Dysfunctional attitudes as a moderator of pharmacotherapy and psychotherapy for chronic depression

OBJECTIVE

Individuals with chronic depression exhibit heterogeneous responses to treatment. Important individual differences may therefore exist within this particularly difficult to treat population that act as moderators of treatment response.

METHOD

The present study examined whether pretreatment levels of dysfunctional attitudes (DA) moderated treatment response in a large sample of chronically depressed individuals. Data were taken from the Research Evaluating the Value of Augmenting Medication with Psychotherapy (REVAMP) treatment study--a multi-site treatment and augmentation study of 808 chronically depressed individuals. REVAMP comprised two phases: 1) a 12-week open-label antidepressant trial and 2), a subsequent phase, in which phase 1 non-remitters (N = 491) were randomized to either receive an ongoing medication algorithm alone, medication plus cognitive behavioral analysis system of psychotherapy, or medication plus brief supportive psychotherapy.

RESULT

In phase 1, compared to the pharmacotherapy response of patients with lower DA scores, the response for patients with higher DA scores was steeper, but leveled off toward the end of the phase. In phase 2, DA predicted a differential response in the medication only arm, but not in the two psychotherapy + medication conditions. Specifically, in the phase 2 medication only condition, patients with higher DA improved while those with lower DA scores did not.

CONCLUSION

These results indicate that the relation between DA and treatment response in chronic depression is complex, but suggest that greater DA may be associated with a steeper reduction and/or better response to pharmacotherapy.

Relation between Respiratory Sinus Arrythymia and Startle Response during Predictable and Unpredictable Threat

Research suggests that lower respiratory sinus arrhythmia (RSA) is associated with greater aversive responding. One physiological indicator of aversive responding is startle potentiation. While a few studies have demonstrated an inverse association between RSA and startle potentiation, no study to date has distinguished whether this relation is similar for predictable versus unpredictable aversive stimuli. This is an important distinction, given that degree of predictability has been shown to be an important determinant of aversive responding. The present study examined whether resting RSA was associated with startle eye blink responding during predictable and unpredictable threat of electric shock. Resting RSA was collected during a 6-minute seated baseline phase at the beginning of the experimental session. Participants then completed a computerized startle task in which predictable and unpredictable shocks were administered. Results indicated that lower resting RSA was associated with greater startle potentiation during unpredictable threat, but not during predictable threat. These findings are consistent with a growing body of literature suggesting that individual differences in RSA are associated with aversive responding, and extend previous work by suggesting that RSA may be more robustly associated with a heightened sensitivity to unpredictable threat. This pattern of results may have implications for the understanding of pathological anxiety given that individuals with anxiety disorders typically exhibit low RSA and heightened responding during unpredictable threat.

A psychophysiological investigation of threat and reward sensitivity in individuals with panic disorder and/or major depressive disorder

Heightened sensitivity to threat and reduced sensitivity to reward are potential mechanisms of dysfunction in anxiety and depressive disorders, respectively. However, few studies have simultaneously examined whether these mechanisms are unique or common to these disorders. In this study, sensitivity to predictable and unpredictable threat (measured by startle response during threat anticipation) and sensitivity to reward (measured by frontal electroencephalographic [EEG] asymmetry during reward anticipation) were assessed in 4 groups (N = 191): those with (1) panic disorder (PD) without a lifetime history of depression, (2) major depression (MDD) without a lifetime history of an anxiety disorder, (3) comorbid PD and MDD, and (4) controls. General distress/negative temperament (NT) was also assessed via self-report. Results indicated that PD (with or without comorbid MDD) was uniquely associated with heightened startle to predictable and unpredictable threat, and MDD (with or without comorbid PD) was uniquely associated with reduced frontal EEG asymmetry. Both psychophysiological measures of threat and reward sensitivity were stable on retest approximately 9 days later in a subsample of participants. Whereas the comorbid group did not respond differently on the tasks relative to the PD-only and MDD-only groups, they did report greater NT than these 2 groups (which did not differ from each other). Results suggest that heightened sensitivity to threat and reduced sensitivity to reward may be specific components of PD and MDD, respectively. In addition, relative to noncomorbid depression and PD, comorbid MDD and PD may be characterized by heightened NT, but not abnormal levels of these "specific" components.

