Nondepressed Individuals Research Articles

The temporal dynamics of cortisol and affective states in depressed and non-depressed individuals

ObjectivesCortisol levels have been related to mood disorders at the group level, but not much is known about how cortisol relates to affective states within individuals over time. We examined the temporal dynamics of cortisol and affective states in depressed and non-depressed individuals in daily life. Specifically, we addressed the direction and timing of the effects, as well as individual differences. MethodsThirty depressed and non-depressed participants (aged 20–50 years) filled out questionnaires regarding their affect and sampled saliva three times a day for 30 days in their natural environment. They were pair-matched on age, gender, smoking behavior and body mass index. The multivariate time series (T=90) of every participant were analyzed using vector autoregressive (VAR) modeling to assess lagged effects of cortisol on affect, and vice versa. Contemporaneous effects were assessed using the residuals of the VAR models. Impulse response function analysis was used to examine the timing of effects. ResultsFor 29 out of 30 participants, a VAR model could be constructed. A significant relationship between cortisol and positive or negative affect was found for the majority of the participants, but the direction, sign, and timing of the relationship varied among individuals. ConclusionThis approach proves to be a valuable addition to traditional group designs, because our results showed that daily life fluctuations in cortisol can influence affective states, and vice versa, but not in all individuals and in varying ways. Future studies may examine whether these individual differences relate to susceptibility for or progression of mood disorders.

Association of CRTC1 polymorphisms with obesity markers in subjects from the general population with lifetime depression

BackgroundPsychiatric disorders have been hypothesized to share common etiological pathways with obesity, suggesting related neurobiological bases. We aimed to examine whether CRTC1 polymorphisms were associated with major depressive disorder (MDD) and to test the association of these polymorphisms with obesity markers in several large case-control samples with MDD. MethodsThe association between CRTC1 polymorphisms and MDD was investigated in three case-control samples with MDD (PsyCoLaus n1=3,362, Radiant n2=3,148 and NESDA/NTR n3=4,663). The effect of CRTC1 polymorphisms on obesity markers was then explored. ResultsCRTC1 polymorphisms were not associated with MDD in the three samples. CRTC1 rs6510997C>T was significantly associated with fat mass in the PsyCoLaus study. In fact, a protective effect of this polymorphism was found in MDD cases (n=1,434, β=−1.32%, 95% CI −2.07 to −0.57, p<0.001), but not in controls. In the Radiant study, CRTC1 polymorphisms were associated with BMI, exclusively in individuals with MDD (n=2,138, β=−0.75kg/m2, 95% CI −1.30 to −0.21, p=0.007), while no association with BMI was found in the NESDA/NTR study. LimitationsEstimated fat mass using bioimpedance that capture more accurately adiposity was only present in the PsyCoLaus sample. ConclusionsCRTC1 polymorphisms seem to play a role with obesity markers in individuals with MDD rather than non-depressive individuals. Therefore, the weak association previously reported in the population-based samples was driven by cases diagnosed with lifetime MDD. However, CRTC1 seems not to be implicated directly in the development of psychiatric diseases.

Prefrontal Electrical Stimulation in Non-depressed Reduces Levels of Reported Negative Affects from Daily Stressors.

Negative emotional responses to the daily life stresses have cumulative effects which, in turn, impose wide-ranging negative constraints on emotional well being and neurocognitive performance (Kalueff and Nutt, 2007; Nadler et al., 2010; Charles et al., 2013). Crucial cognitive functions such as memory and problem solving, as well more short term emotional responses (e.g., anticipation of- and response to- monetary rewards or losses) are influenced by mood. The negative impact of these behavioral responses is felt at the individual level, but it also imposes major economic burden on modern healthcare systems. Although much research has been undertaken to understand the underlying mechanisms of depressed mood and design efficient treatment pathways, comparatively little was done to characterize mood modulations that remain within the boundaries of a healthy mental functioning. In one placebo-controlled experiment, we applied daily prefrontal transcranial Direct Current Stimulation (tDCS) at five points in time, and found reliable improvements on self-reported mood evaluation. Using a new team of experimenters, we replicated this finding in an independent double-blinded placebo-controlled experiment and showed that stimulation over a shorter period of time (3 days) is sufficient to create detectable mood improvements. Taken together, our data show that repeated bilateral prefrontal tDCS can reduce psychological distress in non-depressed individuals.

