Linking the serotonin transporter gene, family environments, hippocampal volume and depression onset: a prospective imaging gene × environment analysis

A single imaging gene-environment (IGxE) framework that is able to simultaneously model genetic, neurobiological, and environmental influences on psychopathology outcomes is needed to improve understanding of how complex interrelationships between allelic variation, differences in neuroanatomy or neuroactivity, and environmental experience affect risk for psychiatric disorder. In a longitudinal study of adolescent development we demonstrate the utility of such an IGxE framework by testing whether variation in parental behavior at age 12 altered the strength of an imaging genetics pathway, involving an indirect association between allelic variation in the serotonin transporter gene to variation in hippocampal volume and consequent onset of major depressive disorder by age 18. Results were consistent with the presence of an indirect effect of the serotonin transporter S-allele on depression onset via smaller left and right hippocampal volumes that was significant only in family environments involving either higher levels of parental aggression or lower levels of positive parenting. The previously reported finding of S-allele carriers' increased risk of depression in adverse environments may, therefore, be partly because of the effects of these environments on a neurobiological pathway from the serotonin transporter gene to depression onset that proceeds through variation in hippocampal volume. 

Peripheral proinflammatory markers associated with ketamine response in a preclinical model of antidepressant-resistance

© 2015 Elsevier B.V. Ketamine, N-methyl- d-aspartate (NMDA) receptor antagonist and anti-inflammatory agent, has rapid therapeutic effects in a subset of patients with more intractable forms of depression. Irregular proinflammatory cytokine and acute-reactive protein levels have been reported in clinical and preclinical depression research. We explored the association between the rapid antidepressant-like effects of ketamine and peripheral proinflammatory profile in a model of antidepressant-resistance. Male Wistar rats were pre-treated with ACTH-(1-24) 100. μg/d or saline (0.9%) for 14. d. Antidepressant-like effects were assessed with the forced swim test (FST). Ketamine (10. mg/kg) significantly reduced immobility duration in saline-pretreated control animals. In contrast, a divergent response was observed in ACTH-pretreated antidepressant resistant animals, with 50% responders and 50% non-responders. Plasma samples were analyzed via enzyme-linked immunosorbent assay (ELISA) for interleukin 6 (IL-6), tumour necrosis factor alpha (TNFα) and C-reactive protein (CRP). Levels of CRP and TNFα differentiated ketamine responders and non-responders.

The association between the activity profile and cardiovascular risk.

OBJECTIVES: This study sought to better understand the interrelationships between physical activity and sedentary behaviour and the relationship to risk of cardiovascular disease (CVDR) in adults aged 30-75 years. DESIGN: Cross-sectional. METHODS: Data from two-year waves (2003-2004 and 2005-2006) of the National Health and Nutritional Examination survey were analysed in 2014. Accelerometer-derived time and proportion of time spent sedentary and on moderate-to-vigorous physical activity (MVPA) were calculated to generate four activity profiles based on cut-points to define low and high levels for the respective behaviours. Using health outcome data, CVDR was calculated for each person. Weighted multiple linear regression models were used to evaluate the predicted effects of sedentary and physical activity behaviours on the CVDR score, adjusting for participants' sex, age group, race, annual household income, and accelerometer wear time. RESULTS: The lowest CVDR was observed among Busy Exercisers (high MVPA and low sedentary; 8.5%), whereas Couch Potatoes (low MVPA and high sedentary) had the highest (18.6%). Compared with the reference group (Busy Exercisers), the activity profile associated with the highest CVDR was Couch Potatoes (adjusted mean difference 3.6, SE 0.38, p<0.0001). A smoothed three-dimensional response surface "risk landscape" was developed to better visualise the conjoint associations of MVPA and sedentary behaviour on CVDR for each activity profile. The association between MVPA was greater than that of sedentary behaviour; however, for people with low MVPA, shifts in sedentary behaviour may have the greatest impact on CVDR. CONCLUSIONS: Activity profiles that consider the interrelationships between physical activity and sedentary behaviour differ in terms of CVDR. Future interventions may need to be tailored to specific profiles and be dynamic enough to reflect change in the profile over time.