Lifetime rates of psychopathology in single versus multiple diagnostic assessments: comparison in a community sample of probands and siblings

Lifetime prevalence rates of psychopathology vary a great deal depending on whether they are estimated from cross-sectional or prospective longitudinal studies, with the former yielding significantly lower rates. Such findings, however, come from comparisons of separate studies from different countries and cohorts. Here, we compare lifetime rates of psychopathology between a community sample of individuals assessed on multiple occasions to their siblings who completed only a single diagnostic evaluation. Data come from the Oregon Adolescent Depression Project. We included 442 original participants who completed four prospective diagnostic assessments over the course of fifteen years, and 657 of their siblings who completed a single lifetime assessment. Comparisons of rates of depressive, bipolar, anxiety, and substance use disorders were made using survival analysis. We found that rates of depressive disorders, specifically major depressive disorder, were elevated among individuals who completed multiple diagnostic assessments relative to individuals who completed a single lifetime assessment. We did not find significant differences in rates of aggregate anxiety, bipolar, or substance use disorders. Within a single cohort, cross-sectional surveys appear to underestimate the lifetime rates of major depression relative to prospective, longitudinal designs. This suggests that disorders with an episodic course may be under-reported in cross-sectional surveys. Rates of anxiety, bipolar, and substance use disorders did not differ across assessment methods. To further evaluate method effects on lifetime estimates of psychopathology, future work may benefit from comparing rates of retrospectively- and prospectively-derived diagnoses in individuals who are repeatedly assessed over a lengthy follow-up period.

Parsing trait and state effects of depression severity on neurocognition: Evidence from a 26-year longitudinal study

Cognitive dysfunction in mood disorders falls along a continuum, such that more severe current depression is associated with greater cognitive impairment. It is not clear whether this association reflects transient state effects of current symptoms on cognitive performance, or persistent, trait-like differences in cognition that are related to overall disorder severity. We addressed this question in 42 unipolar and 47 bipolar participants drawn from a 26-year longitudinal study of psychopathology, using measures of attention/psychomotor processing speed, cognitive flexibility, verbal fluency, and verbal memory. We assessed (a) the extent to which current symptom severity and past average disorder severity predicted unique variance in cognitive performance; (b) whether cognitive performance covaried with within-individual changes in symptom severity; and (c) the stability of neurocognitive measures over six years. We also tested for differences among unipolar and bipolar groups and published norms. Past average depression severity predicted performance on attention/psychomotor processing speed in both groups, and in cognitive flexibility among unipolar participants, even after controlling for current symptom severity, which did not independently predict cognition. Within-participant state changes in depressive symptoms did not predict change in any cognitive domain. All domains were stable over the course of six years. Both groups showed generalized impairment relative to published norms, and bipolar participants performed more poorly than unipolar participants on attention/psychomotor processing speed. The results suggest a stable relationship between mood disorder severity and cognitive deficits.

The predictive power of depression screening procedures for veterans with coronary artery disease

Depression leads to a worse outcome for patients with coronary artery disease (CAD). Thus, accurately identifying depression in CAD patients is imperative. In many veterans affairs (VA) hospitals, patients are screened for depression once a year using the patient health questionnaire (PHQ-9). Although the PHQ-9 is generally considered a specific and sensitive measure of depression, there is reason to believe that these screening procedures may miss a large number of cases of depression within CAD patients and cardiology patients more generally. The goal of this study was to provide data as to the predictive power of this depression screening procedure by (a) comparing the prevalence rate of depression identified by the PHQ-9 to known prevalence rates and (b) examining whether patients identified as “depressed” also had conditions that consistently co-occur with depression (eg, post-traumatic stress disorder [PTSD], other medical issues). Participants were 813 consecutive patients who received an angiogram in the cardiac catheterization laboratory at a large VA Medical Center. Prevalence of depression was 6.9% in the overall sample and less than 6% when the sample was restricted to CAD patients with significant stenosis. Depression was significantly associated with PTSD, smoking, and alcohol problems. However, depression was not associated with other medical problems such as diabetes, renal failure, peripheral vascular disease, or anemia. In conclusion, the low prevalence rate of depression and lack of associations with comorbid medical problems may suggest that the VA’s depression screening procedures have low sensitivity for identifying depression in CAD patients. It is recommended that clinicians treating CAD regularly screen for depression and do not rely on archival depression screens.

