Susanne S. Hoeppner

Urgent need for a common metric to make precipitation manipulation experiments comparable

In recent decades, researchers have increasingly focused attention on how climatic change will affect ecosystem functioning. Much of this research has centred on the effects of rising atmospheric CO2 concentrations and increasing temperatures (e.g. Ainsworth & Long, 2005; Wu et al., 2011). The consequences of altered precipitation patterns, by contrast, have received far less attention. The results of precipitation manipulation experiments were only recently synthesized for the first time (Wu et al., 2011), and the conclusions that can be drawn regarding global patterns remain preliminary. In general, reduced water inputs slow ecosystem processes, while increased rainfall enhances plant productivity (Wu et al., 2011), but it remains unclear how this response differs among ecosystems. When synthesizing water manipulation experiments, firm conclusions are not only precluded by the insufficient number of data points (Wu et al., 2011), but also by the difficulty of defining the magnitude of the perturbation experienced by the biota (further coined the ‘actual’ treatment). Unlike in the case of, for example, elevated CO2, the magnitude of the imposed treatment (e.g. )20% precipitation vs +300 ppm CO2) does not clearly indicate the actual treatment. Many factors influence the way an ecosystem experiences a change in rainfall; of greatest importance to the ecosystem is not the amount of incoming precipitation, but rather the amount of water that plants have access to. This ‘plant available water’ strongly depends on factors such as soil texture and rooting depth (Tolk, 2003), and the latter can show substantial seasonal and interannual variation (Knapp et al., 2008) and may differ between treatments. Additionally, runoff water and stem flow can complicate estimations of the magnitude of an imposed manipulation (Cotrufo et al., 2011), and plants that access groundwater supplies can complicate interpretations of treatment effects. If we want to understand why plant responses to altered precipitation differ among ecosystems, comparisons of effects of precipitation manipulations must use a more ecologically meaningful metric to describe the actual treatment than merely the change in precipitation. Without such a relevant ‘common denominator’, observed differences in ecosystem responses to altered precipitation may reflect differences not only in ecosystem properties, but also in the actual treatment. Potential metrics for quantification of the actual treatment

Leaf-Level Gas Exchange and Foliar Chemistry of Common Old-Field Species Responding to Warming and Precipitation Treatments.

We investigated the shifts in plant carbon (C) and water dynamics by measuring rates of photosynthesis, transpiration, and instantaneous water use efficiency (WUE) in three common species of “old-field” plants—two C3 forb species (Plantago lanceolata and Taraxacum officinale) and one C3 grass species (Elymus repens)—under 12 experimentally altered temperature and precipitation regimes at the Boston Area Climate Experiment (BACE) in Waltham, Massachusetts. We also measured shifts in foliar C and nitrogen (N) content to determine possible changes in plant C/nutrient balance. We hypothesized that the warming treatment would cause an increase in photosynthesis rates, unless water was limiting; therefore, we expected an interactive effect of warming and precipitation treatments. We found that warming and drought reduced leaf-level photosynthesis most dramatically when environmental or seasonal conditions produced soils that were already dry. In general, the plants transpired fastest when soils were wet and slowest when soils were dry. Drought treatments increased WUE relative to plants in the ambient and wet treatments but only during the driest and warmest background conditions. Leaf N concentration increased with warming, thereby indicating that future warming may cause some plants to take up more soil N and/or allocate more N to their leaves, possibly as consequences of increased nutrient availability. There were no significant interactive effects of the warming and precipitation treatments together across all seasons, indicating that responses were not synergistic or ameliorative.

Do young people benefit from AA as much, and in the same ways, as adult aged 30+? A moderated multiple mediation analysis

BACKGROUND Research has shown that participation in Alcoholics Anonymous (AA) confers significant recovery benefit to adults suffering from alcohol use disorder (AUD). Concerns persist, however, that AA may not work as well for younger adults, who tend to have shorter addiction histories, different social circumstances, and less spiritual/religious interest than adults. METHODS Secondary data analysis of Project MATCH, using a prospective, moderated multiple mediation analysis to test and compare six previously identified mechanisms of change in younger adults (n=266) vs. adults aged 30+ (n=1460). Nine clinical sites within the United States. Treatment-seeking adults (n=1726) suffering from AUD who participated in 12 weeks of outpatient treatment and completed follow-ups at 3-, 9- and 15-months. AA attendance during treatment; mediators at 9 months; and outcomes [percentage of days abstinent (PDA) and drinks per drinking day (DDD)] at 15 months. RESULTS AA attendance was associated with improved drinking outcomes in both younger adults (PDA: F(1, 247)=8.55, p<0.01; DDD: F(1, 247)=15.93, p<0.01) and adults aged 30+ (PDA: F(1, 1311)=86.58, p<0.01; DDD: F(1, 1311)=11.96, p<0.01). Only two of the six hypothesized pathways (i.e., decreases in pro-drinking social networks, self-efficacy in social situations) appeared to work in younger adults. CONCLUSION Unidentified mechanisms of behavior change that are mobilized by AA participation appear to be at work in young people. Once identified, these mechanisms may shed new light on how exactly AA confers similar benefits for young people and, more broadly, may enhance our understanding of recovery-related change for young adults that could yield novel intervention targets.

