Executive functioning and verbal memory in young patients with unipolar depression and schizophrenia

Although neuropsychological studies have consistently reported executive deficits in schizophrenia, studies of executive functions in depression have produced equivocal results. The aim of this study was to examine the profile and the specificity of the executive impairment and its association with memory performance in young patients with unipolar depression. We compared patients with depression to normal control subjects and schizophrenics. Twenty young inpatients with unipolar depression, 14 schizophrenics and 20 age-, education- and IQ-matched control subjects were assessed with a neuropsychological battery including: (1) verbal memory task; (2) frontal tasks (WCST, Cognitive Estimate, Verbal fluency, verbal and visuo-spatial span) and a new complex sorting test (Delis test). Depressed patients and schizophrenics exhibited executive deficits. Unlike schizophrenics, depressed patients did not show memory impairment. Deficits in several 'higher-level' functions combined to produce executive impairments in patients with depression including complex integration for concept formation, spontaneous cognitive flexibility and initiation ability. Impaired functions in schizophrenia and in depressed patients were similar but were differently related to clinical variables. The pattern of memory failure in our schizophrenics is believed to reflect retrieval and encoding deficits. Our findings highlight the heterogeneity of skills grouped under the term 'executive functions' that are vulnerable in depression or schizophrenia.     

Social functioning in depression: a review

OBJECTIVE: This article reviews the available data on social functioning in depression and provides clinical guidelines and opinion on this important and expanding field. DATA SOURCES: A MEDLINE search was conducted to identify all English-language articles (1988-1999) using the search terms depression and social functioning, depression and social adjustment, depression and psychosocial functioning, and social functioning and antidepressant. Further articles were obtained from the bibliographies of relevant articles. DATA SYNTHESIS: Depressive disorders are frequently associated with significant and pervasive impairments in social functioning, often substantially worse than those experienced by patients with other chronic medical conditions. The enormous personal, social, and economic impact of depression, due in no small part to the associated impairments in social functioning, is often underappreciated. Both pharmacologic and psychotherapeutic approaches can improve social impairments, although there is a lack of extended, randomized controlled trials in this area using consistent assessment criteria. CONCLUSION: Despite this lack, it is becoming clear that not all treatments are equally effective in relieving the impaired social functioning associated with depressive disorders. Furthermore, efficacy in relieving the core symptoms of depression does not necessarily guarantee efficacy in relieving impaired social functioning.     

Executive deficits in elderly patients with major unipolar depression

Several studies have evaluated executive function in depressed patients, and the results vary from significant impairment relative to controls to virtually intact performances. To better comprehend executive impairment in elderly patients with major unipolar depression, the performance of 21 elderly depressed patients was compared with that of 19 elderly normal controls on executive tasks. The relationships between memory deficits and depression severity and between memory deficits and executive dysfunction were also examined. Depressed patients' performance was significantly worse than that of controls on almost all executive tasks. Their score for logical memory was significantly correlated with that for several executive tasks. Executive performance was also correlated with depression severity. Unipolar depressed patients present executive deficits. Memory failure in these patients may reflect impairment in retrieval processes, which in turn depends on executive function. Executive deficits are associated with depression severity. These results may be useful in the differential diagnosis between depression and early Alzheimer's disease.     

Executive functions in unipolar depression before and after electroconvulsive therapy

A neuropsychological investigation of executive functions in patients with unipolar depression was conducted. Ten patients with unipolar depression were tested before, 48 hours after, and 3 months after ECT. Control subjects were tested at similar intervals. Measures included 10 executive and related tasks (20 variables) on which frontal lobe lesion patients have been previously shown to be differentially impaired, and 1 "nonexecutive" task. Patients were significantly inferior to controls on 9 of the executive and related variables before treatment and performed slightly worse 48 hours after treatment. Significant improvement after 3 months was absent. Depressed patients were not impaired on the "nonexecutive" task.     

Executive function improvement upon remission of recurrent unipolar depression

The aim of the study was to investigate the improvement of executive function measures upon recovery from unipolar depression. Thirty patients who suffered from recurrent major unipolar depression were retested with regard to their executive function approximately two years after an initial baseline examination. At baseline, patients were depressed (average 17-item HAM-D score 21.8), at retesting they were partially or totally recovered (average HAM-D score 8.2). There was a significant positive association between improvement on the HAM-D and improvement of executive function. In those with complete recovery, overall executive function and most examined executive function measures were no longer different from the baseline performance of healthy controls (with the possible exception of semantic fluency and Stroop Colour-word). In conclusion, recovery from major unipolar depression was accompanied by a recovery of many aspects of executive function to a normal level. Our findings support previous studies that have shown that neuropsychological impairment associated with long-standing depressive symptomatology is reversible (i. e. state-related) in recurrent unipolar depression.     

