Depressed Participants Research Articles

A double-blind pilot study of transcranial ultrasound (TUS) as a five-day intervention: TUS mitigates worry among depressed participants

Transcranial ultrasound (TUS) provides a noninvasive neuromodulation method that has greater spatial precision than existing methods. The present study examined TUS, for the first time, as a potential depression intervention. Twenty-four college students with mild to moderate depression were randomly assigned to an Active TUS Condition or Placebo TUS (no power administered). Participants completed five TUS sessions within seven days. Although depression scores did not change differentially for TUS/Placebo, trait worry decreased in the Active TUS Condition and increased in the Placebo condition. Additionally, those in TUS Active Condition had an increase in global affect over the course of the study, whereas those in the Placebo Condition did not. These results have significant implications for the potential utility of TUS as an intervention for anxiety disorders or worry-related psychopathology, warranting future investigation of the impact of TUS in a larger sample.

Highly variable suicidal ideation: a phenotypic marker for stress induced suicide risk.

Suicidal behavior (SB) can be impulsive or methodical; violent or not; follow a stressor or no obvious precipitant. This study tested whether childhood trauma, affective lability, and aggressive and impulsive traits predicted greater SI variability. We also assessed whether affective lability, aggressive or impulsive traits explain childhood trauma’s effects on SI variability and whether those with highly variable SI respond to stressful events with increases in SI. Finally, we assessed variable SI’s trajectory over 2 years. Depressed participants (n=51) had ecological momentary assessments (EMA) over 7 days at baseline, 3, 6, 12, 18, and 24-months. SI variability was assessed using the square Root of the Mean Square of Successive Deviations. Mixed Effects Models were fit as appropriate. Childhood trauma was associated with subsequent aggression. Physical abuse predicted both aggression and affective lability as well as SI variability, but not impulsivity. In two-predictor models, physical abuse’s effect on SI variability was no longer significant, when controlling for the effect of higher aggression and impulsivity. Those with high SI variability exhibited greater increases in SI after stressors compared to those with less variability. We did not find that SI variability changed over time, suggesting it might be trait-like, at least over two-years. Variable SI predisposes to marked SI increases after stressful events and may be a trait increasing risk for impulsive SB, at least over 2 years.

Cognitive control over emotional information in current and remitted depression

Cognitive theories of depression propose that difficulty exerting cognitive control over emotional information may be involved in the development, maintenance, and/or recurrence of depression. This study evaluated depression-related biases in three cognitive control functions, namely inhibition, working memory updating, and set shifting. Currently depressed (n = 53), remitted depressed (n = 55), and non-clinical control (n = 51) participants completed computer-based paradigms designed to measure inhibition, working memory updating, and set shifting, respectively, involving emotional stimuli. As hypothesized, currently depressed participants exhibited biases in cognitive control over emotional information but did not exhibit broad impairments on a non-emotional measure of cognitive control. Specifically, currently depressed participants showed a reduced ability to inhibit the processing of negative distracting stimuli and to update working memory with emotional information, relative to control participants. Currently depressed participants also had greater difficulty shifting away from an emotion-relevant task set than from an emotion-irrelevant task set, whereas control participants did not show this bias. Remitted depressed participants did not demonstrate similar biases to currently depressed participants.

Self‐referential processing and emotion context insensitivity in major depressive disorder

We examined whether differential self-perception influences the salience of emotional stimuli in depressive disorders, using a perceptual matching task in which geometric shapes were arbitrarily assigned to the self and an unknown other. Participants associated shapes with personal labels (e.g. "self" or "other"). Each geometric shape additionally contained a happy, sad or neutral line drawing of a face. Participants then judged whether shape-label pairs were as originally shown or re-paired, whilst facial emotion was task-irrelevant. The results showed biased responses to self-relevant stimuli compared to other-relevant stimuli, regardless of facial emotion, for both control and depressed participants. This was reflected in sensitivity (d') and drift rate (v) measures, suggesting that self-bias and a bias towards emotion may reflect different underlying processes. We further computed bias scores by subtracting the "neutral" value of each measure (acting as baseline) from the "happy" and "sad" values of each measure, indexing an "emotional bias" (EB) score for "self" and "other" separately. Compared to control participants, depressed participants exhibited reduced "happy" and "sad" emotional biases, regardless of the self-relevance of stimuli. This finding indicates that depressed participants may exhibit generalised Emotion Context Insensitivity (ECI), characterised by hyopoattention to both positive and negative information, at short stimulus presentations. The implications of this are discussed.