Examining Trends in Intake Rates, Client Symptoms, Hopelessness, and Suicidality in a University Counseling Center over 12 Years.

The question whether levels of psychopathology and symptom severity among university counseling center client populations are increasing or not has received a great deal of attention in professional psychology. We examined 12-year archival intake records of a university counseling center to test for trends regarding: (a) the overall number of student-clients seeking counseling, (b) the frequency with which specific symptoms were reported, (c) the number of times student-clients reported experiencing hopelessness at various levels of intensity, and (d) the number of times student-clients reported suicide ideation at two levels of intensity. The sample (n = 6,676) was predominantly female (69.2%), White (80.2%), and on average 23.1 years old (SD = 8.0). Individual intake records were converted into monthly counts, which were checked for linear trends over time using autoregressive models. No significant linear trends were found except for a small decreasing trend regarding the number of intake clients reporting advanced suicide ideation (β = –0.019, p = 0.027). Our findings suggest a long-term (i.e., more than 10-year) stability of student-clients’ self-reported symptoms, and corroborate previous findings of short-term (i.e., 5–8 years) stability of client distress at intake over time.

Weight Gain and 10-Year Cardiovascular Risk With Sustained Tobacco Abstinence in Smokers With Serious Mental Illness: A Subgroup Analysis of a Randomized Trial

OBJECTIVE People with serious mental illness die earlier than those without mental illness, largely from cardiovascular disease due to high rates of smoking and obesity. The objective of this study was to determine whether the metabolic effects of postcessation weight gain among smokers with serious mental illness attenuated the cardiovascular benefit of tobacco abstinence. METHOD A subgroup analysis was conducted of 65 outpatient smokers with DSM-IV diagnosis of schizophrenia, schizoaffective disorder, or bipolar disorder from 10 community mental health centers in 6 states who enrolled between March 2008-April 2012 and completed a trial of varenicline for tobacco abstinence. The intervention included a 12-week open-label phase with varenicline followed by a 40-week randomized, placebo-controlled phase in 87 participants who achieved 12-week abstinence. Main outcome measures were smoking status and change from baseline in weight and 10-year Framingham cardiovascular risk score at end of intervention (week 52). RESULTS At week 52, 65 participants completed follow-up (33 abstinent; 32 relapsed). At baseline, the 2 groups did not differ in body mass index (mean = 31 kg/m(2)), blood pressure, serum glucose, or diagnoses of diabetes (31%) and hypertension (34%). Abstinent participants were older and had a higher mean baseline Framingham risk score (14.2% vs 10.3%, P = .002). At week 52, abstinent participants gained more weight than relapsed participants (4.8 vs 1.2 kg, P = .048) and, as a result of quitting smoking, had a greater reduction in Framingham risk score (-7.6% vs 0.0%, P < .001). There was no effect of study drug assignment on weight or Framingham risk score. CONCLUSIONS Sustained tobacco abstinence reduced 10-year cardiovascular risk in outpatients with serious mental illness despite significant postcessation weight gain and high prevalence of obesity, diabetes, and hypertension. TRIAL REGISTRATION Clinicaltrials.gov identifier: NCT00621777.

Early onset marijuana use is associated with learning inefficiencies

OBJECTIVE Verbal memory difficulties are the most widely reported and persistent cognitive deficit associated with early onset marijuana use. Yet, it is not known what memory stages are most impaired in those with early marijuana use. METHOD Forty-eight young adults, aged 18-25, who used marijuana at least once per week and 48 matched nonusing controls (CON) completed the California Verbal Learning Test, Second Edition (CVLT-II). Marijuana users were stratified by age of initial use: early onset users (EMJ), who started using marijuana at or before age 16 (n = 27), and late onset marijuana user group (LMJ), who started using marijuana after age 16 (n = 21). Outcome variables included trial immediate recall, total learning, clustering strategies (semantic clustering, serial clustering, ratio of semantic to serial clustering, and total number of strategies used), delayed recall, and percent retention. RESULTS Learning improved with repetition, with no group effect on the learning slope. EMJ learned fewer words overall than LMJ or CON. There was no difference between LMJ and CON in total number of words learned. Reduced overall learning mediated the effect on reduced delayed recall among EMJ, but not CON or LMJ. Learning improved with greater use of semantic versus serial encoding, but this did not vary between groups. EMJ was not related to delayed recall after adjusting for encoding. CONCLUSIONS Young adults reporting early onset marijuana use had learning weaknesses, which accounted for the association between early onset marijuana use and delayed recall. No amnestic effect of marijuana use was observed. (PsycINFO Database Record

