Using latent class growth modeling to examine cognitive predictors of suicidal ideation in the elderly

Late life suicide is a serious public health concern. Suicide rates peak in individuals aged 65 or older. Because individuals 65 or older will comprise 20% of the population by 2039, late life suicide is expected to be a growing public health problem. Recent cross sectional studies suggest that deficits in frontal executive functioning, memory and attention are associated with suicidal ideation in the elderly. Our current study is a secondary analysis of data from a clinical trial entitled “Incomplete Response in Late Life Depression: Getting to Remission”. Individuals with major depression received venlafaxine XR monotherapy for depression and were followed repeatedly for up to 16 weeks. We used latent class growth modeling to classify groups of individuals aged > 60 based on trajectories of suicidal ideation. We controlled for time dependent variables (depression and antidepressant doses) and baseline demographics. The optimal model classified individuals into three groups with linear or quadratic trajectories of suicidal ideation. We also ran various analyses using different link functions to find the link that was most appropriate for our data (logistic, censored normal or zero inflated Poisson). After trajectory group membership was determined, we examined whether cognitive dysfunction predicted suicidal ideation trajectory membership using multinomial logistic regression. Using the zero inflated Poisson link latent trajectory model, we determined that having a better score on the Trails B frontal lobe measure was statistically significantly associated with individuals having higher levels of suicidal ideation; however, this association was no longer significant when a multivariable model was used. No statistically significant associations were observed with the other frontal lobe measures, i.e., Trails B/A, Stroop 3 and Stroop 4. In addition, neither individual subscale scores nor total scores from the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) were associated with individuals with having higher trajectories of suicidal ideation. The present study is the first to our knowledge that examines how cognitive status is associated with long-term trajectories of suicidal symptoms in depressed elderly adults

Conversion Hallucinations in a Patient with Pseudohypoparathyroidism

There are few case reports in the literature which discuss psychiatric disturbances in patients with pseudohypoparathyroidism (PH P) (1,2). PHP is a disease characterized by an inadequate response to parathyroid hormone . Often these patients are obese with a short, stocky build and moon-shaped face. Mental retardation is present in as many as 10% of these patients; a reversible dementialike syndrome can also occur (2,3). In addition, Capgras\u27 syndrome has been observed in pseudohypoparathyroid patients (1,2). In these last two reports the authors concluded that the psychosis was probably organically-based. Hay et al (I) noted in their case report that psychotic symptoms were correlated with EEG abnormalities; furthermore, remission of these symptoms was correlated with normalization of the EEG tracing

The neurobiology of neurotensin: focus on neurotensin-dopamine interactions

Neurotensin (NT) is a tridecapeptide which fulfills many of the requisite criteria for a role as a central nervous system (CNS) neurotransmitter. It is closely associated with CNS dopamine neurons and has been shown to interact with dopamine at physiological, anatomical and behavioral levels. Neurotensin is colocalized with dopaminergic neurons in the hypothalamus and midbrain. In addition, it blocks behaviors associated with activation of the dopaminergic pathways. Centrally administered NT has been shown to mimic many of the actions of antipsychotic drugs. In addition, the concentration of NT in cerebrospinal fluid is decreased in patients with schizophrenia. Administration of clinically effective antipsychotic drugs increases concentrations of NT in the caudate nucleus and nucleus accumbens. NT has been shown to play a role in signal transduction by mostly mobilizing calcium stores following inosital phosphate formation. This has been linked to subsequent events in protein phosphorylation. Lipophillic NT receptor agonists may represent a novel approach to the development of a new class of antipsychotic drugs

Neurotensin effects on calcium/calmodulin-dependent protein phosphorylation in rat neostriatal slices

Neurotensin (NT) is an endogenous brain tridecapeptide for which high affinity binding sites exist in the central nervous system. We have investigated the effects of NT incubation with rat neotriatal slices on calcium/calmodulin (Ca/CaM)-dependent protein phosphorylation. Slices were incubated with NT (5 or 50 nM) for 3, 10, 16, or 30 min followed by in vitro phosphorylation, electrophoresis and autoradiography. NT significantly altered the phosphorylation of a 62 kDa protein which is likely the β subunit of the Ca/CaM dependent protein kinase. These changes may reflect the ability of NT to influence calcium mediated signal transduction