Negative symptoms: History of the concept and their position in diagnosis of schizophrenia.

Current conceptualizations of schizophrenia have been introduced over centuries and continue to progress in recent decades. Symptoms have been divided into several domains, contrasting negative and positive symptoms which are different in their nature, onset, progression and response to treatment. An account of the different historical changes of the concept – essentially nosographic – has led to models attempting to integrate findings for each dimension of the disorder. This paper reviews the history of negative symptoms in diagnosis and how different approaches have been utilised to consider negative symptoms in the concept of schizophrenia. The paper also bridges various international classifications which have evolved and modified the role of negative symptoms in their diagnostic criteria for schizophrenia, which highlights the challenge of defining this disease.