Frontal brain asymmetry in depression with comorbid anxiety: a neuropsychological investigation

The approach-withdrawal model posits that depression and anxiety are associated with a relative right asymmetry in frontal brain activity. Most studies have tested this model using measures of cortical brain activity such as electroencephalography. However, neuropsychological tasks that differentially use left versus right frontal cortical regions can also be used to test hypotheses from the model. In two independent samples (Study 1 and 2), the present study investigated the performance of currently depressed individuals with or without a comorbid anxiety disorder and healthy controls on neuropsychological tasks tapping primarily left (verbal fluency) or right (design fluency) frontal brain regions. Across both samples, results indicated that comorbid participants performed more poorly than depressed only and control participants on design fluency, while all groups showed equivalent performance on verbal fluency. Moreover, comorbid participants showed "asymmetrical" performance on these two tasks (i.e., poorer design [right frontal] relative to verbal [left frontal] fluency), whereas depressed only and control participants showed approximately symmetrical profiles of performance. Results from these two samples suggest an abnormal frontal asymmetry in neurocognitive performance driven primarily by right frontal dysfunction among anxious-depressed individuals and highlight the importance of considering comorbid anxiety when examining frontal brain functioning in depression.

Does intolerance of uncertainty predict anticipatory startle responses to uncertain threat?

Intolerance of uncertainty (IU) has been proposed to be an important maintaining factor in several anxiety disorders, including generalized anxiety disorder, obsessive-compulsive disorder, and social phobia. While IU has been shown to predict subjective ratings and decision-making during uncertain/ambiguous situations, few studies have examined whether IU also predicts emotional responding to uncertain threat. The present study examined whether IU predicted aversive responding (startle and subjective ratings) during the anticipation of temporally uncertain shocks. Sixty-nine participants completed three experimental conditions during which they received: no shocks, temporally certain/predictable shocks, and temporally uncertain shocks. Results indicated that IU was negatively associated with startle during the uncertain threat condition in that those with higher IU had a smaller startle response. IU was also only related to startle during the uncertain (and not the certain/predictable) threat condition, suggesting that it was not predictive of general aversive responding, but specific to responses to uncertain aversiveness. Perceived control over anxiety-related events mediated the relation between IU and startle to uncertain threat, such that high IU led to lowered perceived control, which in turn led to a smaller startle response. We discuss several potential explanations for these findings, including the inhibitory qualities of IU. Overall, our results suggest that IU is associated with attenuated aversive responding to uncertain threat.

Defining reactivity: how several methodological decisions can affect conclusions about emotional reactivity in psychopathology

There are many important methodological decisions that need to be made when examining emotional reactivity in psychopathology. In the present study, we examined the effects of two such decisions in an investigation of emotional reactivity in depression: (1) which (if any) comparison condition to employ; and (2) how to define change. Depressed (N = 69) and control (N = 37) participants viewed emotion-inducing film clips while subjective and facial responses were measured. Emotional reactivity was defined using no comparison condition (i.e., raw scores), baseline comparison condition (i.e., no stimulus presented), and neutral comparison condition (i.e., neutral stimulus presented). Change in emotional reactivity was assessed using four analytic approaches: difference scores, percentage change, residualised change, and ANCOVA. Results differed among the three comparison conditions and among several of the analytic approaches. Overall, our investigation suggests that choosing a comparison condition and the definition of change can significantly influence the presence of group differences in emotional reactivity. Recommendations for studies of emotional reactivity in psychopathology are discussed.

