Table 3.

Summary of Findings by Psychosocial and Clinical Factors

Author	Study Design, Country	Subjects	Strength of Association
LATERALITY OF MOTOR SYMPTOMS
Nuti et al (2004)	Quantitative case control study Italy	Outpatients of the Movement Disorders Unit	No correlation was found between laterality of motor signs and the prevalence of mood and anxiety disorders
Foster et al (2011)	Case control study USA	Patients of the Movement Disorders Center	Patients of the Movement Disorders Center
CLINICAL FEATURES
Nuti et al (2004)	Quantitative case control study Italy	Outpatients of the Movement Disorders Unit	No correlation was found between PD clinical features (akinetic rigid vs. tremor dominant) and the prevalence of mood and anxiety disorders
Henderson et al (1992)	Empirical study with self report questionnaire USA	Community –dwelling older adults	Motor fluctuations associated with increase likelihood of depression and anxiety self report Association found between motor state and depression and anxiety disorders (r= 0.56, p<0.001)
SEVERITY OF PD
Nuti et al (2004)	Quantitative case control study Italy	Outpatients of the Movement Disorders Unit	No correlation was found between the severity of the disease and the prevalence of mood and anxiety disorders
Menza et al (1993)	Case control study USA	Outpatients of the Movement Disorders Clinic	Significant correlations were found between RDRS-2 and GDS (r= 0.48, p<0.01), Zung (r= 0.59, p<0.001), and SAS (r= 0.50, p<0.001) Correlation found between H/Y and SAS (r= 0.36, p<0.05), GDS (r= 0.41, p<0.01), and Zung (r= 0.39, p<0.01)
Henderson et al (1992)	Empirical study with self report questionnaire USA	Community –dwelling older adults	Association found between frequency of symptoms and depression and anxiety disorders (r= 0.66, p<0.0001)
PD ONSET
Nuti et al (2004)	Quantitative case control study Italy	Outpatients of the Movement Disorders Unit	No correlation was found between age of PD onset and the prevalence of mood and anxiety disorders
Henderson et al (1992)	Empirical study with self report questionnaire USA	Community –dwelling older adults	Association found between PD onset and depression and anxiety disorders (r= 0.74, p<0.001)
PD DURATION
Nuti et al (2004)	Quantitative case control study Italy	Outpatients of the Movement Disorders Unit	No correlation was found between disease duration and the prevalence of mood and anxiety disorders
Foster et al (2011)	Case control study USA	Patients of the Movement Disorders Center	Significant positive correlations between PD duration and severity of depressive and anxiety symptoms [GDS (r=0.496, p=0.002), BDI-II (r=0.439, p=0.006) and the STAIS (r=0.417, p=0.009)] among RHO patients
ANTIPARKINSON THERAPY
Nuti et al (2004)	Quantitative case control study Italy	Outpatients of the Movement Disorders Unit	No correlation was found between PD pharmacological therapy and the prevalence of mood and anxiety disorders
Menza et al (1993)	Case control study USA	Outpatients of the Movement Disorders Clinic	No significant association was found between anti- Parkinson medications and depression and anxiety disorders
AUTONOMIC SYMPTOMS
Berrios et al (1995)	Prospective case control study Great Britain	Subjects from the University of Cambridge Department of Psychiatry Parkinson’s Disease Project Database	Significant correlations were found between autonomic symptoms and depression (HRSD, P<0.01) and anxiety disorders (HRSA, P<0.01)

Note. BDI-II= Beck Depression Inventory-II; GDS= Geriatric depression scale; HRSA= Hamilton Rating Scales for Anxiety; HRSD= Hamilton Rating Scales for Depression; H/Y staging= Hoehn and Yahr staging system; LHO= left hemibody onset of symptoms; RDRS-2=Rapid Disability Rating Scale-2; RHO= right hemibody onset of symptoms; SAS= Zung Self-Administered Anxiety Questionnaire; STAI or STAIS= State-Trait Anxiety Inventory State; Zung= Zung Depression Questionnaire