Family-based interventions for reducing sedentary time in youth: a systematic review of randomized controlled trials

Family involvement in interventions to reduce sedentary time may help foster appropriate long-term screen-based habits in children. This review systematically synthesized evidence from randomized controlled trials of interventions with a family component that targeted reduction of sedentary time, including TV viewing, video games and computer use, in children. MEDLINE, PubMed, PsycInfo, CINAHL and Embase were searched from inception through March 2012. Seventeen articles were considered eligible and included in the review. Studies were judged to be at low-to-moderate risk of bias. Despite inconsistent study results, level of parental involvement, rather than the setting itself, appeared an important determinant of intervention success. Studies including a parental component of medium-to-high intensity were consistently associated with statistically significant changes in sedentary behaviours. Participant age was also identified as a determinant of intervention outcomes; all three studies conducted in pre-school children demonstrated significant decreases in sedentary time. Finally, TV exposure appeared to be related to changes in energy intake rather than physical activity. Future studies should assess the effects of greater parental involvement and child age on success of sedentary behaviour interventions. More research is required to better understand the relationship between screen time and health behaviours, particularly energy intake.

Screen-time weight-loss intervention targeting children at home (SWITCH): a randomized controlled trial

BACKGROUND: Screen-based activities, such as watching television (TV), playing video games, and using computers, are common sedentary behaviors among young people and have been linked with increased energy intake and overweight. Previous home-based sedentary behaviour interventions have been limited by focusing primarily on the child, small sample sizes, and short follow-up periods. The SWITCH (Screen-Time Weight-loss Intervention Targeting Children at Home) study aimed to determine the effect of a home-based, family-delivered intervention to reduce screen-based sedentary behaviour on body composition, sedentary behaviour, physical activity, and diet over 24 weeks in overweight and obese children.

METHODS: A two-arm, parallel, randomized controlled trial was conducted. Children and their primary caregiver living in Auckland, New Zealand were recruited via schools, community centres, and word of mouth. The intervention, delivered over 20 weeks, consisted of a face-to-face meeting with the parent/caregiver and the child to deliver intervention content, which focused on training and educating them to use a wide range of strategies designed to reduce their child's screen time. Families were given Time Machine TV monitoring devices to assist with allocating screen time, activity packages to promote alternative activities, online support via a website, and monthly newsletters. Control participants were given the intervention material on completion of follow-up. The primary outcome was change in children's BMI z-score from baseline to 24 weeks.

RESULTS: Children (n = 251) aged 9-12 years and their primary caregiver were randomized to receive the SWITCH intervention (n = 127) or no intervention (controls; n = 124). There was no significant difference in change of zBMI between the intervention and control groups, although a favorable trend was observed (-0.016; 95% CI: -0.084, 0.051; p = 0.64). There were also no significant differences on secondary outcomes, except for a trend towards increased children's moderate intensity physical activity in the intervention group (24.3 min/d; 95% CI: -0.94, 49.51; p = 0.06).

CONCLUSIONS: A home-based, family-delivered intervention to reduce all leisure-time screen use had no significant effect on screen-time or on BMI at 24 weeks in overweight and obese children aged 9-12 years.

The effect of active video games by ethnicity, sex and fitness: subgroup analysis from a randomised controlled trial

BACKGROUND: The prevention and treatment of childhood obesity is a key public health challenge. However, certain groups within populations have markedly different risk profiles for obesity and related health behaviours. Well-designed subgroup analysis can identify potential differential effects of obesity interventions, which may be important for reducing health inequalities. The study aim was to evaluate the consistency of the effects of active video games across important subgroups in a randomised controlled trial (RCT).

FINDINGS: A two-arm, parallel RCT was conducted in overweight or obese children (n=322; aged 10-14 years) to determine the effect of active video games on body composition. Statistically significant overall treatment effects favouring the intervention group were found for body mass index, body mass index z-score and percentage body fat at 24 weeks. For these outcomes, pre-specified subgroup analyses were conducted among important baseline demographic (ethnicity, sex) and prognostic (cardiovascular fitness) groups. No statistically significant interaction effects were found between the treatment and subgroup terms in the main regression model (p=0.36 to 0.93), indicating a consistent treatment effect across these groups.

CONCLUSIONS: Preliminary evidence suggests an active video games intervention had a consistent positive effect on body composition among important subgroups. This may support the use of these games as a pragmatic public health intervention to displace sedentary behaviour with physical activity in young people.

