Sydney Melancholia Prototype Index Research Articles

Clinical Characteristics of Melancholic and Nonmelancholic Depressions.

This study aimed to compare clinical-demographic features of melancholic and nonmelancholic depressions. We included 141 depressed inpatients classified as melancholic and nonmelancholic by the Sydney Melancholia Prototype Index (SMPI) and Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) criteria. Results were controlled for confounders, including severity measures. Melancholic patients by both diagnostic systems were more severely depressed and presented more psychotic symptoms, neurological soft signs, and psychomotor disturbances. Melancholic patients classified by the SMPI were also older at illness onset and had fewer suicide attempts. After controlling for confounders, although all differences remained significant for SMPI diagnosis, the DSM-5 diagnosis of melancholia was only associated with further impaired motor sequencing. The results obtained with the SMPI support the hypothesis that melancholia has clinical features qualitatively different from those of nonmelancholic depressions. Contrarily, the DSM-5 specifier seems to reflect the severity of depressive episodes rather than core clinical features of melancholia.

Revisiting the concept of bipolar depression: comparison of diagnostic validators between melancholic and non-melancholic episodes.

The current definition of bipolar disorder derives with minimal changes from one that emerged through expert consensus in the late 1970s, and the topic of its validity tended to be neglected in the literature. The aim of this exploratory study was to compare patients with bipolar disorder with a history of melancholic and non-melancholic depressive episodes in a series of external diagnostic validators. One hundred eight subjects were categorized as melancholic or non-melancholic in relation to their history of depressive episodes through the clinician-rated Sydney Melancholia Prototype Index (SMPI). The external validators used were clinical-demographic variables, family history of bipolar disorder, neurocognitive performance and functional outcome. There were 43.5% of the patients with a history of melancholia and 56.5% of non-melancholic depression. Non-melancholic depressions were overrepresented in females, while melancholic depressions had a female:male ratio closer to unity. Patients with melancholia had more history of BD in first-degree relatives and better functional outcome than those with non-melancholic depression. There were no differences between groups regarding neurocognitive performance. Results tended to be unchanged when controlled for confounders. Our preliminary results highlight the inherent heterogeneity in the current concept of bipolar depression, and suggest the need for further clinical research to elucidate its validity.

Neurocognitive function of patients with melancholic and non-melancholic major depressive episodes: An exploratory study.

The aim of this exploratory study was to compare the neurocognitive performance of patients undergoing melancholic and non-melancholic major depressive episodes. Considering potential limitations of the Diagnostic and Statistical Manual of Mental Disorders (5th ed.) specifier, we employed an additional tool that has proven useful in identifying melancholia (the Sydney Melancholia Prototype Index). One hundred forty-one depressed inpatients were classified as melancholic or non-melancholic according to the Sydney Melancholia Prototype Index and the Diagnostic and Statistical Manual of Mental Disorders (5th ed.) criteria and compared on a neurocognitive battery selected to assess attention and processing speed, verbal memory, working memory and executive functions. Results were controlled for several potential confounders. Patients diagnosed as melancholic by the two diagnostic systems displayed lower scores in executive measures, semantic verbal fluency and phonological verbal fluency. On attention and processing speed, patients with melancholia underperformed those with non-melancholic depression only when diagnosed by the Sydney Melancholia Prototype Index. After controlling for confounders, associations between melancholic status and executive dysfunction remained significant for the Sydney Melancholia Prototype Index but not for the Diagnostic and Statistical Manual of Mental Disorders (5th ed.) diagnosis. In this study, melancholia diagnosed by the Sydney Melancholia Prototype Index (but not by the Diagnostic and Statistical Manual of Mental Disorders [5th ed.] criteria) was characterized by a greater compromise of tests assessing executive functions than non-melancholic depressions, even after controlling for depressive severity. These preliminary results might contribute to generating hypotheses about differences in the cognitive profile and pathophysiological substrate between melancholic and non-melancholic depressions. Likewise, the pattern of findings supports the hypothesis that the Diagnostic and Statistical Manual of Mental Disorders (5th ed.) melancholia specifier might identify more severe forms of depressive episodes rather than a qualitatively different subtype.

