Objectives. Parkinson's disease (PD) is a neurodegenerative disorder, affecting the motor system with psychological difficulties also frequently reported. While explanations for psychological difficulties are historically situated within a biomedical framework, more recently the relevance of psychological determinants has become a research focus. This review therefore examines this relationship with the two most commonly reported psychological difficulties (anxiety and depression) in people with PD.Methods. Databases were systematically searched up to 17 December 2013, identifying twenty-four studies meeting inclusion criteria.Results. Significant predictors of heightened anxiety and depression included: increased emotion-focused coping; less problem-focused coping; lower perceived control; more dominant beliefs about PD as part of a person's identity, and influence on life; less social support and more avoidant personality types.
Conclusions.Relationships between some specific psychological predictors and depression and anxiety seem well supported. The complexity of relationships between these psychological determinants should be taken into consideration when delivering psychological interventions.
ANXIETY AND DEPRESSION IN PARKINSON'S DISEASE 2
Psychological predictors of anxiety and depression in Parkinson's disease:
A systematic reviewParkinson's disease (PD) is a chronic neurodegenerative disease typically characterized by manifestations of motor control problems such as tremor, muscular rigidity and bradykinesia (Jankovic, 2008;Stern, 1988). Although less reported, non-motor difficulties such as impulse control, sleep, anxiety and depression are common within the population (Chaudhuri, Healy, & Schapira, 2006). It is accepted that people with PD typically present with higher levels of depression than age-matched controls (Reijnders, Ehrt, & Weber, 2008). Moreover, despite being less frequently presented (or, at least, measured), anxiety is also a common problem, with a far greater prevalence than in the general population (Dissanayaka et al., 2010;Pontone, Williams, Bassett, & Marsh, 2006). Such high levels of distress are concerning in their own right but also because of their importance in determining health-related quality of life more generally A wider understanding of the range (and relative frequency) of psychological determinants of (and their intra-structural relationship to) anxiety and depression would enable interventions to be formulation-based after an informed assessment process (Simpson et al., 2013b). Consequently, the current systematic review, using the robust search methodology Where papers reported group comparisons, studies were included if they reported factors separately for the PD group. Studies could be included if they reported a prospective design, although cross-sectional studies were also eligible to be included. Studies reporting outcomes of interventions such as brain surgery (e.g., Berney et al., 2002) and CBT (e.g., Dobkin et al., 2011) on depression and anxiety ...