Bidirectional associations between rheumatoid arthritis and depression: a nationwide longitudinal study.

Rheumatoid arthritis (RA) and depression may be associated with each other pathophysiologically, but few studies have been conducted on the interplay between these two diseases using longitudinal measurement. Therefore, we used the National Health Insurance Research Database of Taiwan to investigate the bidirectional associations between RA and depression. One cohort was included to analyze RA predicting the onset of depression and a second cohort for analysis of depression predicting RA. A sex- and age-matched control group was included for both. The incidence of depression in RA subjects was higher than in non-RA subjects [15.69 vs. 8.95 per 1,000 person-years (PYs)], with an adjusted hazard ratios (HRs) of 1.69 [95% confidence interval (CI), 1.51–1.87]. The incidence of RA was higher in depressed than non-depressed individuals (2.07 vs. 1.21 per 1,000 PYs), with an adjusted HRs of 1.65 (95% CI, 1.41–1.77). This population-based cohort study suggested strong bidirectional relationships between RA and depression. Healthcare providers are recommended to facilitate the implementation of more effective therapeutic interventions to achieve favorable prognosis, especially for those with new-onset or younger cases.

Impact of physical exercise on catechol-O-methyltransferase activity in depressive patients: A preliminary communication

BackgroundCatechol-O-methyltransferase (COMT) is a catabolic enzyme involved in the degradation of bioactive molecules including the neurotransmitters epinephrine, norepinephrine, and dopamine. Higher COMT activity in depressive patients in comparison to non-depressed individuals has been reported. The effect of aerobic exercise on depressive patients has been studied and a number of researchers and clinicians believe it to be effective in the treatment of depression and to be involved in several molecular underlying mechanisms. However, the effect of physical exercise on this enzyme activity is unknown, and it remains to be elucidated if chronic exercise changes COMT activity. This randomized control trial evaluates the effects of chronic exercise on peripheral COMT (S-COMT) activity in women with depressive disorder. MethodsFourteen women (aged: 51.4±10.5 years) diagnosed with depression (according to International Classification of Diseases-10) were randomized to one of two groups: pharmacotherapy plus physical exercise (n=7) or only pharmacotherapy (n=7). The aerobic exercise program was supervised, lasting between 45–50min/session, three times/week for 16 weeks. Erythrocyte soluble COMT were assessed prior to and after the exercise program. ResultsExercise group when compared to a control group presented a significant decrease (p=0.02, r=−0.535) in S-COMT activity between baseline and post-intervention. LimitationsThese data are preliminary outcomes from a small sample and should be replicated. ConclusionsChronic exercise therapy combined with pharmacotherapy leads to significant decrease in S-COMT activity. Our results provide evidence that exercise interferes with S-COMT activity, a molecular mechanism involved in depression.

The Relationship between Autobiographical Self-Focus and Memory Specificity/Overgenerality: Differences between Individuals with and without a Diagnosis of Depression

Research has revealed that clinical depression is related to reduced specificity and/or overgenerality in autobiographical memory. We set out to investigate this relationship by comparing depressed (n = 40) and non-depressed (n = 40) individuals not only in terms of autobiographical memory specificity/generality, but also in terms of narrative structure. Specificity was assessed with the Autobiographical Memory Test (AMT; Williams &amp; Broadbent, 1986) and participants also provided open-ended memories, which were analyzed for autobiographical cognitive complexity (Woike, 1994). Narrative differentiation, as an indicator of self-focus, was negatively related to specificity and positively to overgenerality of particularly negative autobiographical memories – but only in the depressed sample. Relationships were significantly different among non-depressed individuals. Results are discussed in the context of the relation between specificity/overgenerality and self-focus.