The utility of the Sydney Melancholia Prototype Index (SMPI) for predicting response to electroconvulsive therapy in depression: A CARE Network study

An enhanced understanding of clinical predictors of positive ECT outcome could assist with the decision to prescribe ECT for select patients. Reliable predictors of ECT response such as psychotic symptoms and age have been identified, however, studies of melancholia and ECT response have been inconsistent. The Sydney Melancholia Prototype Index (SMPI) is a clinical measure designed to differentiate melancholic and non-melancholic depression. This study aimed to investigate whether melancholic depression (as measured by the clinician rated version of the SMPI) predicted a better response to ECT than non-melancholic depression. The study included data collated from four participating sites in the Clinical Alliance for ECT and Related treatments (CARE) network. The primary outcome was response (>50% improvement) on the Montgomery Asberg Depression Rating Scale (MADRS) and the secondary outcome was raw change in MADRS score. Of the 329 depressed patients included in the study, 81% had melancholic features and 76% met criteria for clinical response. SMPI defined melancholia was associated with older age, higher pre-treatment mood scores and presence of psychosis. Melancholia as defined by the SMPI, however, did not significantly predict either clinical response or overall mood improvement with ECT in multivariate analyses. Instead, older age, greater pre-treatment depression severity and the use of bifrontal compared to right unilateral ultrabrief ECT were significant predictors of mood improvement. Path analysis showed that higher pre-treatment mood score and older age were independently associated with mood improvement with ECT.

Clinical Course in Patients With Melancholic and Nonmelancholic Bipolar Depression.

The aim of the current study was to compare the longitudinal clinical course of patients with a history of melancholic and nonmelancholic bipolar depression. Seventy-seven euthymic outpatients with bipolar disorder were categorized as melancholic or nonmelancholic through the clinician-rated Sydney Melancholia Prototype Index. Clinical course was assessed for a period longer than 48 months by time spent ill, density of affective episodes, severity and duration of depressive episodes, and time to depressive recurrence. The mean follow-up time was 69.05 months. Patients with melancholic depressions had more severe and longer depressive episodes during follow-up, whereas patients with nonmelancholic depressions had a shorter time to depressive recurrence and more subsyndromal depressive symptoms and affective instability. These findings highlight the heterogeneity inherent to the current construct of bipolar depression and position melancholia as an interesting target for comparison with nonmelancholic depressions in other external validators in the field of bipolar disorder.

First-time administration of the Sydney Melancholia Prototype Index (SMPI) to non-English-speaking patients: a study from Brazil.

Objective:The Sydney Melancholia Prototype Index (SMPI) is a scale that uses a non-conventional strategy to assess melancholia status based on prototypic symptoms and illness course variables. This study aimed to evaluate the performance of the first translation of this instrument in a non-English-speaking population.Methods:A sample comprising 106 Brazilian outpatients with depression was evaluated simultaneously with the Brazilian version of the self-rated SMPI (SMPI-SR) and clinician-rated SMPI (SMPI-CR). The kappa coefficient and t test were used to evaluate concurrent validity vs. DSM-IV, CORE system, Hamilton Depression Rating Scale-6 item (HAM-D6), and HAM-D17 assignments to a melancholic or non-melancholic class. The prevalence of melancholia as well as sensitivity and specificity were calculated across instruments.Results:The prevalence of melancholia was highest using DSM-IV criteria (56.6%). The kappa agreement between SMPI-CR and DSM-IV melancholia assignment was moderate (kappa 0.44, p ≤ 0.001). SMPI-CR-assigned melancholic patients had significantly higher CORE, HAM-D17, and HAM-D6 scores. The test-retest consistency values for the SMPI were modest at best, and somewhat superior for the CR version.Conclusion:The Brazilian SMPI-CR presented satisfactory psychometric properties (which were superior to those of the SMPI-SR), and therefore appears to be a useful option for identifying melancholia and studying its causes and optimal treatments.

