Elana J Forbes, Gerard J Byrne
Anxiety is a major non-motor complication of Parkinson’s disease (PD). However, a high proportion of PD patients experience Anxiety not otherwise specified (NOS), being clinically significant anxiety that does not meet Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria for a diagnosable anxiety disorder. As such, anxiety in PD is under-recognised and its diagnosis is under-developed. Thus, we aimed to identify the demographic, psychiatric, clinical and cognitive characteristics associated with Anxiety NOS in PD. A cross-sectional design was employed using a convenience sample of 184 nondemented PD patients recruited from neurology outpatient clinics. A semi-structured interview was used to categorise participants into three groups: PD patients with DSM-IV anxiety disorders, Anxiety NOS or no anxiety. Logistic regression models were constructed to identify characteristics associated with Anxiety NOS. Associations were found between Anxiety NOS and female gender, poorer quality of life, depression, global neuropsychiatric impairment, complications of PD therapy, the presence of dyskinesias, greater time spent with dyskinesias, greater time in the “off” state and persistent, episodic and social anxiety. Anxiety NOS demonstrated more severe therapy complications, greater global cognitive impairment and higher levodopa doses than DSM-IV anxiety. These findings present evidence that Anxiety NOS in PD is a distinct, fluctuations-based, PD-specific anxiety subtype. These identified characteristics of Anxiety NOS in PD could facilitate increased recognition and treatment of anxiety inPD.