Pharmacological interventions for anxiety in Parkinson's disease sufferers

Anxiety disorders are a common non-motor symptom of Parkinson's disease (PD) with a reported prevalence ranging from 20% to 50%. Although anxiety is associated with Parkinson's disease, anxiety disorders can begin before the onset of motor symptoms, and have been linked to a possible abnormality of dopaminergic, serotonergic, and adrenergic neurons that precedes motor disturbance.

Several studies have reported the pharmacological treatment of depression in PD, but none have been randomized clinical trials with a primary outcome measure of anxiety. Two trials showed that pharmacological intervention with tricyclic antidepressants or selective serotonin reuptake inhibitors proved beneficial in treating anxiety in PD. However, the effect size was modest. Anxiety is associated with off-periods and improved by L-Dopa, especially in patients with high levels of anxiety.

Decreasing off-periods is important for managing anxiety in patients with motor fluctuations. Minor suggestive data indicate that tricyclic antidepressants and selective serotonin reuptake inhibitors can be helpful with modest effect sizes, but the former can cause additional side effects. Only one study has examined the use of benzodiazepines to treat anxiety in PD, and benzodiazepines cannot be recommended because they increase the risk of falling. Further clinical studies for pharmacological intervention against anxiety are required.