Psychosocial and neurocognitive functioning in unipolar and bipolar depression: a 12-month prospective study

Previous studies have revealed psychosocial and cognitive impairments in patients during unipolar and bipolar depression, which persist even in subsyndromal and euthymic states. Currently, little is known about the nature and the extent of psychosocial and cognitive deficits during depression. The aim of the present study was to characterize psychosocial and cognitive profiles among unipolar (MDD) and bipolar (BD) patients during a major depressive episode and to compare the profiles of the patient groups. Depressed patients with MDD (n=13) and BD (n=11) were followed over a period of 12 months. Clinical, psychosocial and neuropsychological assessments were conducted at baseline and at 6-week, 4-month, 8-month and 12-month follow-ups. In the case of severe mood disorders, psychosocial and neurocognitive functioning seem similar among MDD and BD patients during a depressive episode. All MDD and BD patients had global psychosocial dysfunction, characterized by occupational and relational impairments. Furthermore, the neurocognitive profile was heterogeneous with regard to the nature and extent of cognitive deficits but attentional processes were frequently compromised. After 1 year of treatment, occupational and relational impairments, as well as neurocognitive dysfunction, persisted sufficiently to alter daily functioning.     

Executive functioning in offspring at risk for depression and anxiety

Background: Executive functioning deficits (EFDs) have been found in adults with major depression and some anxiety disorders, yet it is unknown whether these deficits predate onset of disorder, or whether they reflect acute symptoms. Studies of at‐risk offspring can shed light on this question by examining whether EFDs characterize children at high risk for depression and anxiety who are not yet symptomatic. Methods: This study examined neuropsychological functioning in a sample of 147 children, ages 6–17 years (M age=9.16, SD=1.82), of parents with major depression (MDD) and/or panic disorder (PD) and of controls with neither disorder. Children were assessed via structured diagnostic interviews and neuropsychological measures. Results: Although parental MDD and PD were not associated with neuropsychological impairments, presence of current offspring MDD was associated with poorer performance on several executive functioning and processing speed measures. Children with current generalized anxiety showed poorer verbal memory, whereas children with social phobia had more omissions on a continuous performance task. Conclusions: Findings suggest that EFDs do not serve as trait markers for developing anxiety or depression but appear to be symptomatic of current disorder. Depression and Anxiety, 2009. © 2009 Wiley‐Liss, Inc.     

Executive functions and updating of the contents of working memory in unipolar depression

Background: Depression is characterized by cognitive impairments, including executive dysfunctions. These executive deficits could reflect impairments of more basic executive processes, such as updating, set shifting and inhibition. While shifting and inhibition impairments are often reported, studies on depression have been somewhat obscure about specific deficits of the updating process. The main goal of that study was to assess the updating process in young in-patients with depression.

Methods: We used a verbal n-back task to assess updating process. Load and mental manipulation within working memory (WM) were incremented by using three different levels of complexity (1,2,3-back). Neuropsychological tests and an attentional task (0-back) were also administered to subjects. Twenty-two individuals meeting DSM-IV criteria for Major Unipolar Depression and 22 healthy control subjects, matched on age, verbal IQ and education, were included in the study.

Results: Subjects with depression showed significant deficits at the n-back task compared to control subjects. They were normal in tasks assessing the short-term maintenance in WM and attention. This suggests that depressed patients exhibit impairment in the updating process. Depressed patients also showed set shifting and inhibition deficits. Only the n-back task was correlated with the number of hospitalizations and the longitudinal course of the illness.

Conclusions: Our results suggest that young depressed in-patients have widespread executive dysfunctions, including updating, shifting and inhibition processes. We also found a correlation between a longitudinal measure of depression severity and an updating task performance. We suggest that using multiple executive tasks gives the opportunity to distinguish the specific influence of various executive processes on clinical dimensions in depression.     