Do positive and negative temperament traits interact in predicting risk for depression? A resting EEG study of 329 preschoolers

Researchers have long been interested in whether particular temperamental traits in childhood connote risk for depressive disorders. For example, children characterized as having high negative emotionality (NE; sadness, fear, anger) and low positive emotionality (PE; anhedonia, listlessness, and lack of enthusiasm) are hypothesized to be at risk for depression. Few studies, however, have examined whether (and how) these two temperamental dimensions interact to confer risk. In a sample of 329 preschoolers, the present study addressed this question by examining the relation between PE and NE and asymmetry in resting EEG activity in frontal and posterior regions, which are putative biomarkers for depression. Using a laboratory battery to define temperament, we found an interaction of PE and NE on posterior asymmetry. Specifically, when PE was high, NE was associated with greater relative right activity. When PE was low, NE was not related to posterior asymmetry. These results were driven by differences in EEG activity in right posterior regions, an area associated with emotional processing and arousal, and were specific to girls. We found no relation between temperament and frontal asymmetry. These findings suggest that, at least for girls, PE and NE may have an interactive effect on risk for depression.

The effect of pre- vs. post-reward attainment on EEG asymmetry in melancholic depression

Clinical investigators have long theorized about the role of reward processing and positive affect in depression. One theory posits that compared to nonmelancholic depressives, melancholic depressives experience less consummatory (i.e., post-reward), but comparably low anticipatory (prior to reward), positive affect. We tested whether frontal EEG asymmetry, a putative marker of the anticipatory reward system, is present only before an individual receives a reward or also after receiving a reward (i.e., during consummatory reward processing). We also examined whether melancholic depression, a condition characterized by a deficit in consummatory reward processing, is associated with abnormal EEG asymmetries in alpha band power. Effects in other frequency bands (delta, theta, or beta) were also explored. EEG was recorded in 34 controls, 48 nonmelancholic depressives, and 17 melancholic depressives during a slot machine task designed to elicit anticipatory and consummatory reward processing. Results indicated that, for alpha, the frontal EEG asymmetry of greater relative left activity was specific to anticipatory reward processing. During the consummatory phase, individuals with melancholic depression exhibited different posterior EEG asymmetries than individuals with nonmelancholic depression (and controls at a trend level). This second finding was largely due to melancholics exhibiting relatively lower right posterior activity and nonmelancholics exhibiting relatively lower left activity. These results suggest that a posterior asymmetry may be a marker for melancholic depression and aberrant consummatory reward processing.

Effect of acute tryptophan depletion on emotions in individuals with personal and family history of depression following a mood induction

BACKGROUND

Acute tryptophan depletion (ATD) has shown depletion-specific increases in depressed mood and overall depressive symptoms, especially in those with a family history and in remitted patients. However, its effect on a broad range of emotions beyond depressed mood has been inconsistent, and studies have rarely employed a negative mood induction.

METHOD

The present double-blind study administered tryptophan-depleted and taste-matched placebo challenge drinks to individuals with a past diagnosis and family history of depression (i.e. depression-vulnerable subjects) and controls in order to investigate the effect of ATD on positive affect, anxiety, anger and depressed mood following a negative mood induction.

RESULTS

Certain aspects of positive affect decreased due to ATD in the depression vulnerables but not in the controls. No differential effects were found on depressed mood and anxiety.

CONCLUSIONS

A stress-induced blunted hedonic capacity may increase vulnerability to ATD and may be a core emotional abnormality in depression. Additionally, serotonin may have a stronger influence on positive affect than on other depression-related emotions during periods of stress.

Does physical anhedonia play a role in depression? A 20-year longitudinal study

BACKGROUND

Anhedonia towards physical or sensory experiences (i.e., physical anhedonia) has most often been examined as a differentia of schizophrenia and not depression, despite the fact that general anhedonia is a core feature of many models of Major Depressive Disorder (MDD).

METHODS

Forty-nine participants with non-psychotic MDD were recruited from inpatient settings and followed-up six times over 20 years. The three aims of the study was to assess a) the stability of physical anhedonia over time, b) whether physical anhedonia relates to the course of depressive symptoms over time, and c) whether physical anhedonia relates to three domains of functioning - work, social functioning, or re-hospitalizations.

