Dietary specialization is linked to reduced species durations in North American fossil canids.

How traits influence species persistence is a fundamental question in ecology, evolution and palaeontology. We test the relationship between dietary traits and both species duration and locality coverage over 40 million years in North American canids, a clade with considerable ecomorphological disparity and a dense fossil record. Because ecomorphological generalization-broad resource use-may enable species to withstand disturbance, we predicted that canids of average size and mesocarnivory would exhibit longer durations and wider distributions than specialized larger or smaller species. Second, because locality coverage might reflect dispersal ability and/or survivability in a range of habitats, we predicted that high coverage would correspond with longer durations. We find a nonlinear relationship between species duration and degree of carnivory: species at either end of the carnivory spectrum tend to have shorter durations than mesocarnivores. Locality coverage shows no relationship with size, diet or duration. To test whether generalization (medium size, mesocarnivory) corresponds to an adaptive optimum, we fit trait evolution models to previously generated canid phylogenies. Our analyses identify no single optimum in size or diet. Instead, the primary model of size evolution is a classic Cope's Rule increase over time, while dietary evolution does not conform to a single model.

Psychiatric context of human immunodeficiency virus infection among former plasma donors in rural China.

BACKGROUND: China's HIV epidemic commenced in its agrarian provinces through contaminated commercial plasma donation centers and is now becoming a public health concern nationwide. Little is known of the psychiatric and substance use disorder characteristics of this population, or their impact on everyday function, employment, and life quality. METHODS: HIV-infected (HIV+) former plasma donors (N=203) and HIV-negative (HIV-) donor controls (N=198) completed the World Mental Health Survey Composite International Diagnostic Interview to determine lifetime major depressive disorder (MDD), substance use disorders, and suicidality. Current mood and suicidality were assessed with the Beck Depression Inventory-II. Everyday function was measured by an Activity of Daily Living questionnaire; life quality was evaluated by the Medical Outcomes Study-HIV. RESULTS: HIV+ participants had known their infected status for 2 years on average. Most were taking antiretroviral treatment and had frank AIDS. Rates of current MDD were similar across groups (1-2%), but HIV+ had a higher frequency of lifetime MDD (14% vs. 5%, p<.05). Its onset preceded date of known infection in one-third of cases. Alcoholism was the only substance use disorder detected; HIV+ had a higher proportion of lifetime substance use diagnoses (14% vs. 6%, p<.05). Depression and AIDS independently predicted worse daily functioning and life quality, and unemployment. LIMITATIONS: The epicenter of China HIV has moved into urban injection drug users, limiting the representativeness of this sample. CONCLUSIONS: High rates of MDD and its impact suggest that in China, as elsewhere, comprehensive care requires detection and treatment of mood disorder.

Methamphetamine use parameters do not predict neuropsychological impairment in currently abstinent dependent adults.

Methamphetamine (meth) abuse is increasingly of public health concern and has been associated with neurocognitive dysfunction. Some previous studies have been hampered by background differences between meth users and comparison subjects, as well as unknown HIV and hepatitis C (HCV) status, which can also affect brain functioning. We compared the neurocognitive functioning of 54 meth dependent (METH+) study participants who had been abstinent for an average of 129 days, to that of 46 demographically comparable control subjects (METH-) with similar level of education and reading ability. All participants were free of HIV and HCV infection. The METH+ group exhibited higher rates of neuropsychological impairment in most areas tested. Among meth users, neuropsychologically normal (n=32) and impaired (n=22) subjects did not differ with respect to self-reported age at first use, total years of use, route of consumption, or length of abstinence. Those with motor impairment had significantly greater meth use in the past year, but impairment in cognitive domains was unrelated to meth exposure. The apparent lack of correspondence between substance use parameters and cognitive impairment suggests the need for further study of individual differences in vulnerability to the neurotoxic effects of methamphetamine.

Psychiatric context of acute/early HIV infection. The NIMH Multisite Acute HIV Infection Study: IV.

Acute/early HIV infection is a period of high risk for HIV transmission. Better understanding of behavioral aspects during this period could improve interventions to limit further transmission. Thirty-four participants with acute/early HIV infection from six US cities were assessed with the Mini International Diagnostic Interview, Beck Depression Inventory II, State-Trait Anxiety Inventory, Brief COPE, and an in-depth interview. Most had a pre-HIV history of alcohol or substance use disorder (85%); a majority (53%) had a history of major depressive or bipolar disorder. However, post-diagnosis coping was predominantly adaptive, with only mild to moderate elevations of anxious or depressive mood. Respondents described challenges managing HIV in tandem with pre-existing substance abuse problems, depression, and anxiety. Integration into medical and community services was associated with adaptive coping. The psychiatric context of acute/early HIV infection may be a precursor to infection, but not necessarily a barrier to intervention to reduce forward transmission of HIV among persons newly infected.

Lack of understanding of acute HIV infection among newly-infected persons-implications for prevention and public health: The NIMH Multisite Acute HIV Infection Study: II.

