Impulsivity in schizophrenia: phenomenology and research approaches

Impulsivity in schizophrenia is not a solid phenomenon either at the level of behavior or from the point of view of psychological mechanisms and underlying physiology. Some research approaches are considered in the article, and three types of impulsivity were identified based on the difference in research method and object: impulsivity as a clinical condition, impulsivity as a personality trait, and experimentally studied impulsivity. Clinical impulsivity manifests most often as the unmotivated aggression and affective outburst, or as following the psychotic symptoms. The basis for the qualification is the information from observation and interviews with the patient and family members; specific scales are used for standardized assessment. Impulsivity as a personality trait is studied mainly using self-questionnaires and describes various aspects of personality and cognitive style associated with impulsive behavior. The results of the studies in patients with schizophrenia show both higher rates of subjective impulsivity and those comparable with normative data. The third type of impulsivity reveals in controlled experiments with the conditions that provoke impulsive behavior. Data on patients with schizophrenia in the experimental paradigm are also ambiguous. The article discusses the relationships between different types of impulsivity and possible approaches to its therapy and correction in subjects with schizophrenia.