RESULTS

We found that over time physical anhedonia was relatively stable and related to depressive symptoms (both between and within person). Physical anhedonia was also related to certain aspects of functioning, though less robustly than depressive symptoms.

LIMITATIONS

Because depressive symptoms, functioning, and physical anhedonia were measured concurrently at each follow-up, the direction of causality among these variables could not be assessed. Additionally, because our sample was recruited from inpatient settings, our findings may not generalize to individuals with less severe depression.

CONCLUSIONS

A trait tendency to experience decreased pleasure to positive physical stimuli is a clinically meaningful variable for those with MDD and may be a behavioral endophenotype for a more severe form of depression.

Subthreshold conditions as precursors for full syndrome disorders: a 15-year longitudinal study of multiple diagnostic classes

BACKGROUND

There has been increasing interest in the distinction between subthreshold and full syndrome disorders and specifically whether subthreshold conditions escalate or predict the onset of full syndrome disorders over time. Most of these studies, however, examined whether a single subthreshold condition escalates into the full syndrome form of that disorder. Equally important, though, is whether subthreshold conditions are likely to develop other full syndrome disorders and whether these associations are maintained after adjusting for comorbidity.

METHODS

A 15-year longitudinal study of subthreshold psychiatric conditions was conducted with 1,505 community-drawn young adults. We examined whether 1) subthreshold major depression, bipolar, anxiety disorders, alcohol use, substance use, conduct disorder and/or ADHD were precursors for the corresponding (homotypic) full syndrome disorder; 2) subthreshold conditions were precursors for other (heterotypic) full syndrome disorders; and 3) these homotypic and heterotypic precursors persisted after adjusting for comorbidity.

RESULTS

Subthreshold major depression, anxiety, alcohol use, substance use, and conduct all escalated into their corresponding full syndrome and nearly all homotypic developments were maintained after adjusting for comorbid subthreshold and full syndrome conditions. Many heterotypic associations were also observed and most remained after controlling for comorbidity, particularly among externalizing disorders (e.g., alcohol, substance, conduct/antisocial personality disorder).

CONCLUSIONS

Many subthreshold conditions have predictive validity as they may represent precursors for full syndrome disorders. Alternatively, dimensional conceptualizations of psychopathology which include these more minor conditions may yield greater validity. Subthreshold conditions may represent good targets for preventive interventions.

Independent associations between personality traits and clinical characteristics of depression

Few studies have examined age of onset and chronicity of depression in the same subject sample. The present study sought to determine whether personality traits related to early onset depression were different from those related to chronic depression. We tested the associations between personality self-reports and clinical characteristics of depression by conducting multiple and logistic regression analyses to determine whether personality uniquely predicted clinical characteristics and whether clinical characteristics uniquely predicted personality, after adjusting for depression severity. We also analyzed data at 6-month follow-up to determine whether age of onset and chronicity maintained their associations with personality. The study found that low levels of positive personality traits had unique associations with chronicity of depression, whereas elevated levels of negative personality traits had unique associations with an earlier onset of depression. Furthermore, associations were generally maintained over time, suggesting that associations between personality and these depression subtypes are stable.

Resting electroencephalogram asymmetry and posttraumatic stress disorder

The valence-arousal (W. Heller, 1993) and approach-withdrawal (R. J. Davidson, 1998a) models hypothesize that particular patterns of hemispheric brain activity are associated with specific motivational tendencies and psychopathologies. We tested several of these predictions in two groups-a posttraumatic stress disorder (PTSD) and a "supercontrol" group, selected to be maximally different from those with PTSD. Contrary to almost all hypotheses, individuals with PTSD did not differ from controls on resting electroencephalogram (EEG) asymmetry. Particular aspects of PTSD were also not related to EEG hemisphere differences. Our null findings are consistent with the few studies that have examined resting EEG asymmetries in PTSD and suggest that PTSD may be associated with different processes than psychopathologies previously examined in studies of hemispheric brain activity (e.g., major depressive disorder, panic disorder).