Acute/early HIV infection is a period of high HIV transmission. Consequently, early detection of HIV infection and targeted HIV prevention could prevent a significant proportion of new transmissions. As part of an NIMH-funded multisite study, we used in-depth interviews to explore understandings of acute HIV infection (AHI) among 34 individuals diagnosed with acute/early HIV infection in six US cities. We found a marked lack of awareness of AHI-related acute retroviral symptoms and a lack of clarity about AHI testing methods. Most participants knew little about the meaning and/or consequences of AHI, particularly that it is a period of elevated infectiousness. Over time and after the acute stage of infection, many participants acquired understanding of AHI from varied sources, including the Internet, HIV-infected friends, and health clinic employees. There is a need to promote targeted education about AHI to reduce the rapid spread of HIV associated with acute/early infection within communities at risk for HIV.

Transition from acute to chronic pain and disability: a model including cognitive, affective, and trauma factors.

This study evaluated a theoretically and empirically based model of the progression of acute neck and back pain to chronic pain and disability, developed from the literature in chronic pain, cognition, and stress and trauma. Clinical information and standardized psychosocial measures of cumulative traumatic events exposure (TLEQ), depressed mood (CES-D), pain (DDS), physical disability (PDI), and pain beliefs (PBPI) were collected at baseline from 84 acute back pain patients followed at an Acute Back Clinic over 3 months. Path analysis was used for the longitudinal prediction of perceived pain and disability. The predictive model accounted for 26% of the variance in persistent pain intensity and 58% of the variance in perceived physical disability at 3 months. Greater exposure to past traumatic life events and depressed mood were most predictive of chronic pain; depressed mood and negative pain beliefs were most predictive of chronic disability. More cumulative traumatic life events, higher levels of depression in the early stages of a new pain episode, and early beliefs that pain may be permanent significantly contribute to increased severity of subsequent pain and disability. Replication in a larger sample is desirable to confirm these paths. Early detection of elevated depressive symptoms and high trauma exposure may identify individuals at greater risk for developing chronic pain syndromes who may benefit from early multidisciplinary intervention.

Is hepatitis C infection associated with increased risk of depression in persons with methamphetamine dependence?

The abuse of methamphetamine (MA) has increased in the United States over the past 15 years and is associated with considerable negative social, psychological, and health effects, including symptoms of depression. Infection with the hepatitis C virus (HCV), which is independently associated with increased risk of depression, is common among MA users, possibly due to high rates of transmission risk behaviors in this cohort (eg, injection drug use). Given the prevalence of depression among HCV-infected individuals and MA users separately, the current study aimed to determine whether HCV infection and MA dependence are associated with additive effects on depression. Focused psychiatric evaluations were conducted on 39 individuals with both MA dependence and HCV infection (MA + HCV +), 57 persons with only MA dependence (MA + HCV -), and a comparison sample of 46 participants with neither risk factor (MA - HCV -). Consistent with prior research, greater self-reported symptoms of depression were observed in the MA + groups relative to MA - HCV - participants; however, there was no evidence to suggest an additive effect of HCV infection. Surprisingly, the prevalence of current and lifetime diagnoses of Major Depressive Disorder (MDD) did not differ across the study groups. Results from this study suggest that HCV infection does not confer an additive effect on the severity of depressive symptoms or the prevalence of major depression in persons with MA dependence.

Effects of human immunodeficiency virus and methamphetamine on cerebral metabolites measured with magnetic resonance spectroscopy.

Human immunodeficiency virus (HIV) and methamphetamine (METH) use disorders are associated with cerebral dysfunction. To determine whether these effects were evident on in vivo neuroimaging, quantitative, single voxel magnetic resonance (MR) spectroscopy was used to assess frontal white matter, frontal gray matter, and basal ganglia in 40 HIV+/METH+, 66 HIV+/METH-, 48 HIV-/METH+, and 51 HIV-/METH- participants. HIV was associated with lower N-acetylaspartate (NAA) in frontal white and frontal gray matter but METH was not associated with cerebral metabolite differences in any region. Among HIV+ individuals, lower CD4 counts and higher plasma HIV viral loads were associated with lower NAA in frontal gray matter and basal ganglia. The relationship between detectable plasma HIV viral load and NAA in frontal white matter was significantly stronger in the HIV+/METH+ group, compared to HIV+/METH-. Higher detectable plasma HIV viral load was significantly associated with higher myo-inositol (MI) in frontal white and gray matter for HIV+/METH+, but not HIV+/METH-. For the HIV-/METH+ group, lifetime duration of METH use was associated with higher choline levels in frontal gray matter and higher MI levels in basal ganglia. Our findings are consistent with significant disruption of neuronal integrity in the frontal lobes of HIV-infected individuals. Although METH was not associated with cerebral metabolite levels, other findings suggested that METH use did affect the brain. For example, the relationship between detectable plasma HIV viral load and NAA levels was limited to HIV+/METH+ individuals. This evidence indicates when HIV is poorly suppressed, METH may modify the effects of the virus on neuronal integrity.