Attempts to Validate Melancholic Depression: Some Observations on Modern Research Methodology

Subtypes of depression and their overlap in a naturalistic inpatient sample of major depressive disorder

Subtyping depression is important in order to further delineate biological causes of depressive syndromes. The aim of this study was to evaluate clinical and outcome characteristics of distinct subtypes of depression and to assess proportion and features of patients fulfilling criteria for more than one subtype. Melancholic, atypical and anxious subtypes of depression were assessed in a naturalistic sample of 833 inpatients using DSM-IV specifiers based on operationalized criteria. Baseline characteristics and outcome criteria at discharge were compared between distinct subtypes and their overlap. A substantial proportion of patients (16%) were classified with more than one subtype of depression, 28% were of the distinct anxious, 7% of the distinct atypical and 5% of the distinct melancholic subtype. Distinct melancholic patients had shortest duration of episode, highest baseline depression severity, but were more often early improvers; distinct anxious patients had higher NEO-Five Factor Inventory (NEO-FFI) neuroticism scores compared with patients with unspecific subtype. Melancholic patients with overlap of anxious features had worse treatment outcome compared to distinct melancholic and distinct anxious subtype. Distinct subtypes differed in only few variables and patients with overlap of depression subtypes may have independent clinical and outcome characteristics. Studies investigating biological causes of subtypes of depression should take influence of features of other subtypes into account.

Baseline cognitive function does not predict the treatment outcome of electroconvulsive therapy (ECT) in late-life depression

BACKGROUND

No prior study has investigated whether impairment of specific cognitive functions at baseline may predict the short-term treatment outcome of electroconvulsive therapy (ECT) in elderly non-demented patients with major depression (MD).

METHODS

This longitudinal cohort study included 65 elderly patients with unipolar or bipolar MD, aged 60-85 years, treated with formula-based ECT. Treatment outcome was assessed using the 17-item Hamilton Rating Scale for Depression (HRSD17). Cognitive function at baseline was assessed using nine neuropsychological tests or subtests measuring information processing speed, verbal learning and memory, and aspects of executive function.

RESULTS

A poorer performance on the word reading task of the Color Word Interference Test rendered higher odds of achieving remission during the ECT course (p=0.021). Remission was defined as an HRSD17 score of 7 or less. There were no other significant associations between the treatment outcome of ECT and cognitive performance parameters assessed at baseline.

LIMITATIONS

The limited number of subjects may have reduced the generalizability of the findings. Multiple statistical tests increase the risk for making a type I error.

CONCLUSIONS

How well patients perform on neuropsychological tests at baseline is most likely not a predictor of, or otherwise not significantly associated with the treatment outcome of formula-based ECT in elderly patients with MD.

Unipolar and bipolar depression: different of the same?

The diagnostic boundary between recurrent unipolar depression and bipolar disorder may not be clear-cut and, further, the symptoms of unipolar depression compared with bipolar depression (although similar) are subtly different. Here we review the potential implications for clinical practice and research of new thinking about the relationship between recurrent unipolar depression and bipolar disorder.