Diferencias en función de la edad y la autopercepción del envejecimiento en ansiedad, tristeza, soledad y sintomatología comórbida ansioso-depresiva durante el confinamiento por la COVID-19

ObjectivesTo analyze differences by age group in anxiety, depression, loneliness and comorbid anxiety and depression in young people, middle aged adults and older adults during the lock-down period at home due to the COVID-19 pandemic, and to explore the association between negative self-perceptions of aging and psychological symptoms controlling by age group. MethodParticipants are 1501 people (age range 18 to 88 years). Anxiety, sadness, loneliness and self-perceptions of aging were assessed. The sample was divided according to the age group and quartiles (lower, intermediate levels, and higher) of anxiety, sadness, loneliness and self-perceptions of aging. ResultsOlder adults reported lower levels of anxiety and sadness than middle aged adults, and middle aged adults reported lower levels than younger participants. Middle aged adults reported the lowest loneliness, followed by older adults and younger participants. For each age group, those with more negative self-perceptions of aging reported higher anxiety, sadness and loneliness. More comorbid anxiety and sadness was found in younger adults and less in older adults; more depressed participants in the middle aged group, and more older adults and less younger participants were found in the group with the lowest levels of anxiety and sadness. For all the age groups, participants with high levels of comorbid anxiety and sadness are those who report the highest scores in negative self-perceptions of aging. ConclusionsOlder adults reported lower psychological anxiety, sadness and loneliness than the other age groups. Having negative self-perceptions of aging damage psychological health irrespective of the chronological age.

Assessment of family function impact on depression severity among infertile women attending a teaching hospital in South-South Nigeria.

Aim:Family function and husband support can impact depression severity in women with infertility disorder. The aim of this study was to assess the impact of family function and husband support on depression severity among women with infertility disorder at the fertility clinics of a University Teaching Hospital, South-South, Nigeria.Methodology:A cross-sectional descriptive study was carried out among 341 female respondents attending the University of Benin Teaching Hospital fertility clinics over a 3-month period, using a semistructured interviewer administered questionnaire. Data obtained were analyzed.Result:Respondents mean age was 36 ± 5.3 years. The overall prevalence for depression in this study was 42.5% with a breakdown of 64.2%, 30.4% and 5.4% of these depressed participants having mild, moderate and severe depression, respectively. Family dysfunction had a statistically significant relationship with severity of depression in women with infertility (p < 0.001). A statistically significant relationship was established between poor husband support and the severity of depression (p < 0.001).Conclusion:Depression is highly prevalent among women with infertility disorder, severe depression was associated with family dysfunction. Good family function would reduce the severity of depression.

Expectation-induced placebo effect on acute sadness in women with major depression: An experimental investigation

BackgroundMeta-analyses demonstrate that placebo effects play an important role in antidepressant treatment. Expectations seem to constitute a highly relevant placebo mechanism in this context. This study investigated whether an expectation manipulation combined with the intake of an active placebo could reduce acute sadness in depressed participants following a sadness-inducing mood manipulation. MethodsWomen who suffered from a major depressive episode (N = 94) were randomly allocated to the drug expectation group (expectation to receive a fast-operating antidepressant), the placebo expectation group (expectation to receive a placebo) or the no treatment group (no expectation, no placebo). The drug expectation and the placebo expectation group received a placebo. All participants watched a sadness-inducing film. Sadness was assessed at baseline, after randomization and after placebo intake and mood induction. Data were analyzed by a 3 × 3 analysis of variance. ResultsThere were significant between-group differences in sadness change from the baseline after mood induction. While sadness increased in the no treatment group, it did not change in the placebo expectation group. In the drug expectation group, sadness even decreased. LimitationsOnly a single medication intake was simulated. Effects on acute sadness do not allow inferences about depression symptoms. ConclusionThis experimental study found a placebo effect on sadness in clinically depressed participants. The effects were even larger than expected. Future research must investigate placebo effects on depression symptoms as well as long-term placebo intake.