Dysthymic disorder and double depression: prediction of 10-year course trajectories and outcomes

We sought to identify baseline predictors of 10-year course trajectories and outcomes in patients with dysthymic disorder and double depression. Eighty-seven outpatients with early-onset (<21 years) dysthymic disorder, with or without superimposed major depression, were assessed five times at 30-month intervals for 10 years. Baseline evaluations included semi-structured diagnostic interviews for Axis I and II psychopathology and childhood adversity. Direct interview and family history data were collected on first-degree relatives. Follow-up assessments included the Longitudinal Follow-up Evaluation and Hamilton Depression Rating Scale. Using mixed effects growth curve models, univariate predictors of depression severity and functional impairment at 10-year outcome included older age, less education, concurrent anxiety disorder, greater familial loading for chronic depression, a history of a poorer maternal relationship in childhood, and a history of childhood sexual abuse. In addition, longer duration of dysthymic disorder also predicted greater impairment 10 years later. Predictors of a poorer trajectory of depressive symptoms over time included ethnicity and personality disorders; predictors of a poorer trajectory of social functioning included familial loading of chronic depression and quality of the childhood maternal relationship. Thus, demographic, clinical, family history, and early adversity variables all contribute to predicting the long-term trajectory and outcome of DD. These variables should be routinely assessed in clinical evaluations and can provide clinicians with valuable prognostic information.

Family study of subthreshold psychopathology in a community sample

BACKGROUND

There has been increasing interest in the validity and familial transmission of subthreshold psychiatric conditions and the relationship between subthreshold conditions and full syndrome (FS) disorders. However, most of these studies examined a single subthreshold condition and thus fail to take into account the high co-morbidity among subthreshold conditions and between subthreshold conditions and FS disorders.

METHOD

A family study of subthreshold psychiatric conditions was conducted with 739 community-drawn young adults and their 1744 relatives. We examined (1) whether relatives of probands with subthreshold major depression, bipolar disorder, anxiety disorders, alcohol use, substance use, and/or conduct disorder exhibited an increased rate of the corresponding (homotypic) FS disorder; (2) whether subthreshold disorders were associated with increased familial rates of other (heterotypic) FS disorders; (3) whether subthreshold and FS conditions are associated with similar familial liabilities; and (4) whether these homotypic and heterotypic associations persisted after controlling for co-morbidity.

RESULTS

Significant homotypic associations were observed for subthreshold anxiety, alcohol, conduct, and a trend was observed for major depression. Only the homotypic association for alcohol and conduct remained after controlling for co-morbid subthreshold and FS conditions. Many heterotypic associations were observed and most remained after controlling for co-morbidity.

CONCLUSIONS

It is important to broaden the study of subthreshold psychopathology to multiple disorders. In particular cases, controlling for co-morbidity with other subthreshold and FS conditions altered the patterns of familial aggregation. Etiological processes that are common to particular disorders and subthreshold conditions are discussed.

Hemispatial PCA dissociates temporal from parietal ERP generator patterns: CSD components in healthy adults and depressed patients during a dichotic oddball task

Event-related potentials (31-channel ERPs) were recorded from 38 depressed, unmedicated outpatients and 26 healthy adults (all right-handed) in tonal and phonetic oddball tasks developed to exploit the perceptual challenge of a dichotic stimulation. Tonal nontargets were pairs of complex tones (corresponding to musical notes G and B above middle C) presented simultaneously to each ear (L/R) in an alternating series (G/B or B/G; 2-s fixed SOA). A target tone (note A) replaced one of the pair on 20% of the trials (A/B, G/A, B/A, A/G). Phonetic nontargets were L/R pairs of syllables (/ba/, /da/) with a short voice onset time (VOT), and targets contained a syllable (/ta/) with a long VOT. Subjects responded with a left or right button press to targets (counterbalanced across blocks). Target detection was poorer in patients than controls and for tones than syllables. Reference-free current source densities (CSDs; spherical spline Laplacian) derived from ERP waveforms were simplified and measured using temporal, covariance-based PCA followed by unrestricted Varimax rotation. Target-related N2 sinks and mid-parietal P3 sources were represented by CSD factors peaking at 245 and 440 ms. The P3 source topography included a secondary, left-lateralized temporal lobe maximum for both targets and nontargets. However, a subsequent hemispheric spatiotemporal PCA disentangled temporal lobe N1 and P3 sources as distinct factors. P3 sources were reduced in patients compared with controls, even after using performance as a covariate. Results are consistent with prior reports of P3 reduction in depression and implicate distinct parietal and temporal generators of P3 when using a dichotic oddball paradigm.

