Anthony O. Ahmed

Latent structure of psychotic experiences in the general population

Ahmed AO, Buckley PF, Mabe PA. Latent structure of psychotic experiences in the general population.

Dysregulation of estrogen receptor beta (ERβ), aromatase (CYP19A1), and ER co-activators in the middle frontal gyrus of autism spectrum disorder subjects

BackgroundAutism spectrum disorders (ASD) are much more common in males than in females. Molecular alterations within the estrogen receptor (ER) signaling pathway may contribute to the sex difference in ASD, but the extent of such abnormalities in the brain is not known.MethodsPostmortem middle frontal gyrus tissues (13 ASD and 13 control subjects) were used. The protein levels were examined by western blotting. The gene expression was determined by qRT-PCR.ResultsGene expression analysis identified a 35% decrease in ERβ mRNA expression in the middle frontal gyrus of ASD subjects. In addition, a 38% reduction in aromatase (CYP19A1) mRNA expression was observed in ASD subjects. We also found significant decreases in ER co-activators that included a 34% decrease in SRC-1, a 77% decrease in CBP, and a 52% decrease in P/CAF mRNA levels in ASD subjects relative to controls. There were no differences in the mRNA levels of TIF-2, AIB-1 (ER co-activators), ER co-repressors (SMRT and nCoR) and ERα in the middle frontal gyrus of ASD subjects as compared to controls. We observed significant correlations between ERβ, CYP19A1, and co-activators in the study subjects. Immunoblot analysis further confirmed the changes in ERβ and aromatase at the protein level in the control and ASD subjects.ConclusionsThese results, for the first time, provide the evidence of the dysregulation of ERβ and co-factors in the brain of subjects with ASD.

Peers and Peer-Led Interventions for People with Schizophrenia

This article provides a snapshot of the nature, guiding philosophy, and empiric status of interventions for people with schizophrenia that go beyond traditional psychopharmacological and psychosocial treatments to include peer-led interventions. The authors discuss the nature and principles of peer-led interventions for people with schizophrenia and the types of peer-led interventions along with evidence of their effectiveness in fostering the recovery of people with schizophrenia and other severe mental illnesses. Focus is on 3 types of peer-led interventions: (1) mutual support/self-help, (2) consumer-operated services, and (3) peer support services.

Does a Latent Class Underlie Schizotypal Personality Disorder? Implications for Schizophrenia

Despite growing enthusiasm for dimensional models of personality pathology, the taxonic versus dimensional status of schizotypal personality disorder (PD) remains a point of contention in modern psychiatry. The current study aimed to determine empirically the latent structure of schizotypal PD. We examined the latent structure of schizotypal PD in the Psychiatric Morbidity Survey in Great Britain and the second wave of the U.S.-based National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) survey. We analyzed composite indicators created from participant responses using the mean above minus mean below a cut (MAMBAC), Maximum Covariance (MAXCOV), and latent mode factor analysis (L-Mode) taxometric procedures. We also analyzed item-level responses using two latent variable mixture models--latent class analysis and latent class factor analysis. Taxometric and latent variable mixture analyses supported a dimensional, rather than taxonic, structure in both epidemiological samples. The dimensional model better predicted psychosis, intellectual functioning, disability, and treatment seeking than the categorical model based on DSM-IV diagnosis. People meeting criteria for schizotypal PD appear to exist on a spectrum of severity with the rest of the population. The possible dimensionality of schizotypal PD adds to growing support for a dimensional structure of PDs including other Cluster A disorders.

The latent structure of alcohol use pathology in an epidemiological sample

Whether alcohol use pathology is more accurately conceptualized as a categorical construct, or as existing along a dimension remains an open question. Previous investigations of the latent structure of alcohol use pathology have yielded mixed results. The present study used a sample (N = 43,093) drawn from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) of the National Institute on Alcohol Abuse and Alcoholism. A factor analysis of items drawn from the Alcohol Consumption, Alcohol Abuse/Dependence (Alcohol Experiences), and Alcohol Treatment Utilization sections of the NESARC yielded three factors, labeled Functional Disturbance, Tolerance, and Frequency, which were used as indicators in a series of taxometric analyses. These analyses converged on a low base rate alcohol pathology taxon. The relevance of these findings for the diagnosis, etiology, further research, and treatment of alcohol use disorders is discussed.