Sex differences in the associations between blood pressure and anxiety and depression scores in a middle-aged and elderly population: The Irish Longitudinal Study on Ageing (TILDA)

BackgroundAnxiety and depression are considered risk factors for cardiovascular diseases (CVDs), but their relationship to blood pressure (BP) is still uncertain. Lifestyle factors and age-related comorbidities may confound these relationships. Our study aimed to evaluate the associations between BP and anxiety and depression scores in a population aged ≥49 years. MethodsData on 8504 participants from The Irish Longitudinal Study on Ageing (TILDA) were analyzed for associations between BP and anxiety and depression questionnaire scores, accounting for relevant confounding factors. ResultsMultivariable analyses showed negative associations between systolic BP and anxiety and depression scores, independent of age, body mass index (BMI), marital status, education level, smoking status, alcohol consumption, level of physical activity, self-reported CVDs (≥2) and antihypertensive medication use in men (coefficient=−0.112, P=0.013; coefficient=−0.051, P=0.026) but not in women (coefficient=-0.001, P=0.855; coefficient=-0.005, P=0.556). Diastolic BP was not associated with anxiety or depression scores in either men (coefficient=−0.018, P=0.223; coefficient=−0.001, P=0.924) or women (coefficient=−0.007, P=0.338; coefficient=−0.015, P=0.293) after adjusting for these same confounding factors. After a follow-up of 4 years, lower BP in subjects not using antihypertensive medications was significantly associated with more anxiety and depression events. LimitationTime-varying confounding factors may have interfered with our results. ConclusionOur results show that systolic BP in a middle-aged and elderly population is negatively associated with anxiety and depression scores in men but not women after adjustment for a range of lifestyle factors. These results contrast with the predisposition of anxious or depressed participants to CVDs in later life when decades of unhealthy lifestyles have persisted.

Cross-cultural exploration of the characteristics, content and themes of intrusive autobiographical memories recalled during depression

ABSTRACTThe recall of intrusive memories is highly prevalent during depression. While past research has examined memory themes and characteristics (e.g., frequency), possible cultural differences in these variables have not been investigated. Furthermore, cross-cultural research has documented content differences in voluntary autobiographical remembering, but such content analyses have not been conducted in regard to intrusive memories. This study, therefore, investigated the characteristics, content and themes of intrusive memories using a 2 (group: European Australian, East Asian) × 2 (depression: depressed, control) cross-sectional design. European Australian (n = 46) and East Asian (n = 45) participants living in Australia reported two memories in real-time using an online memory diary and rated the characteristics of their memories. East Asian participants reported more frequent and distressing memories, compared to European Australians, while the European Australian group reported more specific memories than the East Asian group. Most of the characteristics, themes and content variables, however, did not differ between cultural groups. Additionally, depressed participants, regardless of cultural group, reported more frequent, distressing and numbing memories, compared to healthy controls. These findings suggest that while depressive symptomatology impacts the experience of intrusive memories, memory content and characteristics are largely similar across the two cultural groups.

