Descriptive Psychopathology: The Signs and Symptoms of ...

374 Section 4: Evidence-based classificationsuppression test), and note that the specificity and sensitivity of such measures aresimilar to those for scalp-recorded EEG in the recognition of seizure disorder. Theyalso recommend the use of a lorazepam challenge test to confirm the diagnosis ofcatatonia. 2 First and Zimmerman (2006) also recommend all-night sleep EEG as anindicator for depressive illness, and report that such a study correctly classified 82%of a mixed sample of normal persons, persons with primary insomnia, and patientswith depression.Some writers place their hopes on classification by gene identification,i.e. genetic nosology. 3 But attempts to delineate specific diseases by specific genotypeare premature as the syndromes of interest are phenotypically ill-defined andlikely multifactorial in etiology. 4Mood disorders 5Since 1980, depressive illness has been defined as the single construct, majordepression, with variations based on illness duration and severity (e.g. dysthymiaand psychotic depression). Abnormal bereavement and perinatal depression are givenseparate status. Modest depressions associated with personal stress are designatedadjustment disorder. Persons with only recurrent depressive episodes are classified asunipolar. Those who also experience hypomania or mania are said to be bipolar andto be suffering from a different illness requiring different treatments. 6Clinical presentations and pathophysiology of the unipolar form are consideredto be so alike that similar treatments are offered, varying mainly in dosage,numbers of agents, or augmentations. The recommended treatment algorithmsare the same for all patients with non-psychotic major depression, and slightlymodified for patients with psychotic depression and bipolar depression.Research and clinical samples of depressed patients selected by list criteria,however, are heterogeneous and account in part for poor treatment outcomes. 7Predictors of good outcomes with newer antidepressants have not been identified.Similar critiques are offered for the poor outcomes in the STEP-BD study of antimanicagents 8 and the CATIE study of atypical antipsychotics. 9Dividing the major depression category into melancholia and non-melancholiadepressive disorders is an alternative paradigm to the present classification ofmood disorders that fits the evidence better. This approach minimizes intra-sampleheterogeneity and encourages more specific treatments and precise research. Thedivision also alters the category’s unipolar–bipolar formulation (see below).While several present categories can be combined in the melancholia construct,non-melancholic depression remains heterogeneous. Dysthymia is not a validentity and likely represents patients with poorly treated depressive illness, depressivedisorders that are exaggerations of temperament traits (depressive personality),