Validating the multimedia activity recall for children and adolescents in a large New Zealand sample

The aim of the study was to validate the self-report Multimedia Activity Recall for Children and Adolescents (MARCA) against accelerometry for the assessment of physical activity in New Zealand children. Participants (n = 716, 10-18 years) recalled 3-4 days of activity using the MARCA and underwent a partially overlapping 7-day accelerometry protocol during a national survey. Spearman correlation coefficients (ρ) assessed the association between accelerometer-derived counts per minute and MARCA-derived physical activity level and time in locomotion. Both data sources estimated time spent in light and moderate-vigorous physical activity. Association and agreement between methods for light physical activity and moderate-vigorous physical activity was assessed using correlations and Bland-Altman plots respectively, and paired t-tests conducted. Accelerometer-derived activity counts were moderately correlated with both MARCA-derived physical activity level and locomotion (ρ = 0.38, P < 0.0001). The correlation between methods was -0.14 for light physical activity and 0.28 for moderate-vigorous physical activity (P < 0.0001). The MARCA overestimated moderate-vigorous physical activity compared with accelerometry (120 min, P < 0.0001), which increased as moderate-vigorous physical activity time increased. Some sex and ethnicity (Māori [indigenous] versus non-Māori) differences were observed. Overall, the MARCA indicated moderate validity for assessment of physical activity level, locomotion and moderate-vigorous physical activity and poor validity for assessment of light physical activity. This was comparable to other self-report tools. The MARCA has utility for future large-scale research.

Doubly labeled water validation of a computerized use-of-time recall in active young people

OBJECTIVE: Low levels of daily energy expenditure (insufficient physical activity and increased sedentary time) have been associated with adverse health outcomes in young people. The Multimedia Activity Recall for Children and Adolescents (MARCA) is a computerized, self-report, use-of-time tool that can assess daily energy expenditure. The study aim was to validate the MARCA for the estimation of energy expenditure in young people, using the criterion standard doubly labeled water. MATERIALS/METHODS: Over a 15 day assessment period, 32 participants (10-18 years) completed the MARCA and underwent a doubly labeled water protocol. Indirect calorimetry was used to assess resting metabolic rate. Total daily energy expenditure (TEE) and activity-related energy expenditure (AEE) were estimated from both the MARCA and doubly labeled water. Association and agreement between methods for TEE and AEE were assessed using Spearman correlations and Bland-Altman plots, respectively. RESULTS: Compared to doubly labeled water, the MARCA over-estimated TEE by an average of 50 kcal/day (limits of agreement -1 589 to 1 490 kcal/day) and under-estimated AEE 105 kcal/day (limits of agreement -1 404 to 1 614 kcal/day). The MARCA showed strong correlation with doubly labeled water for TEE (rho=0.70, p<0.0001) and moderate correlation for AEE (rho=0.56, p=0.0009). CONCLUSIONS: Overall, the MARCA indicated moderate validity for the assessment of daily TEE and AEE. The wide limits of agreement indicate the MARCA has greater utility for group-level rather than individual-level estimates.

Presleep activities and time of sleep onset in children

OBJECTIVE: Presleep activities have been implicated in the declining sleep duration of young people. A use-of-time approach may be used to describe the presleep period. The study aims were to describe the activities undertaken 90 minutes before sleep onset and to examine the association between activities and time of sleep onset in New Zealand young people. METHODS: Participants (N = 2017; 5-18 years) self-reported their time use as part of a national survey. All activities reported in the 90 minutes before sleep were extracted. The top 20 activities were grouped into 3 behavioral sets: screen sedentary time, nonscreen sedentary time, and self-care. An adjusted regression model was used to estimate presleep time spent in each behavioral set for 4 distinct categories of sleep onset (very early, early, late, or very late), and the differences between sleep onset categories were tested. RESULTS: In the entire sample, television watching was the most commonly reported activity, and screen sedentary time accounted for ∼30 minutes of the 90-minute presleep period. Participants with a later sleep onset had significantly greater engagement in screen time than those with an earlier sleep onset. Conversely, those with an earlier sleep onset spent significantly greater time in nonscreen sedentary activities and self-care. CONCLUSIONS: Screen sedentary time dominated the presleep period in this sample and was associated with a later sleep onset. The development of interventions to reduce screen-based behaviors in the presleep period may promote earlier sleep onset and ultimately improved sleep duration in young people.

