This is an open access article distributed under the terms of Creative Commons Attribution License. Negative symptoms have long been recognized as a core feature of schizophrenia since the first description of the disease and remain unmet treatment targets.
Even though negative symptoms represent a heterogeneous syndrome, there is now a consensus regarding its constitutive factors, which encompass blunted affect, alogia, social withdrawal, avolition, and anhedonia 1. An important distinction has been made in the last decades between primary and secondary negative symptoms. The primary ones are considered to be intrinsic to the disease. Secondary ones are the result of other categories of symptoms such as positive symptoms, depressive symptoms, cognitive deficits, extrapyramidal side effects, or social deprivation or chronic consumptive disorders.
Unlike primary negative symptoms, which are not adequately targeted by current interventions, secondary negative symptoms respond to treatment of the underlying cause 2 , 3.
There are several reasons why there is a growing interest in developing treatments, specifically targeting primary negative symptoms. First, negative symptoms of schizophrenia are a significant contributor to poor functional outcomes and low quality of life to a greater extent than positive symptoms The lack of approved treatments for this group of symptoms emerges from the fact that no treatment has been proven effective and reliable from large clinical trials 5 , 8.
The present review aims to provide a general overview of the recent research into pharmacological treatment approaches targeting negative symptoms of schizophrenia. This is a selective review of the literature published between and We decided to focus on this period, as many advances have been achieved to treat negative symptoms.