Evaluation of the Consonant Vowel Consonant (CVC) Test as an Assessment and Screening Instrument for Mild Cognitive Impairment

&lt;p&gt;Objective: Traditional word learning tasks have been criticised for being affected by ceiling effects. The Consonant Vowel Consonant (CVC) test is a non-word verbal learning task designed to be more difficult and therefore have a lower risk of ceiling effects.&lt;/p&gt;&lt;p&gt;Method: The current study examines the psychometric properties of the CVC in 404 middle-aged persons and evaluates it as a screening instrument for mild cognitive impairment by comparing it to the Montreal Cognitive Assessment (MoCA). Differences between currently depressed and non-depressed participants were also examined.&lt;/p&gt;&lt;p&gt;Results: CVC characteristics are similar to traditional verbal memory tasks but with reduced likelihood of a ceiling effect. Using the standard cut-off on the MoCA as an indication of mild cognitive impairment, the CVC performed only moderately well in predicting this. Depressed participants scored significantly lower on the CVC compared with non-depressed individuals.&lt;/p&gt;&lt;p&gt;Conclusions: The CVC may be similar in psychometric properties to the traditional word learning tests but with a higher ceiling. Scores are lower in depression.&lt;/p&gt;

Tamsulosin Treatment Affecting Patient-reported Outcomes in Benign Prostatic Hyperplasia-associated Depressive Symptoms

To investigate the effect of tamsulosin on LUTS and depressive symptoms among depressed and nondepressed individuals previously diagnosed with benign prostatic hyperplasia. The study conducted from July 2013 to June 2014 included outpatient participants with benign prostatic hyperplasia presenting with lower urinary tract symptoms (LUTS). One tablet of tamsulosin (0.2 mg) was administered to patients daily. We divided participants with geriatric depression scale (GDS) scores of 0-17 into the nondepressive symptom group (group 1) and those with GDS scores of 18-30 into the depressive symptom group (group 2). At the first visit (V1), 4th week (V2), and 12th week (V3), the International Prostate Symptom Score (IPSS), quality of life (QoL), patient perception of bladder condition, overactive bladder syndrome symptom score, and GDS questionnaires were administered. IPSS (17.35 ± 7.11 vs 14.61 ± 6.04, P = .10) as well as GDS scores (20.97 ± 3.07 vs 8.84 ± 4.50, P < .01) were higher among those with depressive symptoms than those without, and difference between the two groups was not represented. After taking tamsulosin, on the V2 and V3, both groups had improved overactive bladder syndrome symptom scores, patient perception of bladder condition, IPSS, QoL, and GDS. Comparing the first visit with the V2 and V3, group 2 showed significant changes in GDS, but group 1 did not. Treatment with tamsulosin is associated with improved LUTS and decreased depressive symptoms, which could enhance QoL.

Serum Magnesium Status in Patients Subjects with Depression in the City of Yazd in Iran 2013-2014.

Depression is the most common mental disorder and involves many factors. The regulatory effects of magnesium on N-methyl-D-aspartate (NMDA) channels make it a factor in the treatment of depression. The present study investigated the level of serum magnesium in subjects diagnosed with depression in the city of Yazd in Iran. This cross-sectional study was done from January 2013 to January 2014 on 650 patients with depression who agreed to participate in this study. Diagnosis was made using the Beck Depression Inventory test (BDI-II); those scoring higher than 11 were sent to the medical school laboratory for further testing of serum magnesium levels. The mean age of the patients was 34.16 ± 9.12years. Of the 650 subjects, 195 were male (30%) and 455 were female (70%). The total mean serum magnesium was 2.1 ± 0.26mg/dl. The prevalence of hypomagnesemia 13.7%, hypermagnesemia 8.3%, and sub-optimal magnesium levels was 26.5%. Sub-optimal prevalence in women (28.1%) was higher than in men (26.2%). A significant relationship was observed between depression and serum magnesium level (p = 0.02). The results indicated that the prevalence of hypomagnesemia in subjects diagnosed with depression is high compared to non-depressed individuals. Moreover, there was a significant relationship between hypomagnesemia and intensity of depression that suggests a role for this element in the pathogenesis of the disorder. The high sub-optimal prevalence among women indicates that increased attention should be paid to this group.

Me, myself, and I: self-referent word use as an indicator of self-focused attention in relation to depression and anxiety.