Melancholia defined with the precision of a machine

BackgroundThe status of melancholia as a categorical or dimensional condition remains unclear, and no measure of melancholia has achieved definitive status. This study aimed to use a machine learning approach to assess whether a pre-established cut-off score on the Sydney Melancholia Prototype Index (SMPI) provided clear differentiation of melancholic/non-melancholic depression, and to identify the items making the most distinct contribution. MethodsWe analysed amalgamated data sets of 1513 clinically depressed patients assessed via the clinician-rated version of the SMPI (SMPI-CR). We also evaluated the self-report version of the SMPI (SMPI-SR) in a combined clinical/community sample of 2025 depressed patients and senior high school students. Rule ensembles were derived in which the outcome measure was the presence/absence of melancholia (defined as scoring at or above a SMPI cut-off score that had been established in previous studies) and the predictive variables were the individual SMPI items. ResultsThe pre-established SMPI cut-off score was confirmed as differentiating melancholic/non-melancholic with near perfect accuracy for the SMPI-CR, and with very high accuracy for the SMPI-SR. The relative importance of all SMPI items was quantified. LimitationsIt is difficult to validate SMPI-assigned diagnoses due to the lack of any similar measures. ConclusionsThe SMPI-CR was confirmed to be a highly precise instrument for differentiating melancholic and non-melancholic depression. Its use will advance clinical decision making and studies evaluating causes, mechanisms and treatments for the two depressive sub-types, as well as assist clarification as to whether melancholia is categorically or dimensionally distinct from non-melancholic depression.

Sydney Melancholia Prototype Index (SMPI): translation and cross-cultural adaptation to Brazilian Portuguese.

Introduction Depression is possibly not a single syndrome but rather comprises several subtypes. DSM-5 proposes a melancholia specifier with phenotypic characteristics that could be associated with clinical progression, biological markers or therapeutic response. The Sydney Melancholia Prototype Index (SMPI) is a prototypic scale aimed to improve the diagnosis of melancholia. So far, there is only an English version of the instrument available. The aim of this study is to describe the translation and adaptation of the English version of the SMPI into Brazilian Portuguese.Methods Translation and cross-cultural adaptation of the self-report (SMPI-SR) and clinician-rated (SMPI-CR) versions into Brazilian Portuguese were done following recommendations of the International Society for Pharmacoeconomics and Outcomes Research (ISPOR). This guideline includes the following steps: preparation, forward translation, reconciliation, back translation, back translation review, harmonization, cognitive debriefing, debriefing results review, proofreading and final report.Results The Brazilian Portuguese versions of the SMPI were well-accepted by respondents. Changes in about two-thirds of the items were considered necessary to obtain the final Brazilian Portuguese version of the SMPI.Conclusions Both versions of the SMPI are now available in Brazilian Portuguese. The instrument could become an important option to enhance studies on melancholia in Portuguese-speaking samples.

Carving depression at its joints? Psychometric properties of the Sydney Melancholia Prototype Index

Parker and colleagues developed the Sydney Melancholia Prototype Index (SMPI), a 24-item measure to assess a potential subtype of depression: melancholia. While research supports the validity of the measure, no study has assessed its psychometric properties. We recruited 1633 participants online, of whom 487 reported a lifetime period of depressed mood or anhedonia and were administered the SMPI. We conducted confirmatory factor analyses (CFA) of the SMPI, to assess the proposed fit of the measure. We also conducted exploratory factor analyses (EFA) to explore the structure implied by the current data. CFA did not support the hypothesized factor structure of the SMPI, no matter what structure we assumed as primary (i.e., a one factor, two factor, or bifactor model). An EFA suggested a five-factor solution wherein several items did not appear to co-vary reliably and other factors captured the severity of melancholic symptoms, negative mood reactivity, positive mood reactivity, emotionality and family relationships, and early life adversity. The SMPI may not measure a single construct. Future research should explore the longitudinal association between depression severity, contaminant symptoms, positive and negative mood reactivity, and early life experiences.

