Descriptive Psychopathology: The Signs and Symptoms of ...

383 Chapter 16: An evidence-based classificationRather than the present separation of mood disorders into bipolar and unipolargroups, a better formulation is: (1) melancholia with or without mania or hypomania,catatonia, or psychosis, and (2) non-melancholia disorders. Abnormalbereavement and perinatal depressive conditions are melancholic depressions anddo not warrant separate classification. The delineation of the non-melancholiccategory awaits further study.Psychotic disordersPsychotic disorders are defined by the presence of hallucinations or delusions.Although mood disorders and delirium are frequently accompanied by psychosis,they are separately classified. The distinction of “always” for the psychosis categoryversus “frequent” for the others is arbitrary and diagnostically imprecise. Classifyingby these non-specific features is equivalent to classifying infectious disease bythe presence or absence of fever. Latent class analyses of patients with psychosis donot support the present classification, concluding that the present system obscuressubtle but meaningfully different illness forms. 97 A psychosis category encouragesfalse positive diagnoses, i.e. a manic or melancholic patient is hallucinating anddelusional, and therefore is given one of the psychotic disorder diagnoses. Thepsychosis category should be eliminated and its valid conditions, i.e. delusionaldisorder and schizophrenia, independently placed in the classification. The termschizophrenia, however, has less meaning than Kraepelin’s dementia praecox. Itrepresents a heterogeneous population most suffering from a chronic psychoticdisorder.The psychosis category’s organization is also arbitrary and includes conditions ofweak validity. The separation of schizophrenia, schizophreniform and brief psychoticdisorder by the duration of their acute psychosis phase (>6months, 1, and