Biomedical subjects

Darren W Campbell

Publications and source records attributed to Darren W Campbell.

7 recordsLinked to original sources

PubMed2006

Time-varying amygdala response to emotional faces in generalized social phobia.

BACKGROUND: Individuals with social phobia (SP) have altered behavioral and neural responses to emotional faces and are hypothesized to have deficits in inhibiting emotion-related amygdala responses. We tested for such amygdala deficits to emotional faces in a sample of individuals with SP. METHOD: We used functional magnetic resonance imaging (fMRI) to examine the neural substrates of emotional face processing in 14 generalized SP (gSP) and 14 healthy comparison (HC) participants. Analyses focused on the temporal dynamics of the amygdala, prefrontal cortex (PFC), and fusiform face area (FFA) across blocks of neutral, fear, contempt, anger, and happy faces in gSP versus HC participants. RESULTS: Amygdala responses in participants with gSP occurred later than the HC participants to fear, angry, and happy faces. Parallel PFC responses were found for happy and fear faces. There were no group differences in temporal response patterns in the FFA. CONCLUSIONS: This finding might reflect a neural correlate of atypical orienting responses among individuals with gSP. Commonly reported SP deficits in habituation might reflect neural regions associated with emotional self-evaluations rather than the amygdala. This study highlights the importance of considering time-varying modulation when examining emotion-related processing in individuals with gSP.

Adult↗

PubMed2006

Striatal function in generalized social phobia: a functional magnetic resonance imaging study.

BACKGROUND: Although evidence suggests the involvement of the amygdala in generalized social phobia (GSP), few studies have examined other neural regions. Clinical, preclinical, and dopamine receptor imaging studies demonstrating altered dopaminergic functioning in GSP suggest an association with striatal dysfunction. This is the first functional magnetic resonance imaging (fMRI) study to use a cognitive task known to involve the striatum to examine the neural correlates of GSP. We examined whether subjects with GSP had differential activation in striatal regions compared with healthy control subjects while engaged in a cognitive task that has been shown to activate striatal regions reliably. METHODS: Ten adult, unmedicated subjects with a primary DSM-IV diagnosis of GSP and 10 age-, gender-, and education-matched healthy comparison subjects underwent fMRI while performing the implicit sequence learning task. RESULTS: The GSP and healthy comparison subjects did not differ significantly on the behavioral performance of the task. Subjects with GSP, however, had significantly reduced neural activation related to implicit learning compared with healthy comparison subjects in the left caudate head, left inferior parietal lobe, and bilateral insula. CONCLUSIONS: These findings support the hypothesis that GSP is associated with striatal dysfunction and further the neurobiological understanding of this complex anxiety disorder.

Adult↗

PubMed2006

Deficit in schizophrenia to recruit the striatum in implicit learning: a functional magnetic resonance imaging investigation.

In schizophrenia, explicit learning deficits have been well established although it is less clear whether these patients have deficits in implicit learning (IL). IL is thought to depend on intact striatal functioning. This study examined the hypothesis that schizophrenia patients show deficient recruitment of striatal activation during an IL paradigm, relative to performance-matched healthy comparison subjects. Ten subjects with schizophrenia on atypical antipsychotic medication and 10 age, gender, education, and performance matched healthy comparison subjects underwent fMRI while performing an IL task. On the basis of whole-brain and striatal region-of-interest analyses, we found a relative lack of striatal activation in schizophrenia patients. This result is consistent with convergent evidence of striatal dysfunction in schizophrenia.

Adult↗

PubMed2005

The role of the striatum in implicit learning: a functional magnetic resonance imaging study.

Previous research has posited striatal involvement in implicit learning. However, imaging studies have not directly compared learners with non-learners. Using functional magnetic resonance imaging with 15 study participants, we used an implicit learning task previously associated with striatal recruitment. Dorsal and ventral striatum activation was observed in the eight participants who demonstrated implicit learning. Ventral striatum activations occurred to a greater extent in implicit learning versus non-implicit learning participants, and were correlated with the degree of reaction time advantage in implicit learning participants, even after controlling for general decreases in reaction time over time. These findings strengthen the specificity of the striatum in implicit learning and are suggestive of a dissociation of striatal regions relative to elements of implicit learning performance.

Adolescent↗

PubMed2005

The relation between perceived need for mental health treatment, DSM diagnosis, and quality of life: a Canadian population-based survey.

OBJECTIVES: Prevalence estimates of mental disorders were designed to provide an indirect estimate of the need for mental health services in the community. However, recent studies have demonstrated that meeting criteria for a DSM-based disorder does not necessarily equate with need for treatment. The current investigation examined the relation between self-perceived need for mental health treatment and DSM diagnosis, with respect to quality of life (QoL) and suicidal ideation. METHODS: Data came from an Ontario population-based sample of 8116 residents (aged 15 to 64 years). The University of Michigan Composite International Diagnostic Interview was used to diagnose mood, anxiety, substance use, and bulimia disorder according to DSM-III-R criteria. We categorized past-year help seeking for emotional symptoms and (or) perceiving a need for treatment without seeking care as self-perceived need for treatment. We used a range of variables to measure QoL: self-perception of mental health status, a validated instrument that measured well-being, and restriction of activities (current, past 30 days, and long-term). RESULTS: Independent of subjects' meeting criteria for a DSM-III-R diagnosis, self-perceived need for treatment was significantly associated with poor QoL (on all measures) and past-year suicidal ideation. CONCLUSIONS: Self-perceived need for mental health treatment, in addition to DSM diagnosis, may provide valuable information for estimating the number of people in the population who need mental health services. The relation between self-perceived need for treatment and objective measures of treatment need requires future study.

Activities of Daily Living↗

PubMed2004

Stability in perceived control: implications for health among very old community-dwelling adults.

OBJECTIVE: Our purpose was to examine how stability/variability in perceptions of control (PC) relate to a variety of health-related variables. DESIGN: PC stability/variability across multiple domains was assessed in a longitudinal design including 318 adults, 72 to 99 years of age. METHOD: PC and health-related measures were obtained during in-person interviews conducted approximately 3 months apart. PC variability was assessed in relation to self-reported health outcomes (perceived health, chronic health conditions, functional status) and objective measures of physician visits and hospitalizations recorded over a 4-year period in a highly reliable and comprehensive database. RESULTS: PC variability was associated with poorer health, poorer functional status, and more physician visits and hospital admissions, even after statistically controlling for mean PC level and direction-of-change in PC. IMPLICATIONS: Our findings suggest that health and well-being among very old individuals may be compromised by fluctuating levels of PC, or conversely, that stability in PC enhances health.

Aged↗

PubMed2004

A longitudinal analysis of discrete negative emotions and health-services use in elderly individuals.

OBJECTIVE: To test the hypothesis that everyday, discrete negative emotions-anger, frustration, sadness, and fear-relate to health-service use in later life. METHOD: Community-dwelling adults (n = 345) ages 72 to 99 were interviewed about the frequency of recently experienced emotions. Physician visits and hospital admissions in the subsequent 2 years were outcomes. Covariates included prior use of health services, chronic illness, functional status, and demographics. RESULTS: Age, education, and gender moderated relations between negative emotions and health care use. More frustration was associated with fewer physician visits among older individuals. Sadness was associated with more hospital admissions for women. Among those with more education, frequent anger was associated with more physician visits. Projected effects of negative emotions resulted in increases in health-service use, ranging from 18% to 33%. DISCUSSION: The interactions indicate the importance of negative emotions and the larger social and developmental context in health care services use among elderly individuals.

Aged↗