Active video games: the mediating effect of aerobic fitness on body composition

BACKGROUND: Increased understanding of why and how physical activity impacts on health outcomes is needed to increase the effectiveness of physical activity interventions. A recent randomized controlled trial of an active video game (PlayStation EyeToy™) intervention showed a statistically significant treatment effect on the primary outcome, change from baseline in body mass index (BMI), which favored the intervention group at 24 weeks. In this short paper we evaluate the mediating effects of the secondary outcomes.

OBJECTIVE: To identify mediators of the effect of an active video games intervention on body composition.

METHODS: Data from a two-arm parallel randomized controlled trial of an active video game intervention (n = 322) were analyzed. The primary outcome was change from baseline in BMI. A priori secondary outcomes were considered as potential mediators of the intervention on BMI, including aerobic fitness (VO2Max), time spent in moderate-to-vigorous physical activity (MVPA), and food snacking at 24 weeks.

RESULTS: Only aerobic fitness at 24 weeks met the conditions for mediation, and was a significant mediator of BMI.

CONCLUSION: Playing active video games can have a positive effect on body composition in overweight or obese children and this effect is most likely mediated through improved aerobic fitness. Future trials should examine other potential mediators related to this type of intervention.

Guided imagery to improve functional outcomes post-anterior cruciate ligament repair: randomized-controlled pilot trial

Imagery can improve functional outcomes post-anterior cruciate ligament repair (ACLR). Research is needed to investigate potential mechanisms for this effect. The aim of this study was to (a) evaluate the effectiveness of an imagery intervention to improve functional outcomes post-ACLR, and (b) explore potential mechanisms. A randomized-controlled pilot trial was conducted. Participants were randomized to guided imagery and standard rehabilitation or standard rehabilitation alone (control). The primary outcome was knee strength 6-month post-operatively. Secondary outcomes were knee laxity at 6-months, and change in psychological (self-efficacy) and neurohormonal (adrenaline, noradrenaline, dopamine) variables. Participants (n=21; 62% male) were 34.86 (SD 8.84) years. Following the intervention, no statistical differences between groups for knee strength extension at 180°/s (t=-0.43, P=0.67), or at 60°/s (t=-0.72, P=0.48) were found. A statistically significant effect was found for knee laxity, F=4.67, P<0.05, mean difference of -3.02 (95% CI -4.44 to -1.60), favoring the intervention. No differences were found for self-efficacy; however, an overall effect was found for noradrenaline, F(1, 19) 19.65, P<0.001, η(2) =0.52, and dopamine, F(1, 19) 6.23, P=0.02, η(2) =0.29, favoring the intervention. This imagery intervention improved knee laxity and healing-related neurobiological factors.

Self-efficacy, imagery use, and adherence during injury rehabilitation

Previous observational studies examining imagery, self-efficacy, and adherence during injury rehabilitation have been cross-sectional and thus have not provided a clear representation of what occurs over the course of the rehabilitation period. The objectives of this research were (1) to examine the temporal patterns of imagery, self-efficacy, and rehabilitation adherence during an 8-week rehabilitation program and (2) to identify the time-order relationships between imagery, self-efficacy, and adherence. The design of the study was prospective and observational. 90 injured people (n=57 males; n=33 females) aged 18-78 years attending an injury rehabilitation clinic participated. The main outcome measures were imagery (cognitive, motivational, and healing), self-efficacy (task and coping), and rehabilitation adherence (duration, quality, and frequency). Results indicated that task efficacy, imagery use, and adherence levels remained stable, while coping efficacy declined over time. During the course of rehabilitation, moderate to strong reciprocal relationships existed between self-efficacy and adherence to rehabilitation. Weak to moderate relationships were found between imagery use and rehabilitation adherence. The results of this study can be used to inform the development of interventions steeped in self-efficacy and imagery aimed at improving rehabilitation adherence and treatment outcome.

