Anxiety disorders are common in Parkinson's disease (PD) patients, yet are poorly studied. We examined the prevalence of anxiety disorders in PD, investigated the association between anxiety, and presentation and progression of PD, and studied for the first time the contribution of putative risk factors for anxiety in PD. A case-series of 79 PD patients recruited from neurology out-patient clinics was examined for anxiety disorders using the DSM-IV criteria. The Unified Parkinson's Disease Rating Scale and the Hoehn and Yahr Staging of PD were employed to understand the relationship between anxiety disorders, and the clinical presentation and severity of PD. A validated survey assessed putative risk factors for anxiety in PD. Twenty-five percent of PD patients were diagnosed with anxiety. Panic disorder, generalised anxiety disorder and social phobia were prevalent anxiety disorders. Comorbid depression with anxiety was observed (14%). The severity but not the duration of PD was positively related to anxiety. PD patients with postural instability and gait dysfunction symptom clustering were more likely to experience anxiety than tremor-dominant patients. While levodopa dosage had no relationship to anxiety, experience of dyskinesias or on/off fluctuations increased the risk. Lateralisation of PD had no association with anxiety. Anxiety disorders decreased with age and young onset PD patients were more likely to experience anxiety than the late onset subjects. Anxiety adds to the complexity of PD, lowering patients' quality of life. Future research can be directed to identify reactive and organic nature of anxiety in PD.

Burden is a negative psychological state induced in caregivers by the demands of providing care to a person with an illness or a disability. Managing caregiver burden in Parkinson disease (PD) is significant because informal caregivers make a substantial contribution to the well-being of persons with PD, incurring financial, social, and personal losses. Failure to recognize and manage caregiver burden may lead to burnout and premature institutionalization of the person with PD. We conducted a comprehensive literature review to identify and summarize factors that may amplify burden, including motor and nonmotor symptoms of PD, caregiver psychiatric symptoms, and caregiver coping style. We review instruments designed to sample the construct of burden among caregivers and evaluate interventions that may reduce burden, either by directly targeting caregivers or by treating PD symptoms associated with burden. We aim to provide a concise synopsis of these issues for the clinician or researcher working with this population in order to facilitate recognition of caregiver burden, provide accurate assessment, administer appropriate interventions, and stimulate further research in this area.

This systematic review confirms that anxiety, although often unrecognized, is very common and highlights the need for efficient identification of anxiety in PD. © 2016 International Parkinson and Movement Disorder Society.