Predictors of tobacco abstinence in outpatient smokers with schizophrenia or bipolar disorder treated with varenicline and cognitive behavioral smoking cessation therapy

BACKGROUND The estimated mortality gap between those with and without serious mental illness (SMI) is increasing, now estimated at 28years, which is largely due to smoking-related diseases. AIMS We sought to identify predictors of 14-day continuous abstinence in stable outpatient smokers with SMI. METHOD Adult smokers with schizophrenia spectrum (n=130) or bipolar disorder (n=23) were enrolled in a 12-week course of varenicline and cognitive-behavioral therapy for smoking cessation. RESULTS Independent predictors of abstinence included reduction in withdrawal symptoms prior to the quit day, fewer cigarettes smoked per day at baseline, better baseline attention, remitted alcohol dependence, and lower expectation of peer support to aid quitting. CONCLUSIONS Interventions that consider these targets may improve smoking cessation outcomes in those with SMI.

Prospective Association between Major Depressive Disorder and Leukocyte Telomere Length over Two Years

BACKGROUND Reduced leukocyte telomere length (LTL) has been found to be associated with multiple common age-related diseases, including heart disease, diabetes, and cancer. A link has also been suggested between shortened LTL and major depressive disorder (MDD), suggesting that MDD may be a disease of accelerated aging. This prospective, longitudinal study examined the association between depression diagnosis at baseline and change in LTL over two years in a well-characterized sample of N = 117 adults with or without MDD at baseline, using rigorous entry criteria. METHODS Participants aged 18-70 were assessed with validated instruments by trained, doctoral-level clinician raters at baseline and at two-year follow-up, and blood samples were obtained at both visits. LTL was assayed under identical methods using quantitative polymerase chain reaction (qPCR). The effect of an MDD diagnosis at baseline on change in LTL over two years was examined via hierarchical mixed models, which included potential confounders. RESULTS Individuals with MDD at baseline had greater LTL shortening over two years than individuals without MDD (p = 0.03), even after controlling for differences in age, sex, and body mass index (BMI). In the sub-sample of individuals with MDD diagnoses at baseline, no significant associations between LTL change and symptom severity or duration were found. CONCLUSION A baseline diagnosis of MDD prospectively predicted LTL shortening over two years. Our results provide further support for MDD as a disease associated with accelerated aging in a well-characterized sample using validated, clinician-rated measures.

The loss of a fellow service member: Complicated grief in post-9/11 service members and veterans with combat-related posttraumatic stress disorder

Bereavement is a potent and highly prevalent stressor among service members and veterans. However, the psychological consequences of bereavement, including complicated grief (CG), have been minimally examined. Loss was assessed in 204 post‐9/11, when service members and veterans with combat‐related posttraumatic stress disorder (PTSD) took part in a multicenter treatment study. Those who reported the loss of an important person completed the inventory of complicated grief (ICG; n = 160). Over three quarters (79.41%) of the sample reported an important lifetime loss, with close to half (47.06%) reporting the loss of a fellow service member (FSM). The prevalence of CG was 24.75% overall, and nearly one third (31.25%) among the bereaved. CG was more prevalent among veterans who lost a fellow service member (FSM) (41.05%, n = 39) compared to those bereaved who did not (16.92%, n = 11; OR = 3.41, 95% CI: 1.59, 7.36). CG was associated with significantly greater PTSD severity, functional impairment, trauma‐related guilt, and lifetime suicide attempts. Complicated grief was prevalent and associated with adverse psychosocial outcomes in veterans and service members with combat‐related PTSD. Clinicians working with this population should inquire about bereavement, including loss of a FSM, and screen for CG. Additional research examining CG in this population is needed.

Warming increases the sensitivity of seedling growth capacity to rainfall in six temperate deciduous tree species

Using a fully factorial precipitation by warming experiment in an old-field ecosystem in the northeastern USA we studied the climatic sensitivity of seedlings of six native tree species. Warm and dry conditions suppressed seedling growth, but affected species differently by increasing mortality, enhancing rates of herbivory or decreasing foliar carbon uptake. Our results indicate that, in the northeastern USA, dry years in a future warmer environment could have damaging effects on the growth capacity of early secondary successional forests, through species-specific effects on leaf production, herbivory and mortality.