%0 Journal Article
%T Apathy and Anhedonia in Parkinson's Disease
%A Yoshiaki Kaji
%A Koichi Hirata
%J ISRN Neurology
%D 2011
%R 10.5402/2011/219427
%X Depression, apathy, and anhedonia are often comorbid in patients with Parkinson's disease. Since the morbid states of apathy and anhedonia are complicated, these symptoms are often difficult to diagnose. Several therapeutic methods for apathy and anhedonia are considered effective. However, the validity of these methods has not been established. Similar to depression, apathy and anhedonia clearly affect the quality of life of patients and their families. Therefore, accurate diagnoses of morbid states in the early stage of the disease and corresponding appropriate treatments should be given high priority. 1. Introduction Parkinson¡¯s disease (PD) is a progressive degenerative disease related to the extrapyramidal system. Patients with this disease show four major symptoms: resting tremor, muscle rigidity, akinesia, and postural reflex disturbance, all of which show a gradual progression. The prevalence rate of PD is 300 cases per 100,000. Although PD is observed over a wide age range, its crisis and prevalence rates generally increase with age. In Japan, the number of PD patients is increasing with the aging of the society. Although the primary cause of PD is the degeneration of the dopamine secretory cells in the mesencephalon substantia nigra pars compacta, the other major causative factors include the degeneration and disappearance of neurons in the noradrenaline system (locus coeruleus), the serotonin system (dorsal raphe nucleus), and the acetylcholine system (basal ganglion of Meynert). As a result, PD patients show various disorders in the motor and nonmotor systems. There has been increasing interest in PD nonmotor symptoms (NMSs). NMSs include various disorders such as mood disorders, cognitive dysfunction, mental symptoms, autonomic nervous system disorders, and perception disorders. These NMSs can be evident in the progressive stage, as well as in the early stages of functional nonmotor disorders related to cognitive, emotional, and behavioral aspects. Therefore, early detection and diagnosis of NMS are important for preventive therapies [1]. Regarding mood disorders presenting as NMS, depression [2], apathy [3], and anhedonia [4] complicate PD and are present at high rates in PD patients (approximately 40%), although these rates differ among the various reports. These complications are important factors that detrimentally affect the patients¡¯ quality of life and care burden [5]. Although apathy and anhedonia are often confused with depression, they differ from depression in terms of mechanisms, therapeutic approaches, and prognoses. If therapy
%U http://www.hindawi.com/journals/isrn.neurology/2011/219427/