A bayesian approach to examining default mode network functional connectivity and cognitive performance in major depressive disorder

To reconcile the inconsistency of the association between the resting-state functional connectivity (RSFC) and cognitive performance in healthy and depressed groups due to high variance of both measures, we proposed a Bayesian spatio-temporal model to precisely and accurately estimate the RSFC in depressed and nondepressed participants. This model was employed to estimate spatially-adjusted functional connectivity (saFC) in the extended default mode network (DMN) that was hypothesized to correlate with cognitive performance in both depressed and nondepressed. Multiple linear regression models were used to study the relationship between DMN saFC and cognitive performance scores measured in the following four cognitive domains while adjusting for age, sex, and education. In ROI pairs including the posterior cingulate (PCC) and anterior cingulate (ACC) cortex regions, the relationship between connectivity and cognition was found only with the Bayesian approach. Moreover, only the Bayesian approach was able to detect a significant diagnostic difference in the association in ROI pairs, including both PCC and ACC regions, due to smaller variance for the saFC estimator. The results confirm that a reliable and precise saFC estimator, based on the Bayesian model, can foster scientific discovery that may not be feasible with the conventional ROI-based FC estimator (denoted as ‘AVG-FC’).

Emotional complexity across the life story: Elevated negative emodiversity and diminished positive emodiversity in sufferers of recurrent depression

BackgroundGreater diversity in the experience of negative and positive emotions – emodiversity - is associated with better mental health outcomes in the general population (Quoidbach et al. 2014). However, conceptual accounts of depression suggest this might differ in clinical depression. In this study, the diversity of negative and positive emotion experiences as remembered by a recurrently depressed sample and a never-depressed control group were compared. MethodsEmodiversity was assessed using a life structure card sort task which allowed for the assessment of memory for emotional experience over the life course. Depressed (n=34) and non-depressed (n=34) participants completed the card sort task, from which emodiversity metrics were calculated for negative and positive emotion experience. ResultsDepressed individuals showed recollections of enhanced emodiversity across negative emotion but reduced emodiversity across positive emotion, relative to never-depressed individuals. LimitationsThis study involved a relatively small sample size. DiscussionThis study indicates that greater diversity of negative emotion experience, which has been interpreted as a protective factor against depressed mood in community samples (Quoidbach et al., 2014), instead characterises the remembered experience of recurrent clinical depression. The finding that positive emodiversity is adaptive in depression suggests that therapeutic outcomes may be improved by facilitating exposure to a diverse range of positive emotions. These findings indicate that the relationship between emotion diversity and mental health is more complex than hitherto assumed.

Reductions in anti-inflammatory gut bacteria are associated with depression in a sample of young adults

We assessed the gut microbiota of 90 American young adults, comparing 43 participants with major depressive disorder (MDD) and 47 healthy controls, and found that the MDD subjects had significantly different gut microbiota compared to the healthy controls at multiple taxonomic levels. At the phylum level, participants with MDD had lower levels of Firmicutes and higher levels of Bacteroidetes, with similar trends in the at the class (Clostridia and Bacteroidia) and order (Clostridiales and Bacteroidales) levels. At the genus level, the MDD group had lower levels of Faecalibacterium and other related members of the family Ruminococcaceae, which was also reduced relative to healthy controls. Additionally, the class Gammaproteobacteria and genus Flavonifractor were enriched in participants with MDD. Accordingly, predicted functional differences between the two groups include a reduced abundance of short-chain fatty acid production pathways in the MDD group. We also demonstrated that the magnitude of taxonomic changes was associated with the severity of depressive symptoms in many cases, and that most changes were present regardless of whether depressed participants were taking psychotropic medications. Overall, our results support a link between MDD and lower levels of anti-inflammatory, butyrate-producing bacteria, and may support a connection between the gut microbiota and the chronic, low-grade inflammation often observed in MDD patients.