Self-focused attention (SFA) is considered a cognitive bias that is closely related to depression. However, it is not yet well understood whether it represents a disorder-specific or a trans-diagnostic phenomenon and which role the valence of a given context is playing in this regard. Computerized quantitative text-analysis offers an integrative psycho-linguistic approach that may help to provide new insights into these complex relationships. The relative frequency of first-person singular pronouns in natural language is regarded as an objective, linguistic marker of SFA. Here we present two studies that examined the associations between SFA and symptoms of depression and anxiety in two different contexts (positive vs. negative valence), as well as the convergence between pronoun-use and self-reported aspects of SFA. In the first study, we found that the use of first-person singular pronouns during negative but not during positive memory recall was positively related to symptoms of depression and anxiety in patients with anorexia nervosa with varying levels of co-morbid depression and anxiety. In the second study, we found the same pattern of results in non-depressed individuals. In addition, use of first-person singular pronouns during negative memory recall was positively related to brooding (i.e., the assumed maladaptive sub-component of rumination) but not to reflection. These findings could not be replicated in two samples of depressed patients. However, non-chronically depressed patients used more first-person singular pronouns than healthy controls, irrespective of context. Taken together, the findings lend partial support to theoretical models that emphasize the effects of context on self-focus and consider SFA as a relevant trans-diagnostic phenomenon. In addition, the present findings point to the construct validity of pronoun-use as a linguistic marker of maladaptive self-focus.

Pain grade and sleep disturbance in older adults: evaluation the role of pain, and stress for depressed and non-depressed individuals.

The aim of this paper was to assess the relationship between pain and sleep in older adults taking depression, stress, and medical comorbidities into account. A cross-sectional analysis was performed using Einstein Aging Study, a community-based cohort study of adults aged 70 years and older. Ratings of pain intensity and interference from the Medical Outcomes Study (MOS) Short-Form 36 were used to assign individuals to low-pain versus high-pain severity. Sleep disturbance was assessed using the nine-item sleep problems index from the Medical Outcomes Study Sleep Scale. Other measures included the Geriatric Depression Scale and Perceived Stress Scale (PSS). Linear regression models were used to assess the association between pain grade and sleep disturbance adjusted for demographics, PSS, Geriatric Depression Scale, and other comorbidities. Five hundred sixty-two eligible participants with a mean age of 78.22 years (standard deviation = 5.43) were included; 64% were women. Pain grade [β = 5.40, 95% confidence interval (CI) 2.56-8.21, p < 0.001] was associated with sleep disturbance after adjusting for demographic variables. In models including pain grade (β = 3.08, 95% CI 0.32-5.85, p = 0.03) and PSS (β = 0.57, 95% CI 0.39-0.75, p < 0.001), both were associated with sleep disturbance, although the PSS attenuated the relationship between pain and sleep by 34%. Depression, when added to previous model, was also associated with sleep (β = 2.17, 95% CI 1.48-2.85, p < 0.001) and attenuated the relationship between pain (β = 2.41, 95% CI -0.25 to 5.08, p = 0.07) and sleep by 22%. Stratified for depression, we found that pain, stress, and other medical comorbidities were significantly associated with sleep disturbance in non-depressed individuals but not individuals with depression. Pain, stress, and medical comorbidities are associated with sleep disturbance, especially in non-depressed older adults.

Rumination and Self-destructive Thoughts in People with Depression

Increasing rates of suicide have peaked interest in how individuals with depression may view their environment differently and have abnormal thought processes compared to non-depressed individuals. In order to explore how depressive thought processes lead to completed suicide, this review of literature looks at research and theoretical explanations of rumination, self-destructive thoughts, and feelings of hopelessness. People with depression are more attentive to both their own and other people’s actions and have a strong desire for control. Rumination prevents effective problem solving and increases the duration of depressive symptoms. Highly self-aware individuals often attend to discrepancies between the real self and who they wish to be, which causes distress and overthinking about negative aspects of problems while neglecting the development of solutions. Suicide is one method of escaping the self when these discrepancies become salient and continual failure also leads to feelings of hopelessness. Positive distraction such as getting involved in hobbies as well as the promotion of optimistic and hopeful thoughts may help depressive ruminators refrain from negative thoughts and may ultimately help prevent suicide.

