, caregiver distress, and nursing home admission. Few adequately designed treatment trials have been published, but available evidence suggests that depression and hallucinations may be effectively treated using new antidepressants and atypical antipsychotic agents without worsening of parkinsonism.

[Reliability of the Brazilian version of the ++abbreviated form of Geriatric Depression Scale (GDS) short form]

Depression is a frequent health problem in old age, although the detection of such cases in clinical practice is often difficult. The systematic use of depression rating scales may increase diagnostic rates of depression amongst the elderly. This study aimed to assess the test-retest reliability of short versions of the Geriatric Depression Scale (GDS) with 1, 4, 10, and 15 items. Sixty-four consecutive patients aged 60 or over attending the outpatient clinic for the elderly (UNID) at the Department of Mental Health of Santa Casa of São Paulo were recruited for the study between February and May 1998. All subjects fulfilled criteria for the diagnosis of a depressive disorder (current or in remission) according to ICD-10, and had Mini Mental State scores greater than 10. They were evaluated twice in 48 to 72 hours with the GDS-15. Fifty-one patients completed both assessments. Agreement between scores for individual items was evaluated with Kappa statistic. Kappa coefficients ranged from 0.04 to 0.49, indicating that there was much variation within individual items. Total GDS-15 scores were reasonably stable, as assessed by paired Wilcoxon (z = 1.60, p = 0.109), Spearman correlation coefficient (rho = 0.86, p < 0.001), and weighted Kappa (Kappa = 0.64). The same pattern was also observed for the total scores of the GDS-10 on the paired Wilcoxon (z = 0.85, p = 0.402), Spearman correlation coefficient (rho = 0.81, p < 0.001), and weighted Kappa (Kappa = 0.60). Total score for the GDS-4 showed significant changes from test to retest (z = 3.75, p < 0.001; rho = 0.56, p < 0.001; Kappa = 0.37). These results indicate that the short GDS versions with 1 and 4 items are unreliable for use in clinical practice. In contrast, the GDS with 10 and 15 items produced consistent results in the assessment of elderly patients when total scores were used as clinical guidelines.

Clinical manifestations of Parkinson's disease

Although the clinical manifestations of PD remain similar to those described by Parkinson in the nineteenth century, knowledge of associated findings has increased dramatically. The ability to characterize the myriad of findings associated with PD enables clinicians to care better for patients with PD. Knowledge of the associated symptoms as well as the cardinal manifestations allows clinicians to target treatment to specific symptoms and thereby improve the quality of life of those affected with PD.