Childhood Cat Bites Relate to Increased Adulthood Severity of Schizotypy, Psychotic-Like Experiences, and Social Anhedonia in a Transdiagnostic Psychiatric Sample

Introduction: Previous research has linked childhood cat scratches and bites to an increased risk for depression, and childhood cat ownership to increased risk of schizophrenia, bipolar disorder, and social anhedonia. Our group previously reported that childhood cat bites, but not ownership, related to increased schizotypy severity in an undergraduate sample. Methods: The current study expands this research by inquiring about cat bites and ownership in a transdiagnostic adult sample (N = 162; 51% female; mean age = 38.15, SD = 10.65), composed of schizophrenia spectrum disorders (n = 30), bipolar disorders (n = 30), unipolar depression (n = 23), and nonpsychiatric participants (n = 79). Participants completed a diagnostic interview, scales of symptom severity, and a cat interaction history interview. Results: Across the entire sample, self-report of cat bites prior to age 13, but not after, related to greater current severity of overall schizotypy, self-reported and clinician-rated psychotic-like symptoms, and social anhedonia, when compared to individuals who reported no lifetime cat bites. Cat bites prior to age 13 did not relate to severity of depression, non-social anhedonia, or clinician-rated negative symptoms. Self-report of residing with a cat prior to age 13, or a first cat bite after age 12, did not relate to any symptom severity measure examined. Conclusions: One theory for these findings is that an unknown infectious agent common in cat saliva interacted with brain development in childhood to increase the likelihood of these symptoms. A novel theory for the infectious agent Pasteurella multocidais discussed. Future research can examine candidate infectious agents to identify potential causal mechanisms for these relationships.

Event-Related Potentials to Changes in Sound Intensity Demonstrate Alterations in Brain Function Related to Depression and Aging.

Measures of the brain’s automatic electrophysiological responses to sounds represent a potential tool for identifying age- and depression-related neural markers. However, these markers have rarely been studied related to aging and depression within one study. Here, we investigated auditory event-related potentials (ERPs) in the brain that may show different alterations related to aging and depression. We used an oddball condition employing changes in sound intensity to investigate: (i) sound intensity dependence; (ii) sensory gating; and (iii) change detection, all within a single paradigm. The ERPs of younger (18–40 years) and older (62–80 years) depressed female participants and age-matched non-depressed participants were measured. Intensity dependence was examined as the difference between N1 responses to repeated high- and low-intensity sounds, sensory gating as N1 responses to rare and repeated sounds, and change detection as indexed by the mismatch negativity (MMN). We found that intensity dependence was greater in older participants than younger ones, indicating effects related to aging but not to depression. For sensory gating, we found depression- and age-related alterations as increased N1 responses. No group differences were found for MMN. Although a sensory gating deficit was expected in older adults, this study is the first to demonstrate age-related overexcitability in sound intensity dependency. The results indicate that automatic brain responses to sound intensity changes are suitable for studying age- and depression-related neural markers but may not be sensitive enough to differentiate the effects of aging and depression.

Daily Interpersonal and Noninterpersonal Stress Reactivity in Current and Remitted Depression

Major stressful life events are known to predict depression onset, but relatively few studies have examined the interplay of daily stress and negative affect, particularly in clinical samples. Preliminary research has been inconclusive whether only current depression is characterized by amplified emotional reactivity to stress, or whether these patterns are equally strong in those with any history of depression. Twenty-three participants with current major depression, 38 with remitted depression, and 43 with no history of depression completed 2 weeks of ecological momentary assessment to examine reactivity to perceived stress, negative daily events, and interpersonal versus noninterpersonal daily events. Currently depressed individuals demonstrated greater reactivity (i.e. greater increases in negative affect) in response to daily perceived stress, relative to previously depressed and never depressed individuals. Furthermore, while previously and never depressed individuals exhibited equal reactivity to interpersonal and noninterpersonal stress, currently depressed participants were particularly sensitive to interpersonal negative events. These microlongitudinal results extend prior longitudinal evidence of the critical role of interpersonal stress in the course of major depression. The findings emphasize the importance of cognitive interventions that target negative interpretations of daily events.