Self-report use-of-time tools for the assessment of physical activity and sedentary behaviour in young people: systematic review

UNLABELLED: Regular physical activity and limiting extended periods of sitting are two behaviours critical for the prevention of obesity in young people. The purpose of the systematic review was to synthesize the psychometric evidence for self-report use-of-time tools that assess these behaviours. Articles were retrieved that reported reliability and/or validity for use-of-time tools in participants aged 18 years or under. Outcome variables were physical activity, sedentary behaviour and energy expenditure. Study quality was appraised, and the results summarized narratively. Sixteen studies and six different tools were identified. The tools were the Previous Day Physical Activity Recall, the Three-Day Physical Activity Recall, the Physical Activity Interview, the Computerized Activity Recall, the Activitygram, and the Multimedia Activity Recall for Children and Adolescents. Overall, tools indicated moderate validity compared with objective and criterion comparison methods. Generally, validity correlation coefficients were in the range of 0.30-0.40. Correlation coefficients for test-retest reliability ranged widely from 0.24 to 0.98. CONCLUSION: Use-of-time tools have indicated moderate reliability and validity for the assessment of physical activity and energy expenditure. Future research should focus on using criterion methods and on validating specifically for sedentary behaviour outcomes. Implementation of these tools for population surveillance should be considered.

Comparison of two modes of delivery of an exercise prescription scheme

AIM: Green Prescription (GRx) referrals from health professionals have been shown to be effective for increasing the physical activity levels of patients. Little is known about which methods of delivering the programme represents the best value for money. The purpose of this paper was to compare the cost and outcomes of two modes of delivery of a GRx programme. One mode offered phone support involving monthly telephone calls over a 3-4 month period to encourage physical activity participation. A second mode offered community support via weekly face-to-face support group meetings in which physical activities were offered. METHODS: The evaluation involved staff interviews, patient interviews and analysis of GRx records for the 2007 calendar year. RESULTS: There was a large rate of drop-out (68%) from GRx referral to registration. For those who registered, there was a clear preference for community support, and engagement of Maori and Pacific peoples was higher in this mode of delivery. The proportion (but not absolute number) of people who successfully completed their mode of delivery was higher with phone support. However, participants in community support self-reported a significantly greater number of days of exercise per week than those in phone support. The total expected cost per person for phone support was $102.07 and $108.15 for community support. A greater proportion of participants in community support were very satisfied overall with their mode of delivery. CONCLUSION: The two modes were comparable in cost and outcomes, though there was greater penetration of target ethnic populations in community support. Providing a choice of GRx mode of delivery allows participants to choose based on their personal and cultural needs.

Effects of active video games on body composition: a randomized controlled trial

BACKGROUND: Sedentary activities such as video gaming are independently associated with obesity. Active video games, in which players physically interact with images on screen, may help increase physical activity and improve body composition.

OBJECTIVE: The aim of this study was to evaluate the effect of active video games over a 6-mo period on weight, body composition, physical activity, and physical fitness.

DESIGN: We conducted a 2-arm, parallel, randomized controlled trial in Auckland, New Zealand. A total of 322 overweight and obese children aged 10-14 y, who were current users of sedentary video games, were randomly assigned at a 1:1 ratio to receive either an active video game upgrade package (intervention, n = 160) or to have no change (control group, n = 162). The primary outcome was the change from baseline in body mass index (BMI; in kg/m(2)). Secondary outcomes were changes in percentage body fat, physical activity, cardiorespiratory fitness, video game play, and food snacking.

RESULTS: At 24 wk, the treatment effect on BMI (-0.24; 95% CI: -0.44, -0.05; P = 0.02) favored the intervention group. The change (±SE) in BMI from baseline increased in the control group (0.34 ± 0.08) but remained the same in the intervention group (0.09 ± 0.08). There was also evidence of a reduction in body fat in the intervention group (-0.83%; 95% CI: -1.54%, -0.12%; P = 0.02). The change in daily time spent playing active video games at 24 wk increased (10.03 min; 95% CI: 6.26, 13.81 min; P < 0.0001) with the intervention accompanied by a reduction in the change in daily time spent playing nonactive video games (-9.39 min; 95% CI: -19.38, 0.59 min; P = 0.06).

CONCLUSION: An active video game intervention has a small but definite effect on BMI and body composition in overweight and obese children.