| Primary Progressive Aphasia (PPA) is a dementia syndrome characterized by a gradual impairment of language functioning while other cognitive domains remain intact for at least two years following symptom onset. Given that PPA patients suffer progressive interference with communication despite preserved memory, reasoning, and insight, there is reason to believe they may experience depression, although few studies have examined this. This thesis is comprised of two studies based on research documenting that patients with post-stroke aphasia are known to experience depression, which is correlated with fluency of speech and insight into symptoms. Study 1 used a non-verbal measure, caregiver report, and a novel questionnaire to evaluate depression experienced by PPA patients. Results showed that 29% of PPA patients scored in the depressed range and a substantial proportion reported symptoms in the "sub-clinical range". A novel questionnaire showed that PPA patients reported increased frustration and worry associated with their language impairment. A non-verbal measure and caregiver reports were not useful in detecting depression in PPA patients. Study 2 investigated the relationships between speech fluency, awareness of language deficits, and depressive symptoms in PPA. To address this issue, fluency in PPA was measured by reporting performance on specific measurements of fluency, rather than classifying patients dichotomously. Results showed no relationship between fluency or insight and depression in PPA patients. In conclusion, the assessment of depression remains challenging in PPA patients; visual scales and caregiver report are not reliable. PPA appears to affect patients' mood, but the level of impact generally falls in the sub-clinical range of mood disorder. Depression in PPA is not related to disease factors such as speech fluency and insight. Recommendations for the assessment of depression in progressive aphasia are discussed as are the potential etiologies of depression in this population. |