THE IMPACT OF SSRI TREATMENT OF MAJOR DEPRESSION ON GAIT AND POSTURAL STABILITY IN OLDER ADULTS: A PILOT FEASIBILITY STUDY

Introduction Falls are a common and potentially catastrophic event in older adults, and mortality due to falls is increasing. Older adults with psychiatric and cognitive disorders are at particularly high risk of falls and are at high risk for the negative consequences of falls, including fear of falling, functional decline, injury and dependence. Geriatric psychiatrists are confronted with a tension between the treatment of distressing psychiatric symptoms and disorders in older adults, and the concern about increasing the risk for falls. In particular, antidepressants are among the most commonly prescribed drugs in older adults, and the relationship between these drugs and falls events has been established through epidemiological studies. However, these studies are confounded by indication, in that depression itself is a known risk factor for falls. To date, little is known about the specific mechanisms of SSRI-related falls. The objective of this study was to determine the feasibility of a longitudinal study of the impact of sertraline treatment on gait and postural stability, and to establish the effect sizes for a fully powered study. Methods We completed a 12-week open label pilot observational study of sertraline for major depression in older adults. This study used instrumented walkway to measure features of gait stability and FallsLab (a 2-D motion platform) to measure postural stability and balance recovery reactions. Gait and dynamic stability of older adults with depression (n=12) at baseline and 3,6, and 12 weeks after initiation of sertraline was compared to the performance of a group of healthy controls (n=8). Results There were consistent baseline differences between depressed and control participants in their gait and postural stability, which persisted despite improvement in depressive symptoms. Short-term changes in gait stability were observed at 3 weeks after starting sertraline, which resolved by 6 weeks. Depressed individuals on sertraline became less cautious in their gait over time, as measured by decreased double stance time, and had worse standing postural sway. There were no changes over time with treatment in standing or dynamic postural stability. Healthy control and depressed participants showed some degree of practice effect in assessments over time. From the perspective of feasibility, depressed older adults with fear of falling did not tolerate the perturbations, with a high withdrawal rate in that group. Conclusions There are subtle changes in gait and stability observable after treatment with antidepressants, but important methodological issues need to be addressed, including practice effects with repeated assessments and development of an adequately challenging balance recovery paradigm which is acceptable to depressed older adults. This research was funded by: Dean's Fund, University of Toronto; UHN psychiatric consultants research grant; Walter and Maria Schroeder Institute for Brain Innovation and Recovery.

Association of Depression and Eating Disorders Among University Students in Lahore

ABSTRACT: Adolescence and young adulthood are the most susceptible age groupsfor developing eating disorders and depression, for both males and females. In thisresearch, we aimed to study the association of depression and eating disorders instudents from different universities of Lahore. It was a quantitative and cross-sectionaldesign and the sample constituted of 327 university students of 17 to 25 years of age.Participants were selected through convenience sampling. Instruments 'EatingAttitudes Test-26' (EAT-26) and 'Center of Epidemiologic Studies Short DepressionScale-10' (CESD-10) were applied to assess presence of depression and eatingdisorders. A score of 20 and above on EAT-26 was considered a cut-off to determinesusceptibility to eating disorders, whereas 10 or more on CESD-10 was the indicatorsfor higher risk for depression. Descriptive statistics (mean, standard deviation,frequency and percentage) were calculated for all continuous and categorical variables.Chi square and odds ratio were applied to assess association between depression andeating disorders. The study participants had higher prevalence of depression than eating disorders (58.3% and 37% respectively). The risk of eating disorders was higher in depressed individuals, especially in young females (21 years old and younger), who also had higher susceptibility towards both depression and eating disorders. Individualsbelonging to middle-income families and those who paid rent were more depressed. Significant association was seen between being a day-scholar and higher risks of eating disorders. Although, results revealed that association between eating disorders and depression were not significant (p=0.226), but depressed participants had higher chances of having eating disorders.

Everyday emotional dynamics in major depression.