The utility of a classificatory decision tree approach to assist clinical differentiation of melancholic and non-melancholic depression

BackgroundStudies suggest that differentiating melancholic from non-melancholic depressive disorders is advanced by use of illness course as well as symptom variables but, in practice, potentially differentiating variables are generally positioned as having equal value. Judging that differentiating features are more likely to vary in their signal intensity, we sought to determine the number of features required to effect differentiation and their hierarchical order. MethodsThe 24-item clinician-rated Sydney Melancholia Prototype Index (SMPI-CR) was completed for 364 unipolar depressed patients. The sample was divided into two cohorts according to the recruitment period. An RPART classification tree analysis identified the most discriminating SMPI items in the development sample of 197 patients, and examined the sensitivity and specificity of the diagnostic decisions, then sought to replicate findings in a validation sample of 169 patients. ResultsIndependent analyses of putative SMPI items identified only seven items as required to discriminate those with clinically-diagnosed melancholic or non-melancholic depression when the conditions were examined separately. An RPART analysis considering differentiation of melancholic and non-melancholic depression in the total samples retained five of those items in the classification tree, three of which were non-symptom items, and with 92% sensitivity and 80% specificity in the development sample. This reduced item set showed 93% sensitivity and 82% specificity in the validation sample. LimitationsOur clinical judgment of melancholic or non-melancholic depression may not correspond with the clinical logic employed by other clinicians. ConclusionOnly five SMPI items were required to derive a succinct and efficient decision tree, comprising high sensitivity and specificity in differentiating melancholic and non-melancholic depression. Current study findings provide an empirical model that could enrich clinicians׳ approach to differentiating melancholic and non-melancholic depression.

Gender differences in depression severity and symptoms across depressive sub-types

BackgroundLifetime rates of depression are distinctly higher in women reflecting both real and artefactual influences. Most prevalence studies quantifying a female preponderance have examined severity-based diagnostic groups such as major depression or dysthymia. We examined gender differences across three depressive sub-type conditions using four differing measures to determine whether any gender differences emerge more from severity or symptom prevalence, reflect nuances of the particular measure, or whether depressive sub-type is influential. MethodsA large clinical sample was recruited. Patients completed two severity-weighted depression measures: the Depression in the Medically Ill 10 (DMI-10) and Quick Inventory of Depressive Symptoms-Self-Report (QIDS-SR) and two measures weighting symptoms and illness correlates of melancholic and non-melancholic depressive disorders - the Severity of Depressive Symptoms (SDS) and Sydney Melancholia Prototype Index (SMPI). Analyses were undertaken of three diagnostic groups comprising those with unipolar melancholic, unipolar non-melancholic and bipolar depressive conditions. ResultsWomen in the two unipolar groups scored only marginally (and non-significantly) higher than men on the depression severity measures. Women in the bipolar depression group, did however, score significantly higher than men on depression severity. On measures weighted to assessing melancholic and non-melancholic symptoms, there were relatively few gender differences identified in the melancholic and non-melancholic sub-sets, while more gender differences were quantified in the bipolar sub-set. The symptoms most commonly and consistently differentiating by gender were those assessing appetite/weight change and psychomotor disturbance. ConclusionOur analyses of several measures and the minimal differentiation of depressive symptoms and symptom severity argues against any female preponderance in unipolar depression being contributed to distinctly by these depression rating measures. Our analyses indicated that gender had minimal if any impact on depression severity estimates. Gender differences in depressive symptoms and severity were more distinctive in bipolar patients, a finding seemingly not previously identified or reported. LimitationsThe study had considerable power reflecting large sample sizes and thus risks assigning significant differences where none truly exist, although we repeated analyses after controlling for the type I error rate.

