Can the DSM's major depression bereavement exclusion be validly extended to other stressors? Evidence from the NCS

Assessing the disproportionality of depressive reactions to life stress

BACKGROUND

Prior to DSM-5, depression had long been conceptualized as symptoms without cause or disproportionate to one's circumstances. A central challenge to considering whether a depressive reaction is disproportionate is the lack of measures assessing disproportionality. Drawing on a study of patients participating in cognitive behavioural therapy for depression, we evaluate two new measures of the disproportionality of one's depressive symptoms to their recent life circumstances.

METHODS

To assess the disproportionality of depressive symptoms, we developed an interview-based assessment and a brief self-report measure. We employed both assessments in a sample of 126 patients who participated in cognitive behavioural therapy for depression.

RESULTS

Initial evidence for the reliability and validity of both self-report and interview-based approaches appeared promising. Interview judges demonstrated strong inter-rater reliability on life stress ratings, and both forms of disproportionality showed a pattern of correlations with variables reflecting greater clinical complexity, including self-reported personality dysfunction and symptom severity. Comorbid generalized anxiety disorder (GAD) was the only previously proposed marker of complicated depression to significantly predict both disproportionality scores.

LIMITATIONS

The sample had limited ethnic diversity and tended to be highly educated. Participants all met criteria for major depressive disorder and sought treatment.

CONCLUSIONS

Two assessments of the disproportionality of depressive reactions demonstrated evidence of reliability and validity. Despite limited efforts at assessment to date, these results suggest these measures may be able to reliably distinguish the disproportionality of depressive reactions and allow clinicians to better assess contextual life stress depressive disorders.

Heterogeneity in major depression and its melancholic and atypical specifiers: a secondary analysis of STAR*D

OBJECTIVES

The melancholic and atypical specifiers for a major depressive episode (MDE) are supposed to reduce heterogeneity in symptom presentation by requiring additional, specific features. Fried et al. (2020) recently showed that the melancholic specifier may increase the potential heterogeneity in presenting symptoms. In a large sample of outpatients with depression, our objective was to explore whether the melancholic and atypical specifiers reduced observed heterogeneity in symptoms.

METHODS

We used baseline data from the Inventory of Depression Symptoms (IDS), which was available for 3,717 patients, from the Sequenced Alternatives to Relieve Depression (STAR*D) trial. A subsample met criteria for MDE on the IDS ("IDS-MDE"; N =2,496). For patients with IDS-MDE, we differentiated between those with melancholic, non-melancholic, non-melancholic, atypical, and non-atypical depression. We quantified the observed heterogeneity between groups by counting the number of unique symptom combinations pertaining to their given diagnostic group (e.g., counting the melancholic symptoms for melancholic and non-melancholic groups), as well as the profiles of DSM-MDE symptoms (i.e., ignoring the specifier symptoms).

RESULTS

When considering the specifier and depressive symptoms, there was more observed heterogeneity within the melancholic and atypical subgroups than in the IDS-MDE sample (i.e., ignoring the specifier subgroups). The differences in number of profiles between the melancholic and non-melancholic groups were not statistically significant, irrespective of whether focusing on the specifier symptoms or only the DSM-MDE symptoms. The differences between the atypical and non-atypical subgroups were smaller than what would be expected by chance. We found no evidence that the specifier groups reduce heterogeneity, as can be quantified by unique symptom profiles. Most symptom profiles, even in the specifier subgroups, had five or fewer individuals.

CONCLUSION

We found no evidence that the atypical and melancholic specifiers create more symptomatically homogeneous groups. Indeed, the melancholic and atypical specifiers introduce heterogeneity by adding symptoms to the DSM diagnosis of MDE.

DSM-5, psychiatric epidemiology and the false positives problem

The revision effort leading to the publication of the fifth edition of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM-5) was flawed in process, goals and outcome. The revision process suffered from lack of an adequate public record of the rationale for changes, thus shortchanging future scholarship. The goals, such as dimensionalising diagnosis, incorporating biomarkers and separating impairment from diagnosis, were ill-considered and mostly abandoned. However, DSM-5's greatest problem, and the target of the most vigorous and sustained criticism, was its failure to take seriously the false positives problem. By expanding diagnosis beyond plausible boundaries in ways inconsistent with DSM-5's own definition of disorder, DSM-5 threatened the validity of psychiatric research, including especially psychiatric epidemiology. I present four examples: increasing the symptom options while decreasing the diagnostic threshold for substance use disorder, elimination of the bereavement exclusion from major depression, allowing verbal arguments as evidence of intermittent explosive disorder and expanding attention-deficit/hyperactivity disorder to adults before addressing its manifest false positives problems.