Negative symptoms in patients with schizophrenia with special reference to the primary versus secondary distinction

Negative symptoms in schizophrenia represent a diagnostic and therapeutic challenge. Diagnostically, they need to be differentiated from depression and treatment-related variables. The latter include akinesia, a part of drug-induced Parkinsonism, sedation, and effects of understimulation, as they have been reported in patients institutionalised for long periods of time. Other patients show negative symptoms as sequelae of positive symptoms: Commanding voices that tell patients to stay in the house or forbid them to speak to other people, or persecutory delusions may result in social withdrawal and alogia. All of the above, often summarised as secondary negative symptoms, have to be distinguished from primary negative symptoms, sometimes also referred to as the deficit state of schizophrenia. These are considered illness inherent problems and usually have an enduring, chronic course. They are often seen in the absence of positive symptoms, as in simple schizophrenia. The chronicity of the disorder, the lack of obviously disturbed and aberrant behavior and the fact that these patients tend to lead secluded lives lead to an underrepresentation of these patients in clinical psychiatry. Next to a description of clinical symptoms a review of means to aid differential diagnosis is provided. Negative symptoms call for sound differential diagnosis provided by a specialist in order to be able to provide optimal management to prevent the negative consequences of a chronic negative syndrome.