Poorer Drinking Outcomes with Citalopram Treatment for Alcohol Dependence: A Randomized, Double-Blind, Placebo-Controlled Trial.

Previous research on the use of selective serotonin reuptake inhibitors (SSRIs) as a treatment for alcohol dependence has yielded mixed results. Depression has been shown to be a predictor of relapse and poor outcome following treatment, and it has been hypothesized that SSRIs would be beneficial in reducing drinking in depressed alcohol-dependent individuals. This randomized, double-blind, placebo-controlled trial was designed to test the effects of citalopram on treatment outcomes among alcohol-dependent individuals with and without depression. Two hundred and sixty-five patients meeting criteria for a DSM-IV diagnosis of alcohol abuse or dependence were randomly assigned to receive placebo or citalopram 20 mg per day for the first week, followed by 40 mg per day from weeks 2 through 12. All patients received a standard course of treatment consisting of weekly individual and group psychotherapy. Participants were reassessed at 12 weeks, including dropouts from both treatment groups to determine rates of abstinence, changes in alcohol use, addiction severity, depressive symptoms, and psychiatric status. Citalopram provided no advantage over placebo in terms of treatment outcomes, and for some measures, citalopram produced poorer outcomes. Patients in the citalopram group had a higher number of heavy drinking days throughout the trial, and smaller changes in frequency and amount of alcohol consumption at 12 weeks. There was no influence of depression severity on outcomes in either medication group. Survival analyses also indicated no differences between depressed and nondepressed patients in the citalopram group for time to first slip or relapse. A diagnosis of personality disorder was associated with poorer treatment responses overall, regardless of treatment condition. This trial does not support the use of citalopram in the treatment of alcohol dependence. The results suggest that the use of SSRIs among depressed and nondepressed alcohol-dependent individuals early in recovery, prior to the onset of abstinence, may be contraindicated.

Interaction of the 5-HTTLPR and childhood trauma influences memory bias in healthy individuals

The tendency to recall more negative and less positive information has been frequently related to the genetic susceptibility to depression. This memory bias may be associated with depression candidate genes especially in individuals who experienced stressful childhood events. The serotonin transporter gene, SLC6A4/5-HTT, regulates the reuptake of serotonin. The 5-HTTLPR polymorphism in the gene’s promoter region has a short (S) and a long (L) allele, of which L contains a further SNP (rs25531), resulting in a triallelic polymorphism: La, Lg, and S.Both S and Lg result in increased serotonin signaling (to simplify, we refer to both alleles as ‘S’), which in turn appears associated with depression vulnerability, specifically in individuals with stressful events.In non-depressed individuals (N=1083), we examined the interaction between the 5-HTTLPR genotype (LaLa, SLa, and SS) and stressful childhood events in association with explicit verbal memory bias (positive, negative). Two types of stressful childhood events were studied, namely childhood adverse events (e.g. parental loss) and interpersonal traumatic childhood events (e.g. abuse).Less positive memory bias was found for individuals with the SS genotype who had experienced interpersonal childhood traumatic events. No general association of genotype with memory bias was found, nor was there a significant interaction between genotype and childhood adverse events.Our results suggest that the depression-susceptibility genotype of the 5-HTTLPR is associated with depressive information processing styles when occurring in combination with traumatic childhood events. Tailoring treatment to specific risk profiles based on genetic susceptibility and childhood stress could be promising.

