Schizophrenia spectrum and other psychotic disorders include schizophrenia, schizoaffective disorder, delusional disorder, schizotypal personality disorder, schizophreniform disorder, brief psychotic disorder, substance-induced psychotic disorder, alcohol-induced psychotic disorder, and nonclinical psychosis. Each of these disorders is defined by abnormalities in one or more of the following symptoms: hallucinations, delusions, disorganized speech, grossly disorganized or catatonic behavior, and negative symptoms (negative symptoms include problems with motivation, social interactions, affective experience and responsiveness, prosody and clarity of speech, and slowed movement). Defined by the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), distinctions in classification focus on differing levels of frequency, impairment, or duration. In terms of diagnostic classification, there has not been a great deal of change between the previous edition of the DSM (DSM-IV) and ...