Long-term social functioning after depression treated by psychiatrists: a review

OBJECTIVES: Numerous long-term studies of depression in psychiatric settings have shown a poor clinical outcome but little emphasis has been placed on psychosocial or functional outcome in studies to date. This article reviews published data on long-term social functioning after depression and considers why psychosocial recovery appears delayed compared with clinical recovery. METHODS: Searches were carried out of the databases MEDLINE, PSYCHLIT and EMBASE for articles published from 1980 using keywords relating to social and functional outcomes of unipolar and bipolar depression. Review articles and relevant textbooks were also searched. RESULTS: The few outcome studies published have described long-term functional impairment in the majority of patients but have been limited by methodological shortcomings. Psychosocial impairment tends to persist even after clinical remission from depression. Residual symptomatology after remission from depression may lead to enduring psychosocial impairment, as may subtle neurocognitive deficits. Axis I and II comorbidities predict a poor psychosocial outcome, but episodes of depression do not appear to lead to personality 'scarring'. CONCLUSIONS: Future outcome studies need to focus on longitudinal social functioning. Full functional recovery after an episode of depression should be the goal of treatment as enduring residual symptoms lead to long-term psychosocial impairment.     

Discontinuation of lithium augmentation in geriatric patients with unipolar depression: a systematic review.

OBJECTIVE: Lithium is an augmentation strategy for unipolar depression in geriatric populations. This review outlines the evidence in the literature regarding risk of relapse when lithium is discontinued in geriatric patients. METHOD: Articles were selected based on selection criteria for relevance and design quality (original studies, French or English, patients older than 65 years, patients with an episode of major depressive disorder, meeting DSM-III or greater criteria, and patients who had been successfully treated to remission with lithium augmentation of an antidepressant, then withdrawn from lithium augmentation treatment). RESULTS: Three articles were found. Overall rate of relapse could not be clearly established but a rate of 50% relapse over about 6 months follow-up could be surmised from the study results. CONCLUSIONS: There is a risk of relapse in elderly patients whose lithium augmentation treatment for unipolar depression is discontinued. More studies with a randomized control trial design are required to provide more definitive information on this topic.     

Executive functioning in anorexia nervosa: exploration of the role of obsessionality, depression and starvation

Cognitive deficits related to executive functioning have been previously identified in anorexia nervosa (AN). Currently, there is limited knowledge about the degree to which other variables related to AN or executive function may influence the observed relationships. The present study examined three groups of participants, women with AN (n = 22), and two control groups: women who were high in obessionality (n = 20) and women who were low in obsessionality (n = 21). Women reporting disordered eating over the previous 4 weeks were screened out of the control groups. Executive function was measured using the Wisconsin card sorting test (WCST) and the uses of common objects test (UCOT). In addition, depression, obsessionality and body mass index were measured. Initial analyses showed no significant differences between the groups on executive function, but moderate effect sizes were obtained for performance on UCOT total perseverations and WCST total trials. When controlling for either depression or obsessionality, the group differences on the UCOT total perseverations became significant and in the case of depression attained a large effect size. Both the AN and high obsessional groups showed significantly more perseverations than the low obsessional group. Depression appeared to suppress variance that was irrelevant to the prediction of perseverance thus enhancing the importance of group membership. It is recommended that variables strongly associated with AN be investigated in future research as this may clarify the relationship between AN and executive function.     

Early recurrence in unipolar depression

While some advances have occurred in the maintenance treatment of unipolar depression, empirical data on recurrences of illness following the discontinuation of medication are sparse. We examined survival time during the first 18 months after discontinuation of medication in 74 patients with recurrent unipolar depression. Although demographic characteristics, clinical characteristics, and pharmacologic treatment variables failed to predict time to recurrence, continued interpersonal psychotherapy was significantly related to longer survival time.     

Combination pharmacotherapy in unipolar depression

It is estimated that between 60 and 80% of those with major depressive disorder do not achieve full symptomatic remission from first-line antidepressant monotherapy. Residual depressive symptoms substantially impair quality of life and add to the risk of recurrence. It is now clear that depression would benefit from more vigorous treatment, in order to ameliorate its disease burden. While there are established algorithms in situations of treatment resistance, the use of combination pharmacotherapy in unipolar depression is a relatively under-investigated area of treatment and may be an effective and tolerable strategy that maximizes the available resources. This paper reviews the current evidence for combination pharmacotherapy in unipolar depression and discusses its clinical applications.     

Relapse in recurrent unipolar depression

Treatment of the acute phase of recurrent depression has become both routine and successful in the last decade, but the rates of relapse and recurrence remain a problem. In this study a combined psychopharmacologic/psychotherapeutic approach to the acute and continuation treatment of unipolar depressed patients was used. For 59 patients who completed the continuation phase of treatment, the relapse rate after 8 weeks of recovery was 8.5%. Since other recent studies of recurrent depression have reported relapse rates of 15%-22%, these results suggest that there are advantages in combined treatment.