Biomedical subjects

Jeffrey P Reiss

Publications and source records attributed to Jeffrey P Reiss.

11 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↗

PubMed2006

Humor perception deficits in schizophrenia.

Humor is a complex cognitive process that could be used to elucidate subtle cognitive deficits. Significant deficits in humor perception were observed among 23 outpatients with schizophrenia compared with 20 controls matched for age, gender and education, using a 128-item humor test.

Adult↗

PubMed2006

Psychosis in multiple sclerosis associated with left temporal lobe lesions on serial MRI scans.

There is retrospective evidence of a correlation between psychosis in multiple sclerosis (MS) patients and temporal lobe pathology. A 35-year-old woman with MS presented with psychosis. There was no concurrent history of medication/substance use or family history. Comparison with previous MRI scans showed significant progression of lesions within the periventricular white matter of the left temporal lobe. This case highlights the association of psychosis and MS progression with worsening of left temporal lobe lesions. Prospective studies are required to ascertain the extent to which left temporal lobe lesions are predictive of future psychosis.

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

Could obsessive-compulsive disorder have originated as a group-selected adaptive trait in traditional societies?

Obsessive-compulsive disorder (OCD) possesses distinctive characteristics inviting evolutionary and anthropological explanations. A genetically based condition with low fecundity persisting through generations is paradoxical. The concept of group selection is an evolutionary principle capable of clarifying the perplexing epidemiology of OCD. Using a group-selection paradigm, the authors propose that OCD reflects an ancient form of behavioural specialization. The majority of compulsions such as checking, washing, counting, needing to confess, hoarding and requiring precision, all carry the potential to benefit society. Focussing primarily on hunting and gathering cultures, the potential evolutionary advantages of OCD are explored.

Adaptation, Biological↗

PubMed2004

Do antipsychotics ameliorate or exacerbate Obsessive Compulsive Disorder symptoms? A systematic review.

BACKGROUND: Paradoxically, some reports in the literature support the use of antipsychotics in the treatment of Obsessive Compulsive Disorder (OCD), while other reports suggest that antipsychotics can exacerbate OCD symptoms. To date, there is no published systematic review of the relationship between OCD symptoms and antipsychotic drugs. METHODS: A Medline and PsychInfo search (1980-2003) was conducted to collect published reports of the interactions between antipsychotics and OCD symptoms. RESULTS: In the treatment of refractory OCD, case series, open label trials and placebo-controlled trials were found suggesting efficacy of antipsychotic augmentation to ongoing antidepressant treatment. In the placebo-controlled trials with haloperidol, risperidone, olanzapine, and quetiapine, a significantly higher response rate (46-71%) was found for the antipsychotic groups, compared to no response for the placebo groups. Reports of exacerbation of OCD symptoms with the use of atypical antipsychotics were limited to individuals with a primary psychotic disorder. LIMITATIONS: Definition of response in most of these treatment studies was based on a modest reduction of OCD symptoms, and no studies were available on long-term efficacy. There were also no published reports that systematically evaluated the incidence of OCD symptoms associated with atypical antipsychotics. CONCLUSIONS: All antipsychotics mentioned above had short-term controlled evidence to support their use as augmenting agents in the treatment of refractory OCD. The suggested management of OCD induction/exacerbation due to atypical antipsychotics is to increase the dose of the atypical antipsychotic and/or add a selective serotonin reuptake inhibitor.

Antidepressive Agents↗

PubMed2003

A Canadian multicenter trial assessing memory and executive functions in patients with schizophrenia spectrum disorders treated with olanzapine.

Serial verbal learning task (explicit long-term memory) and verbal fluency (generation of a response) are tests that are usually severely impaired in schizophrenia. Despite the growing literature supporting the clinical efficacy of olanzapine, psychiatrists still question its cognitive consequences. This study assessed the efficacy of olanzapine on neurocognitive functioning. Patients (N = 134) meeting diagnostic criteria for schizophrenia, schizophreniform, or schizoaffective disorders began an 8-week, open-label olanzapine treatment at a dose of 5 mg/d, which was increased to 10 mg/d after 1 week. Daily dosage was subsequently adjusted between 5 and 20 mg/d based on individual clinical status. All previous antipsychotics were tapered and discontinued during the first 2 weeks of the study. Neuropsychologic assessments were carried out at baseline and at 4 and 8 weeks. Explicit long-term memory was assessed with the Rey Auditory-Verbal Learning Test: the average immediate recall score significantly improved (P < 0.001), as did the delayed recall score (P < 0.001). The average total score on category fluency improved from 34.6 words at baseline to 37.6 words at end point (P < 0.0001). Time on both Trail A and B making tasks significantly decreased (P < 0.0001). Lack of a control arm makes it impossible to exclude a practice effect as an explanation for the enhanced cognitive performance, although the Word List Recall test represents one of the better resources to avoid a practice effect. After switching to olanzapine, there was a statistically significant improvement of cognitive function in the 3 main domains tested and no significant worsening of any memory or executive function measure.

Acoustic Stimulation↗

PubMed2003

Evolutionary perspectives on schizophrenia.

The theory of evolution may be relevant to psychiatric disorders. Evolution reflects changes in genes throughout time. Thus, evolutionary forces can shape any phenotype that is genetically rooted and that possesses a long history. Schizophrenia is likely an ancient condition with a substantial genetic component. Since the 1960s, several researchers have applied evolutionary principles to the study of schizophrenia. In general, schizophrenia is either viewed as an evolutionary advantageous condition or as a disadvantageous byproduct of normal brain evolution. This paper reviews major evolutionary explanations--historical and current--that speculate on the possible origins of schizophrenia.

Biological Evolution↗

PubMedDate not supplied

Genital anaesthesia persisting six years after sertraline discontinuation.

Sexual side-effects, in general, are common with selective serotonin-reuptake inhibitors (SSRIs). Genital anaesthesia is a rare side-effect previously described with sertraline and fluoxetine use. With SSRI discontinuation, the sexual side-effects are expected to resolve. We report a case of a 26-year-old male who experienced genital anaesthesia during sertraline treatment and continued to be symptomatic despite medication discontinuation 6 years previously. To date, there have been no published reports of SSRI-induced sexual side-effects persisting beyond SSRI discontinuation. This case highlights the complex interplay of psychopharmacologic and psychodynamic factors that can occur in patients with sexual dysfunction.

Adult↗