The present study aimed to investigate the everyday emotional dynamics of depressed individuals, especially the role of emotional inertia, emotional context insensitivity, and emotional variability and instability. Using ecological momentary assessment, 40 currently depressed individuals and 40 healthy controls reported on their current emotional state and current activities 10 times a day for 4 consecutive days. There were no differences in the dynamics of positive affect (PA) between depressed and healthy subjects. Depressed participants' negative affect (NA), however, was found to be more inert than in healthy controls, while at the same time being more variable and more reactive to positive events. There was also an association between emotional instability and depression, but this was rendered nonsignificant when analyses were controlled for emotional variability. Altogether, emotional dynamics of NA appear to be more prominently disturbed in depression compared to PA. Results support earlier findings on NA emotional variability as well as inertia in depressed patients. In addition, there was some evidence for a mood brightening effect in depression. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

An Acoustic Study of Fundamental Frequency and Pauses in Depressive Teenagers in Thailand: A Pilot Study

Depression is a major public health problem among Thais. It has been reported that 30% of 70 million people living in Thailand suffer from depression. Suicide is a potential end result from mental illness, which normally involves depression. Diagnosis and treatment are key factors in the prevention of depression. In traditional diagnosis, there are two key methods of testing: (i) a screening test and interview and (ii) a biomarker test. In recent years, detecting depression with speech—a kind of biomarker test— has gained high acceptance. Cues of suprasegments in speech, such as pauses, loudness, tones, rhythm, and phonation, have been scientifically proven using acoustic methods of being indicators of depression. This paper has two main objectives: (i) to conduct a review of the use of suprasegments as cues and an analysis of the cues capable of indicating depression in Thailand and (ii) to analyze an acoustic study of pitch measured by the fundamental frequency and silent pause length in depressed and non-depressed participants. The method used in the study is the acoustic method of linguistics. Praat program version 6.2.09 was used to analyze the data. This is a pilot study of three depressed Thai students aged 20 compared with three non-depressed Thai participants. We propose a new perspective upon Thai language speech indicators that combines two or more cues in detecting depression (e.g. depression inventory with pause duration and word signs). Interestingly, it was found that the pitch of Thai tones may not be an appropriate cue for depression in Thais. This result conflicts with previous research conducted in other non-tonal languages. The results of this study lay the foundation for a Thai speech index for depression that can be further developed for the detection of depression.

Bidirectional longitudinal associations of omega-3 polyunsaturated fatty acid plasma levels with depressive disorders

BackgroundTemporality of the association of low omega-3 polyunsaturated fatty acid (n-3 PUFA) plasma levels with depression remains questionable. To determine the underlying nature of these associations, this study examined the bidirectional longitudinal associations of n-3 PUFA plasma levels with (presence, onset and course of) depressive disorders and symptoms. MethodsBaseline (n = 2912, 28.6% with current depressive disorder) and 6-year follow-up data (n = 1966, 13.0% with current depressive disorder) of the Netherlands Study of Depression and Anxiety (NESDA) were used. Depression diagnoses and symptoms were based on psychiatric interviews and self-report questionnaires. N-3 PUFA levels (ratio of total fatty acids (mmol%)), were assessed using nuclear magnetic resonance. ResultsUsing two waves of data, n-3 PUFA levels were lower among depressed persons, as compared to healthy controls (Beta = −0.047, SE = 0.011, p < .001). Nevertheless, baseline n-3 PUFA levels were not consistently associated with subsequent change in depressive symptoms, onset or remission of depressive disorders over 6 years. Furthermore, the difference in n-3 PUFA levels detected at baseline between depressed and non-depressed participants tended to dissipate over 6 years (depression-by-time estimate: p = .011). Finally, subjects depressed both at baseline and at 6-year follow up had consistently lower n-3 PUFA levels over the entire follow-up as compared to those who had never been depressed. Change in depressive disorders across waves was not consistently accompanied by change in n-3 PUFA levels over time. LimitationsNo data on intermediate time points and EPA levels were available. ConclusionsDespite significant cross-sectional associations between n-3 PUFA plasma levels and depressive disorders and severity, this 6-year longitudinal study could not confirm an uni- or bidirectional association over time. The association between depression and n-3 PUFA plasma levels is unlikely to be causal.