Long term sertraline effects on neural structures in depressed and nondepressed adult female nonhuman primates

BackgroundSelective serotonin reuptake inhibitors (SSRIs) are widely prescribed for mood and other disorders. However, their neural effects are difficult to study due to patient compliance and drug history variability, and rarely studied in those prescribed SSRIs for non-mood disorders. Here we evaluated SSRI effects on neural volumetrics in depressed and nondepressed monkeys. Methods42 socially-housed cynomolgus monkeys were randomized to treatment balanced on pretreatment depressive behavior and body weight. Monkeys were trained for oral administration of placebo or 20 mg/kg sertraline HCl daily for 18 months and depressive and anxious behavior recorded. Volumes of neural regions of interest in depression were measured in magnetic resonance images and analyzed by 2 (depressed, nondepressed) × 2 (placebo, sertraline) ANOVA. ResultsSertraline reduced anxiety (p = 0.04) but not depressive behavior (p = 0.43). Left Brodmann's Area (BA) 32 was smaller in depressed than nondepressed monkeys (main effect of depression: p < 0.05). Sertraline and depression status interacted to affect volumes of left Anterior Cingulate Cortex (ACC), left BA24, right hippocampus (HC), and right anterior HC (sertraline × depression interactions: all p's < 0.05). In the Placebo group, depressed monkeys had smaller right anterior HC and left ACC than nondepressed monkeys. In nondepressed monkeys, sertraline reduced right HC volume, especially right anterior HC volume. In depressed monkeys sertraline increased left ACC volume. In nondepressed monkeys, sertraline reduced left BA24 volumes resulting in smaller BA24 volumes in nondepressed than sertraline-treated depressed monkeys. ConclusionsThese observations suggest that SSRIs may differentially affect neural structures in depressed and nondepressed individuals.

A randomized controlled trial to test the effect of multispecies probiotics on cognitive reactivity to sad mood.

Recent insights into the role of the human microbiota in cognitive and affective functioning have led to the hypothesis that probiotic supplementation may act as an adjuvant strategy to ameliorate or prevent depression. Heightened cognitive reactivity to normal, transient changes in sad mood is an established marker of vulnerability to depression and is considered an important target for interventions. The present study aimed to test if a multispecies probiotic containing Bifidobacterium bifidum W23, Bifidobacterium lactis W52, Lactobacillus acidophilus W37, Lactobacillus brevis W63, Lactobacillus casei W56, Lactobacillus salivarius W24, and Lactococcus lactis (W19 and W58) may reduce cognitive reactivity in non-depressed individuals. In a triple-blind, placebo-controlled, randomized, pre- and post-intervention assessment design, 20 healthy participants without current mood disorder received a 4-week probiotic food-supplement intervention with the multispecies probiotics, while 20 control participants received an inert placebo for the same period. In the pre- and post-intervention assessment, cognitive reactivity to sad mood was assessed using the revised Leiden index of depression sensitivity scale. Compared to participants who received the placebo intervention, participants who received the 4-week multispecies probiotics intervention showed a significantly reduced overall cognitive reactivity to sad mood, which was largely accounted for by reduced rumination and aggressive thoughts. These results provide the first evidence that the intake of probiotics may help reduce negative thoughts associated with sad mood. Probiotics supplementation warrants further research as a potential preventive strategy for depression.

Prevalence and influencing factors of depressive symptoms among women of reproductive age in the rural areas of Hubei, China

ObjectivesDepression is one of the most common mental disorders and a major public health problem in the Chinese population, especially among women. The current study aims to understand prevalence of depression symptoms and provide detailed epidemiological factors associated with depression among reproductive women in rural areas which was paid less attention in previous surveys. Study designCross-sectional study. MethodsFace-to-face household interviews were conducted on 1058 women (age: 15–49 years) in rural areas from July 2012 to August 2012. Questionnaires were used to investigate the influencing factors of depression among women. Pearson's χ2, logistic regression analysis and structural equation modelling (SEM) were applied to analyze the related factors. ResultsThe prevalence of depression among women was 30.7% [95% confidence interval (CI): 27.9%–33.5%]. Compared with non-depressed individuals, those with depression were more likely to be short of social support [odd ratio (OR): 0.940, P < 0.001) and have no one to talk with (OR: 0.366, P < 0.001), to be dissatisfied with the house (OR: 2.673, P < 0.001) and economy (OR: 2.268, P < 0.01) of their family, and to have great pressure (OR: 2.099, P < 0.01), negative life events (OR: 1.485, P < 0.05) and physical diseases (OR: 1.364, P < 0.05). Pressure status, social support assessment, and socio-economic status were negatively related to depression (correlation coefficient: −0.57, −0.27 and 0.17). ConclusionsThe high prevalence of depression among reproductive women in rural areas is of particular concern. Factors associated with depression may assist health care administrations to identify and assess high-risk women and target strategies accordingly.