DEBATE: ATTENUATED PSYCHOSIS SYNDROME IS A NEEDED DIAGNOSTIC CATEGORY

Lifetime rates of depression are distinctly higher in women reflecting both real and artefactual influences. Most prevalence studies quantifying a female preponderance have examined severity-based diagnostic groups such as major depression or dysthymia. We examined gender differences across three depressive sub-type conditions using four differing measures to determine whether any gender differences emerge more from severity or symptom prevalence, reflect nuances of the particular measure, or whether depressive sub-type is influential.A large clinical sample was recruited. Patients completed two severity-weighted depression measures: the Depression in the Medically Ill 10 (DMI-10) and Quick Inventory of Depressive Symptoms-Self-Report (QIDS-SR) and two measures weighting symptoms and illness correlates of melancholic and non-melancholic depressive disorders - the Severity of Depressive Symptoms (SDS) and Sydney Melancholia Prototype Index (SMPI). Analyses were undertaken of three diagnostic groups comprising those with unipolar melancholic, unipolar non-melancholic and bipolar depressive conditions.Women in the two unipolar groups scored only marginally (and non-significantly) higher than men on the depression severity measures. Women in the bipolar depression group, did however, score significantly higher than men on depression severity. On measures weighted to assessing melancholic and non-melancholic symptoms, there were relatively few gender differences identified in the melancholic and non-melancholic sub-sets, while more gender differences were quantified in the bipolar sub-set. The symptoms most commonly and consistently differentiating by gender were those assessing appetite/weight change and psychomotor disturbance.Our analyses of several measures and the minimal differentiation of depressive symptoms and symptom severity argues against any female preponderance in unipolar depression being contributed to distinctly by these depression rating measures. Our analyses indicated that gender had minimal if any impact on depression severity estimates. Gender differences in depressive symptoms and severity were more distinctive in bipolar patients, a finding seemingly not previously identified or reported.The study had considerable power reflecting large sample sizes and thus risks assigning significant differences where none truly exist, although we repeated analyses after controlling for the type I error rate.

Validation of a new prototypic measure of melancholia

Multiple approaches have been adopted in an attempt to effectively identify and discriminate melancholic and non-melancholic depressive subtypes. We recently developed the Sydney Melancholia Prototype Index (SMPI) which incorporates antecedent and illness course variables as well as symptoms, with clinician-rated and self-rated SMPI versions, and with the former having been shown to have superior sensitivity and specificity in discriminating melancholic from non-melancholic depression. The aim of this study was to further evaluate the capacity of the SMPI to identify melancholia in comparison to DSM-based and clinician-judged assignments. The sample comprised 214 patients diagnosed with melancholic or non-melancholic depression according to a detailed clinical assessment and by the Mini International Neuropsychiatric Structured Interview (MINI) assessing formal DSM-IV melancholia criteria. DSM-IV assignment to melancholic versus non-melancholic depression was contrasted with clinician-judged allocation, the combination of these two strategies (“concordant diagnoses”), and to the SMPI (CR or clinician-rated and SR or self-report versions), with the likely validity of each approach examined against historical ascriptions for melancholia. DSM-IV criteria assigned the highest percentage of the sample with a melancholic diagnosis (64%), whereas the SMPI-SR assigned the smallest percentage with a melancholic diagnosis (37%). DSM-IV assignment was associated with the fewest number of validating variables, whilst SMPI-CR and independent clinician diagnosis were associated with the greatest number of differentiating variables including negative childhood experiences, past and recent stressors, satisfaction with life and perceived social support. These comparative analyses provide further support for the SMPI-CR in identifying and discriminating melancholic depression from non-melancholic depression. Replication of these findings in other samples with independent raters is recommended.

