Methods A sample of saliva was collected from 107 Prostate Cancer (PCa) patients 45 min after waking in the morning (i.e., at the apex of the diurnal variation). Patients also completed the PHQ9 9, a brief and validated self-report scale for measuring Major Depressive Disorder, on the same day. Background data regarding cancer status and treatment were also collected. Cortisol assay procedures were commensurate with those in the current and past literature.Results Patients were aged between 52 and 82 years (M = 68.4yr, SD = 6.2yr), had received their diagnosis an average of 19.7 months prior (range = 2 to 83mo). Most (85.7%) lived with their wife or partner, with 8.8% divorced, 2.2% widowed and 3.3% never married. Most (70.3%) were experiencing their first bout of PCa, with 28.6% suffering from recurring PCa and 1.1% in remission. Past treatments included radiation therapy (0.9%), surgery (41.8%), hormone therapy (14.5%), combinations of these treatments (2.7%), no treatment (1.8%), and watchful waiting (38.3%). Current treatments were: radiation therapy (73.2%) awaiting surgery (0.8%), hormone therapy (0.0%), combinations of these (23.5%), no treatment (0.8%), and watchful waiting (1.7%). PHQ9 scores ranged from 10 to 23 (M = 12.6, SD = 2.6). The authors of the PHQ9 described scores of 10 to 14 as “moderate, requiring a treatment plan”, 15 -19 as “moderately severe, requiring immediate” treatment, and 20-27 as “severe”, also requiring immediate treatment.