Use of the GDS-15 geriatric depression scale as a screening instrument for depressive symptomatology in patients with Parkinson's disease and their carers in the community

Objectives: to assess the level of depressive symptomatology in a community based group of patients with Parkinson's disease (PD) and their carers and to investigate the patient characteristics that might predict carer distress. Methods: the GDS-15 geriatric depression scale was used to measure self-rated depressive symptoms in a group of 132 subjects with clinically probable PD randomly selected from a community-based disease register. Disease severity was assessed by the Webster scale and cognitive function by the CAMCOG test. Carers of the patients, who in this study were all spouses, were also asked to complete the GDS-15. Results: a total of 64% of our group of patients and 34% of carers scored within the 'depressed' range on the GDS-15. Patients with high levels of depressive symptoms tended to have more severe disease, disease of longer duration and more impaired cognitive function. The GDS score of the carer was best predicted by the GDS score of the patient being cared for. Less than 10% of patients and carers were being treated with antidepressant medication. Conclusions: this community-based study confirms the high level of depressive symptoms in PD suggested by hospital- and clinic-based studies. Depression in patients appears to be related to disease severity and cognitive impairment. An important determinant of carer distress and mood disorder, as reflected by the GDS score, appears to be the level of depression expressed by the patient being cared for. Despite high levels of depressive symptoms in both patients and carers, very few subjects were in receipt of antidepressant drug therapy.