Bipolar depression: Prototypically melancholic in its clinical features

BackgroundNumerous studies have considered whether bipolar depression is phenomenologically similar or different to unipolar depression. While there have been some relatively consistent individual features identified, no clear clinical phenotype has been defined for bipolar depression. MethodsA self-report and clinician-rated measure of the Sydney Melancholia Prototype Index (‘SMPI’) was used to assess prototypic features of melancholic and non-melancholic depression in a sample of 901 patients clinically diagnosed with bipolar disorder or unipolar depression. The majority also completed a self-report (SDS) severity of depression measure, and provided current and historical data on depression, anxiety, global functioning and stressor severity. ResultsComparative analyses favoured the SMPI-CR above the SMPI-SR measure in terms of discriminatory strengths. The previously determined SMPI-CR difference score cut-off of 4 or more for differentiating melancholic from non-melancholic depression was replicated in this larger sample. SMPI item and prototypic pattern analyses indicated that bipolar depression corresponded closely to unipolar melancholic depression in terms of clinical pattern features but not in regard to a number of socio-demographic, illness course and correlate variables. ‘Atypical features’ were common across bipolar and unipolar disorders, but somewhat more prevalent in bipolar disorder. LimitationsThere was no distinction made for the bipolar group between subtypes I and II, with the study simply comparing bipolar with unipolar disorders. The apparent superiority of the clinician-rated in comparison to the SMPI-SR measure may reflect a clinician judgement bias. ConclusionsThe SMPI-CR measure indicated that bipolar depression corresponds closely to melancholic depression in terms of its clinical phenotype.

Discriminating melancholic and non-melancholic depression by prototypic clinical features

Melancholia is positioned as either a more severe expression of clinical depression or as a separate entity. Support for the latter view emerges from differential causal factors and treatment responsiveness but has not been convincingly demonstrated in terms of differential clinical features. We pursue its prototypic clinical pattern to determine if this advances its delineation. We developed a 24-item measure (now termed the Sydney Melancholia Prototype Index or SMPI) comprising 12 melancholic and 12 non-melancholic prototypic features (both symptoms and illness correlates). In this evaluative study, 278 patients referred for tertiary level assessment at a specialized mood disorders clinic completed the self-report SMPI as well as a depression severity measure and a comprehensive assessment schedule before clinical interview, while assessing clinicians completed a clinician version of the SMPI items following their interview. The independent variable (diagnostic gold standard) was the clinician's judgment of a melancholic versus non-melancholic depressive episode. Discriminative performance was evaluated by Receiver Operating Characteristics (ROC) analysis of four strategies for operationalising the SMPI self-report and SMPI clinician measures, and with the former strategies compared to ROC analysis of the depression severity measure. The external validity of the optimally discriminating scores on each measure was tested against a range of clinical variables. Comparison of the two self-report measures established that the SMPI provided greater discrimination than the depression severity measure, while comparison of the self-report and clinician-rated SMPI measures established the latter as more discriminating of clinically diagnosed melancholic or non-melancholic depression. ROC analyses favoured self-report SMPI distinction of melancholic from non-melancholic depression being most optimally calculated by a 'difference' score of at least four or more melancholic than non-melancholic items being affirmed (sensitivity of 0.69, specificity of 0.77). For the clinician-rated SMPI measure, ROC analyses confirmed the same optimal difference score of four or more as highly discriminating of melancholic and non-melancholic depression (sensitivity of 0.84, specificity of 0.92). As the difference score had positive predictive values of 0.90 and 0.70 (for the respective clinician-rated and self-report SMPI forms) and respective negative predictive values of 0.88 and 0.70, we conclude that the clinician-rated version had superior discrimination than the self-report version. External validating data quantified the self-rated and clinician-rated Index-assigned non-melancholic patients having a higher prevalence of anxiety disorders, a higher number of current and lifetime stressors, as well as elevated scores on several personality styles that are viewed as predisposing to and shaping such non-melancholic disorders. Assigned melancholic and non-melancholic diagnoses were determined by clinician judgement, risking a circularity bias across diagnostic assignment and clinical weighting of melancholic and non-melancholic features. The robustness of the Index requires testing in primary and secondary levels of care settings. The clinician-rated SMPI differentiated melancholic and non-melancholic depressed subjects at a higher level of confidence than the self-report SMPI, and with a highly acceptable level of discrimination. The measure is recommended for further testing of its intrinsic and applied properties.