Natural history of excessive daytime sleepiness: role of obesity, weight loss, depression, and sleep propensity.

Excessive daytime sleepiness (EDS) is highly prevalent in the general population and is associated with occupational and public safety hazards. However, no study has examined the clinical and polysomnographic (PSG) predictors of the natural history of EDS. Representative longitudinal study. Sleep laboratory. From a random, general population sample of 1,741 individuals of the Penn State Adult Cohort, 1,395 were followed up after 7.5 years. Full medical evaluation and 1-night PSG at baseline and standardized telephone interview at follow-up. The incidence of EDS was 8.2%, while its persistence and remission were 38% and 62%, respectively. Obesity and weight gain were associated with the incidence and persistence of EDS, while weight loss was associated with its remission. Significant interactions between depression and PSG parameters on incident EDS showed that, in depressed individuals, incident EDS was associated with sleep disturbances, while in non-depressed individuals, incident EDS was associated with increased physiologic sleep propensity. Diabetes, allergy/ asthma, anemia, and sleep complaints also predicted the natural history of EDS. Obesity, a disorder of epidemic proportions, is a major risk factor for the incidence and chronicity of EDS, while weight loss is associated with its remission. Interestingly, objective sleep disturbances predict incident EDS in depressed individuals, whereas physiologic sleep propensity predicts incident EDS in those without depression. Weight management and treatment of depression and sleep disorders should be part of our public health policies.

Memory bias training by means of the emotional short-term memory task

Abstract According to major cognitive theories of emotional disorders cognitive biases are partly responsible for their onset and maintenance. The direct test of this assumption is possible only if experimental method capable of altering a given form of cognitive bias is available. The purpose of the study was to examine the effectiveness of a novel implicit memory bias training procedure based on the emotional version of the classical Sternberg’s short-term memory task with negative, neutral and positive words. 108 participants, who completed the PANAS and the CES-D questionnaires, were randomly assigned to the control group (n = 33), the No-Negative group (n = 36), in which the target words in the Sternberg’s task were either positive or neutral but never negative or the Negative-New group (n = 39) in which the negative target words in the modified Sternberg’s task were always new. This training was followed by the recollection stage. Only one of the training protocols resulted in significant effects at the recall stage - individuals in the No-Negative group recalled more positive words and fewer negative words than those in the control group. These results show that it may be possible to experimentally induce memory bias characteristic of non-depressed individuals.

Machine learning approaches for integrating clinical and imaging features in late-life depression classification and response prediction.

Currently, depression diagnosis relies primarily on behavioral symptoms and signs, and treatment is guided by trial and error instead of evaluating associated underlying brain characteristics. Unlike past studies, we attempted to estimate accurate prediction models for late-life depression diagnosis and treatment response using multiple machine learning methods with inputs of multi-modal imaging and non-imaging whole brain and network-based features. Late-life depression patients (medicated post-recruitment) (n = 33) and older non-depressed individuals (n = 35) were recruited. Their demographics and cognitive ability scores were recorded, and brain characteristics were acquired using multi-modal magnetic resonance imaging pretreatment. Linear and nonlinear learning methods were tested for estimating accurate prediction models. A learning method called alternating decision trees estimated the most accurate prediction models for late-life depression diagnosis (87.27% accuracy) and treatment response (89.47% accuracy). The diagnosis model included measures of age, Mini-mental state examination score, and structural imaging (e.g. whole brain atrophy and global white mater hyperintensity burden). The treatment response model included measures of structural and functional connectivity. Combinations of multi-modal imaging and/or non-imaging measures may help better predict late-life depression diagnosis and treatment response. As a preliminary observation, we speculate that the results may also suggest that different underlying brain characteristics defined by multi-modal imaging measures-rather than region-based differences-are associated with depression versus depression recovery because to our knowledge this is the first depression study to accurately predict both using the same approach. These findings may help better understand late-life depression and identify preliminary steps toward personalized late-life depression treatment.