Negative symptoms in primary psychotic transtornos include constricted, blunted, or flat affect, alogia or paucity of speech, avolition (general lack of drive, or lack of motivation to pursue meaningful goals), asociality (reduced or absent engagement com others and interest in social interaction) and anhedonia (inability to experience pleasure from normally pleasurable activities). To be considered negative psychotic symptoms, relevant symptoms should not be entirely attributable to antipsychotic drug treatment, a depressive transtorno, or an under-stimulating environment, and should not be a direct consequence of a positive symptom (e.g., persecutory delusions causing a person to become socially isolated due to fear of harm). The rating should be made based on the severity of negative symptoms during the past week.