Effect of 4 weeks daily wild blueberry supplementation on symptoms of depression in adolescents.

Adolescence is an important period for cognitive maturation and emotional regulation, and this age group is particularly vulnerable to developing depression. Diets rich in fruits and vegetables have been associated with decreased risk of developing depressive disorders across the lifespan, maybe due to the high flavonoid content of these foods. Previously, we have shown increases in transient positive affect (PA) in both children and young adults 2 h after administration of a wild blueberry (WBB) intervention. Here, using a randomised double-blind, placebo-controlled trial, we investigated the effects of 4 weeks, daily WBB supplementation (containing about 253 mg anthocyanins) on transient and chronic mood in adolescents. Healthy 12-17-year old (n 64, thirty-five females) participants were randomly assigned to receive either a WBB or matched placebo supplementation. Depression and anxiety symptoms were assessed before and after the intervention period using the Mood and Feeling Questionnaire and Revised Child Anxiety and Depression Scale. Transient affect was assessed before, 2 weeks and at 4 weeks using PA and negative affect. Following the intervention period, there were significantly fewer self-reported depression symptoms in participants who were supplemented with WBB compared with placebo (P = 0·02, 95 % CI -6·71, -5·35). There was no between-group effect on anxiety symptoms or on transient affect. Further investigation is required to identify specific mechanisms that link flavonoids consumption and mood. If replicated, the observed effects of WBB supplementation may be a potential prevention strategy for adolescent depression and may have benefits for public mental health.

A test of the CaR-FA-X mechanisms and depression in adolescents.

People who have depression have difficulty recalling specific autobiographical information (Sumner, (2011) The mechanisms underlying overgeneral autobiographical memory: An evaluative review of evidence for the Ca R-FA-X model. Clinical Psychology Review, 3231(1), 34-48). This is called overgeneral autobiographical memory (OGM) and is associated with the development and persistence of depression. Williams, Barnhofer, Crane, Hermans, Raes, Watkins, & Dalgleish (2007 Autobiographical memory specificity and emotional disorder. Psychological Bulletin, 133(1), 122-148) proposed that OGM is maintained by three mechanisms: capture and rumination (CaR), functional avoidance (FA), and impaired executive control (X), and integrated these into the CaR-FA-X model. The aim of this study was to assess OGM and test the CaR-FA-X model in adolescents with low mood. We recruited 29 young people aged 12-17 with elevated symptoms of depression and 29 with minimal symptoms of depression, matched for gender and age. After controlling for IQ, adolescents with elevated depression retrieved fewer specific memories, ruminated more, and had poorer working memory and verbal fluency than adolescents with minimal depression. The groups did not differ on measures of inhibition or functional avoidance. The CaR-FA-X model was therefore partially supported. These results confirm that there is a relationship between low mood and OGM in young people and that OGM may arise as consequence of impaired working memory and verbal fluency and cognitive interference due to rumination.

Effects of Acute Blueberry Flavonoids on Mood in Children and Young Adults.

Epidemiological evidence suggests that consumption of flavonoids (usually via fruits and vegetables) is associated with decreased risk of developing depression. One plausible explanation for this association is the well-documented beneficial effects of flavonoids on executive function (EF). Impaired EF is linked to cognitive processes (e.g., rumination) that maintain depression and low mood; therefore, improved EF may reduce depressionogenic cognitive processes and improve mood. Study 1: 21 young adults (18-21 years old) consumed a flavonoid-rich blueberry drink and a matched placebo in a counterbalanced cross-over design. Study 2: 50 children (7-10 years old) were randomly assigned to a flavonoid-rich blueberry drink or a matched placebo. In both studies, participants and researchers were blind to the experimental condition, and mood was assessed using the Positive and Negative Affect Schedule before and 2 h after consumption of the drinks. In both studies, the blueberry intervention increased positive affect (significant drink by session interaction) but had no effect on negative affect. This observed effect of flavonoids on positive affect in two independent samples is of potential practical value in improving public health. If the effect of flavonoids on positive affect is replicated, further investigation will be needed to identify the mechanisms that link flavonoid interventions with improved positive mood.

Is there an association between diet and depression in children and adolescents? A systematic review.

This review critically evaluates previous studies investigating the association between dietary intake of children and young people and depression and related mental health problems. A systematic literature search was conducted using electronic databases such as PsycINFO, MEDLINE, PubMed and Cochrane. A total of twenty studies were identified that met inclusion criteria and were subsequently rated for quality. The studies used a range of methods to measure dietary intake and mental health. Important potential confounding variables (e.g. socio-economic status) were often not included or controlled. There were also inconsistencies in the use of key constructs, which made comparisons between studies difficult. Despite some contradictory results, overall there was support for an association between healthy dietary patterns or consumption of a high-quality diet and lower levels of depression or better mental health. Similarly, there was a relationship between unhealthy diet and consumption of low-quality diet and depression or poor mental health. However, where significant relationships were reported, effect sizes were small. Future research on the relationship between diet and mental health in young people should use more clearly defined constructs to define diet and include or control for important confounders.

Is cognitive bias modification training truly beneficial for adolescents?