Taxometric Analyses of Paranoid and Schizoid Personality Disorders

There remains debate about whether personality disorders (PDs) are better conceptualized as categorical, reflecting discontinuity from normal personality; or dimensional, existing on a continuum of severity with normal personality traits. Evidence suggests that most PDs are dimensional but there is a lack of consensus about the structure of Cluster A disorders. Taxometric methods are adaptable to investigating the taxonic status of psychiatric disorders. The current study investigated the latent structure of paranoid and schizoid PDs in an epidemiological sample (N=43,093) drawn from the National Epidemiological Survey on Alcohol and Related Conditions (NESARC) using taxometric analyses. The current study used taxometric methods to analyze three indicators of paranoid PD - mistrust, resentment, and functional disturbance - and three indicators of schizoid PD - emotional detachment, social withdrawal, and functional disturbance - derived factor analytically. Overall, taxometrics supported a dimensional rather than taxonic structure for paranoid and schizoid PDs through examination of taxometric graphs and comparative curve fit indices. Dimensional models of paranoid and schizoid PDs better predicted social functioning, role-emotional, and mental health scales in the survey than categorical models. Evidence from the current study supports recent efforts to represent paranoid and schizoid PDs as well as other PDs along broad personality dimensions.

Latent Structure of Unipolar and Bipolar Mood Symptoms

Ahmed AO, Green BA, Clark CB, Stahl KC, McFarland ME. Latent structure of unipolar and bipolar mood symptoms. u2028Bipolar Disord 2011: 13: 522–536.

A psychometric study of recovery among Certified Peer Specialists

The recovery model is wielding a welcome influence in the mental healthcare system. Despite its potential impact, systematic studies of the recovery construct as viewed by consumers and former consumers of mental health services have only recently begun to permeate the literature. We have embarked on an ongoing collaboration with the Georgia Mental Health Consumer Network to study the recovery experiences of Certified Peer Specialists (CPSs). As a first step, we evaluated the psychometric characteristics of a new measure of the recovery construct in CPSs. CPSs (N=84) enrolled in the GMHCN completed the Maryland Assessment of Recovery in Serious Mental Illness (MARS) along with measures of resilience, coping styles, community living, social support, internalized stigma, psychopathology, and personality. Recovery as measured by the MARS was associated with resilience, coping behaviors, quality of social support, community living, internalized stigma, and severity of psychopathology. Recovery did not demonstrate a statistically significant association with personality. Recovery appeared to mediate the effect of psychopathology and episodic stressors on community functioning. Our psychometric study supports the psychometric soundness of the MARS and the construct validity of recovery.

Latent structure of intermittent explosive disorder in an epidemiological sample

Intermittent explosive disorder (IED) is characterized by distinct periods of impulsive aggression marked by assaultive acts or destruction of property. However, impulsive aggression is also a feature of other disorders, all of which are viewed in diagnostic nomenclature as qualitatively distinct from IED. This state of affairs is problematic for categorical models unless it is demonstrated empirically that IED-related impulsive aggression is qualitatively distinct from impulsive aggression observable in other axis I and II disorders. The current study addresses this question using taxometric methods to examine the latent structure of IED. Participants were respondents on the Collaborative Psychiatric Epidemiological Surveys, which obtained data on a range of disorders including intermittent explosive disorder (N=20,013) and a range of psychological variables. Indicator variables used were drawn from the survey items and submitted to select taxometric methods (MAMBAC and MAXEIG) to determine the relative fits of a taxonic versus dimensional model. The results of taxometric analyses provided support for a taxonic, rather than dimensional, structure for IED symptoms in the epidemiological sample. Taxon group membership was associated with treatment seeking, family history of anger attacks, lower age of onset of anger attacks, and male biological sex, providing strong support for the validity of the IED taxon.

Psychopharmacological Treatment of Neurocognitive Deficits in People with Schizophrenia: A Review of Old and New Targets

Neurocognitive impairments significantly contribute to disability and the overall clinical picture in schizophrenia spectrum disorders. There has therefore been a concerted effort, guided by the discovery of neurotransmitter and synaptic systems in the central nervous system, to develop and test compounds that may ameliorate neurocognitive deficits. The current article summarizes the results of efforts to test neurocognitive-enhancing agents in schizophrenia. Overall, existing clinical trials provide little reason to be enthusiastic about the benefits of psychopharmacological agents at enhancing neurocognition in schizophrenia—a state of affairs that may reflect the inadequacy of single neurotransmitter or receptor models. The etiologic and phenomenological complexity of neurocognitive deficits in schizophrenia may be better served by psychopharmacological agents that (i) target neurotransmitter systems proximal in the causal chain to neurocognitive deficits; (ii) enhance distal survival processes in the central nervous system—neurogenesis, neuronal growth, synaptogenesis, and connectivity; and (iii) counteract the negative effects of aberrant neurodevelopment in schizophrenia, such as neuroinflammation and oxidative stress. Future efforts to develop psychopharmacological agents for neurocognitive impairment in schizophrenia should reflect the knowledge of its complex etiology by addressing aberrations along its causal chain. Clinical trials may benefit methodologically from (i) an appreciation of the phenomenological heterogeneity of neurocognitive deficits in schizophrenia; (ii) a characterization of the predictors of treatment response; and (iii) a recognition of issues of sample size, statistical power, treatment duration, and dosing.