Reward sensitivity in depression: A biobehavioral study

The approach-withdrawal model posits 2 neural systems of motivation and emotion and hypothesizes that these systems are responsible for individual differences in emotional reactivity, or affective styles. The model also proposes that depression is characterized by a deficit in reward-seeking behavior (i.e., approach motivation) and is associated with a relative decrease in left frontal brain activity. The authors tested aspects of this model by comparing the electroencephalogram alpha power of depressed and nondepressed individuals during a task that manipulated approach motivation. The study found that control participants and individuals with late-onset depression exhibited the hypothesized increase in left frontal activity during the approach task but individuals with early-onset depression did not. This suggests that early-onset depression may be associated with a deficit in the hypothesized approach motivation system.

Ten-year prospective follow-up study of the naturalistic course of dysthymic disorder and double depression

OBJECTIVE

The purpose of this study was to describe the 10-year course and outcome of dysthymic disorder.

METHOD

The authors conducted a naturalistic, prospective, longitudinal follow-up of 97 adults with early-onset dysthymic disorder and 45 adults with nonchronic major depressive disorder selected from consecutive admissions to several outpatient facilities. Follow-up data were obtained for 90% of the cohort. Assessments were conducted at baseline, 30, 60, 90, and 120 months. Measures included the Longitudinal Interval Follow-Up Evaluation and the Hamilton Depression Rating Scale.

RESULTS

The Kaplan-Meier estimated recovery rate from dysthymic disorder was 73.9%, with a median time to recovery of 52 months. Among patients who recovered, the estimated risk of relapse into another period of chronic depression was 71.4%. Chronic depressive relapses took a variety of forms and were not limited to dysthymia. Nonetheless, the distinction between chronic and nonchronic forms of depression was relatively stable over the follow-up period. Mixed-effects models indicated that patients with dysthymic disorder experienced a significantly slower rate of improvement in symptoms over time and exhibited significantly greater depression at the 10-year point, compared to patients with nonchronic major depression.

CONCLUSIONS

Dysthymic disorder has a protracted course and is associated with a high risk of relapse. The nature of chronic depressive episodes varies over time within individuals, indicating that the various manifestations of chronic depression in DSM-IV do not represent distinct disorders. However, the distinction between chronic and nonchronic forms of depression is relatively stable and may provide a useful basis for subtyping in genetic and neurobiological research.

Behavioral activation system deficits predict the six-month course of depression

BACKGROUND

Behavioral activation system (BAS) deficits are hypothesized to increase risk for depression. This study tested the hypothesis that BAS deficits, measured with both self-report and electrophysiological methods, would predict the six-month course of depression.

METHODS

67 participants with major depressive disorder (MDD) with or without pre-existing dysthymia were assessed at baseline with Carver and White's [Carver, C.S., White, T.L., 1994. Behavioral inhibition, behavioral activation, and affective responses to impending reward and punishment: the BIS/BAS scales. J. Pers. Soc. Psychol. 67, 319-333.] BIS/BAS scales and resting EEG. The week-by-week course of their depressive symptoms was assessed six months later with the Longitudinal Interval Follow-up Evaluation (LIFE).

RESULTS

Baseline self-reported BAS sensitivity predicted depression diagnosis (MDD or dysthymia) at follow-up, number of MDD symptoms at follow-up, average weekly level of depression, and time to recovery. These effects persisted after controlling for baseline clinical variables associated with a worse course. Baseline resting EEG alpha asymmetry did not significantly predict the course of depression.

LIMITATIONS

Although BAS sensitivity predicted the subsequent course of depression, we cannot determine whether it played a causal role in maintaining depression.

CONCLUSIONS

Lower self-reported BAS sensitivity predicts a worse course of depression but EEG asymmetries do not.