BACKGROUND: Cognitive Bias Modification (CBM) has been shown to change interpretation biases commonly associated with anxiety and depression and may help ameliorate symptoms of these disorders. However, its evidence base for adolescents is scarce. Previous results have been hard to interpret because of methodological issues. In particular, many studies have used negative bias training as the control condition. This would tend to inflate any apparent benefits of CBM compared to a neutral control. Most studies also only examined the effects of a single training session and lacked follow-up assessment or ecologically valid outcome measures. METHOD: Seventy-four adolescents, aged 16-18 years, were randomised to two sessions of CBM training or neutral control. Interpretation bias and mood were assessed three times: at baseline, immediately post-training and 1 week post-training. A controlled experimental stressor was also used, and responses to everyday stressors were recorded for 1 week after training to assess responses to psychological challenges. Feedback for the training programme was collected. RESULTS: The CBM group reported a greater reduction in negative affect than control participants. However, other hypothesised advantages of CBM were not demonstrated. Regardless of training group, participants reported increased positive interpretations, decreased negative interpretations, reduced depressive symptoms and no change in trait anxiety. The two groups did not differ in their stress reactivity. After controlling for group differences in training performance, all the mood effects disappeared. CONCLUSIONS: When tested under stringent experimental conditions the effects of CBM in healthy adolescents appear to be minimal. Future studies should concentrate on participants with elevated cognitive biases and/or mood symptoms who may be more sensitive to CBM.

Randomized controlled trial of parent-enhanced CBT compared with individual CBT for obsessive-compulsive disorder in young people.

OBJECTIVE: Obsessive-compulsive disorder (OCD) in young people can be effectively treated with Cognitive Behavior Therapy (CBT). Practice guidelines in the United Kingdom recommend that CBT be delivered with parental or family involvement; however, there is no evidence from randomized trials that this enhances effectiveness. The aim of this trial was to assess if CBT with high parental involvement was more effective than CBT with low parental involvement (individual CBT) in reducing symptoms of OCD. METHOD: Fifty young people ages 12-17 years with OCD were randomly allocated to individual CBT or parent-enhanced CBT. In parent-enhanced CBT parents attended all treatment sessions; in individual CBT, parents attended only Sessions 1, 7, and the final session. Participants received up to 14 sessions of CBT. Data were analyzed using intent-to-treat and per-protocol methods. The primary outcome measure was the Children's Yale-Brown Obsessive Compulsion Scale (Scahill et al., 1997). RESULTS: Both forms of CBT significantly reduced symptoms of OCD and anxiety. Change in OCD symptoms was maintained at 6 months. Per-protocol analysis suggested that parent-enhanced CBT may be associated with significantly larger reductions in anxiety symptoms. CONCLUSIONS: High and low parental involvement in CBT for OCD in young people were both effective, and there was no evidence that 1 method of delivery was superior on the primary outcome measure. However, this study was small. Future trials should be adequately powered and examine interactions with the age of the young person and comorbid anxiety disorders.

CD33/Siglec-3 binding specificity, expression pattern, and consequences of gene deletion in mice.

Mouse CD33/Siglec-3 (mCD33) is the apparent ortholog of human CD33/Siglec-3 (hCD33), a member of the Siglec (sialic acid-binding Ig superfamily lectin) family of sialic acid-recognizing cell-surface lectins. We examined the binding specificity and expression pattern of mCD33 and explored its functions by generating mice deficient in this molecule. Like hCD33, mCD33 is expressed on myeloid precursors in the bone marrow, albeit mostly in the more mature stages of the granulocytic lineage. Moreover, unlike hCD33, mCD33 in peripheral blood is primarily expressed on granulocytes. Also, unlike hCD33, mCD33 did not bind to alpha2-3- or alpha2-6-linked sialic acids on lactosamine units. Instead, it showed distinctive sialic acid-dependent binding only to the short O-linked glycans of certain mucins and weak binding to the sialyl-Tn epitope. Binding was enhanced by removal of 9-O-acetyl groups and attenuated by truncation of the glycerol-like side chain of sialic acids. Mice deficient in CD33 were viable and fertile in a controlled-access specific-pathogen-free vivarium, showed no major morphological or histological abnormalities, had no changes in bone marrow or peripheral leukocyte subpopulations, and had very minor differences in biochemical and erythrocyte parameters. Cellular responses to intraperitoneally injected proinflammatory stimulants, as well as subsequent interleukin-6 secretion, were also apparently unaffected. These results indicate substantial species differences in CD33 expression patterns and ligand recognition and suggest functional degeneracy between mCD33 and the other CD33-related Siglec proteins expressed on cells of the myeloid lineage.

Generation of mice deficient for macrophage galactose- and N-acetylgalactosamine-specific lectin: limited role in lymphoid and erythroid homeostasis and evidence for multiple lectins.

Macrophage receptors function in pattern recognition for the induction of innate immunity, in cellular communication to mediate the regulation of adaptive immune responses, and in the clearance of some glycosylated cells or glycoproteins from the circulation. They also function in homeostasis by initiating the engulfment of apoptotic cells. Evidence has suggested that macrophage receptors function to recognize cells that are destined for programmed cell death but not yet overtly apoptotic. We have examined the function of a macrophage receptor specific for unsialylated glycoproteins, known as the mouse macrophage galactose- and N-acetylgalactosamine-specific lectin (mMGL) (Ii et al., J. Biol. Chem. 265:11295-11298, 1990; Sato et al., J. Biochem. [Tokyo] 111:331-336, 1992; Yamamoto et al., Biochemistry 33:8159-8166, 1994). With targeted disruption, we tested whether mMGL is necessary for macrophage function, controlled thymic development, the loss of activated CD8 T cells, and the turnover of red blood cells. Evidence indicates that mMGL may play a nonessential role in several of these macrophage functions. Experiments are presented that indicate the existence of another galactose- and N-acetylgalactosamine-recognizing lectin distinct from mMGL. This may explain the absence of a strong phenotype in mMGL-deficient mice.