L’apathie dans la schizophrénie : une revue clinique et critique de la question

Abstract

Today the concept of apathy is subject to many questions. This psychological state is present and predominant in different disorders such as neurodegenerative and psychiatric diseases or neurological acquired disorders. Apathy is a part of the clinical vocabulary, however, we can note that in the literature there remains confusion in its definition, and we can find an amalgam with other clinical symptoms. The aim of this review is to provide a clarification of the concept of apathy in clinical practice in schizophrenia as well as to highlight the gaps that exist. Apathy belongs to the negative symptoms of schizophrenia. For its understanding, it is necessary to define apathy as a multidimensional syndrome (cognitive, emotional, and behavioral) manifesting as a quantitative reduction of voluntary behaviors directed toward one or several goals. However, at present, we are witnessing a reductionist and simplistic conception of the syndrome of apathy and this especially in the Anglo-Saxon literature. Several authors reduce apathy to its behavioral component, so in other words, to avolition/amotivation. Avolition refers to a loss of self-initiated and spontaneous behaviors. In this definition only observable behavior is taken into account and not the underlying mechanisms (cognitive and emotional). In order to understand the syndrome of apathy, it is necessary to have a holistic and multidimensional outlook. Some authors have proposed diagnostic criteria for apathy by taking into account the different dimensions of apathy. Moreover not only is apathy confused with avolition, but it is also still difficult to distinguish it from depression. Apathy and depression share common clinical signs (i.e. loss of interest), but they also have distinct clinical signs (lack of motivation for apathy, and suicidal ideation for depression). Authors have shown that the presence of one symptom (apathy or depression) does not predict the presence of the other. An apathetic patient does not have to be necessarily in a depressive state and vice versa. However, to our knowledge, there is no data capable of distinguishing depression from apathy in schizophrenia, and knowing what is the part of one and the other when the patient has both symptoms. In addition, we can see that the confusion that persists between those two symptoms also stems from assessment tools. Indeed, some assessment tools such as the Montgomery and Asberg Depression Rating Scale (MARDS) have an apathy subscale. Therefore, this scale does not only evaluate depression. Regarding the assessment of apathy in schizophrenia, there are specific and nonspecific tools. Nonspecific tools define apathy differently. For this reason, authors have proposed to measure apathy by using analytic factors of negative symptoms. In this case, apathy is going to be assessed by the factor "motivation/pleasure" including anhedonia, asociality and avolition. This factor will provide the possibility of a better assessment of apathy. Concerning specific scales (like AES), there are gaps such as a lack of standardization in the execution and the quotation. Furthermore, no scale takes into account the factors causing apathy. Knowing the reasons for apathy is necessary because this syndrome is frequent in schizophrenia, and it is found in the different phases of this disease (prodromal, first episode psychosis, and chronic). In addition, apathy has significant functional consequences on the patient's quality of life, as well as on his or her global functioning. Indeed, apathy impacts on his or her social and professional life. Patients with schizophrenia have a loss of autonomy, less employment and social withdrawal. Consequently, interest in its drug or treatment it is obvious. However, drug and non-drug treatments are not specific to apathy and therefore little effective on this syndrome. Implications to stimulate future research are presented.