Hippocampal to pituitary volume ratio: a specific measure of reciprocal neuroendocrine alterations in alcohol dependence

Pituitary Volumes Are Reduced in Patients With Alcohol Use Disorder

AIMS

To determine whether there is a difference in pituitary gland volumes in patients with alcohol use disorder compared to healthy people.

METHODS

The subjects included in the study consisted of 15 individuals who met the criteria for alcohol use disorder according to the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM 5) diagnostic criteria based on the Structured Clinical Interview for DSM 5 and were admitted to Firat University School of Medicine, Department of Psychiatry, or were hospitalized, and 17 healthy controls. The volumes of pituitary were measured in subjects.

RESULTS

Absolute pituitary gland volumes of patients with alcohol use disorder and healthy controls were compared in the analysis performed using the independent samples t-test. The mean volume of the patient group was significantly smaller than the healthy controls (58.02 ± 7.24 mm3 in patients with alcohol use disorder vs. 83.08 ± 12.11 mm3, P < 0.01), a difference which persisted after controlling for age, gender and total brain size.

CONCLUSIONS

Patients with alcohol use disorder in this study had smaller pituitary gland volumes compared to those of healthy control subjects. However, this study has limitations including small sample size and not adjusting for previous or current medication use or current anxiety and depression.

Pituitary volume and clinical trajectory in young relatives at risk for schizophrenia

BACKGROUND

Stress and vulnerability likely interact to play a major role in psychosis. While much has been written about the neural diathesis-stress model in psychosis and its clinical risk states, little is known about HPA axis biomarkers in non-help-seeking individuals at familial high risk (FHR). We sought to prospectively measure pituitary volume (PV) in adolescents and young adults at FHR for schizophrenia and to follow their emerging sub-clinical psychotic symptoms and clinical trajectories.

METHOD

Forty healthy controls and 38 relatives of patients with schizophrenia or schizoaffective disorder were identified in Pittsburgh, USA. PV was derived from baseline 1.5 T magnetic resonance imaging. Chapman's schizotypy scales were acquired at baseline, and structured clinical interviews for DSM-IV-TR Axis I diagnoses were attempted annually for up to 3 years.

RESULTS

Seven individuals converted to psychosis. PV did not differ between FHR and control groups overall. Within the FHR group, PV was positively correlated with Chapman's positive schizotypy (Magical Ideation and Perceptual Aberration) scores, and there was a significant group × PV interaction with schizotypy. PV was significantly higher in FHR subjects carrying any baseline Axis I diagnosis (p = 0.004), and higher still in individuals who went on to convert to psychosis (p = 0.0007).

CONCLUSIONS

Increased PV is a correlate of early positive schizotypy, and may predict trait vulnerability to subsequent psychosis in FHR relatives. These preliminary findings support a model of stress-vulnerability and HPA axis activation in the early phases of psychosis.

Pituitary gland in psychiatric disorders: a review of neuroimaging findings

In this paper, it was reviewed neuroimaging results of the pituitary gland in psychiatric disorders, particularly schizophrenia, mood disorders, anxiety disorders, and somatoform disorders. The author made internet search in detail by using PubMed database including the period between 1980 and 2012 October. It was included in the articles in English, Turkish and French languages on pituitary gland in psychiatric disorders through structural or functional neuroimaging results. After searching mentioned in the Methods section in detail, investigations were obtained on pituitary gland neuroimaging in a variety of psychiatric disorders. There have been so limited investigations on pituitary neuroimaging in psychiatric disorders including major psychiatric illnesses like schizophrenia and mood disorders. Current findings are so far from the generalizability of the results. For this reason, it is required to perform much more neuroimaging studies of pituitary gland in all psychiatric disorders to reach the diagnostic importance of measuring it.

Memory impairment associated with neurometabolic abnormalities of the hippocampus in patients with non-neuropsychiatric systemic lupus erythematosus

Objective: Memory impairment is common in patients with systemic lupus erythematosus (SLE). This study examined hippocampal volumes and neurometabolic alterations in relation to memory function in SLE patients without a history of neuropsychiatric syndromes (nonNPSLE).

Methods: Subjects included 81 nonNPSLE patients and 34 healthy controls. Volumetric magnetic resonance imaging and magnetic resonance spectroscopy of the right and left hippocampal areas (RH, LH) were performed. Verbal and visual memory tests were administered and a Memory Impairment Index (MII) was derived from standardized tests.

Results: Higher memory impairment (MII) was correlated with lower RH glutamate + glutamine/creatine ( p = 0.009) and lower RH N-acetylaspartic acid/creatine ( p = 0.012) in nonNPSLE patients. A trend for a negative correlation between RH and LH volumes and MII was evident for absolute hippocampal volumes. Lower RH glutamate + glutamine/creatine was also correlated with worse performance in a mean visual memory index ( p = 0.017).

Conclusions: An association between reduced memory and lower N-acetylaspartic acid/creatine in the RH suggests neuronal damage in nonNPSLE patients with very mild and early disease. Alterations in glutamate + glutamine/creatine further indicate early metabolic changes in nonNPSLE are related to memory impairment, a finding that might suggest that memory impairment relates to presynaptic glutamatergic dysfunction in the hippocampus.

Volume of the adrenal and pituitary glands in depression

Numerous studies have shown that the hypothalamic-pituitary-adrenal (HPA) axis is hyperactive in some depressed patients. It is unclear whether such hyperactivity results in changed volumes of the adrenal glands, pituitary gland and hypothalamus. We systematically reviewed all controlled studies on the adrenal or pituitary glands or hypothalamus volume in unipolar depressive disorder published in PubMed 1966 to December 2009. We identified three studies that investigated the volume of the adrenal glands and eight studies that examined the volume of the pituitary gland, but no studies on hypothalamus were found. Two out of three studies found a statistically significant increase in adrenal volume in patients compared to controls. Four out of eight studies found a statistically significant increase in pituitary volume in patients compared to controls. Different methodological problems were identified such as small population samples, different subtypes of depression and insufficient matching of patients and controls. Due to large heterogeneity of study designs and data, it was futile to make a meta-analysis. It is concluded that it remains unclear whether hyperactivity of the HPA axis results in enlarged adrenal and pituitary glands and it is suggested that prospective studies should be conducted with scanning during successive depressive episodes and periods of remission.

Pituitary volumes in relatives of bipolar patients: high-risk study

BACKGROUND

Increased, decreased, as well as unchanged pituitary volumes have been reported in bipolar disorders (BD). It is unclear, whether abnormal pituitary volumes increase vulnerability for BD (primary vulnerability marker), or are secondary to burden of illness. To address this question, we performed the first high-risk study of pituitary volumes in affected and unaffected relatives of bipolar subjects.

METHOD

High-risk participants (age range 15-30 years) were recruited from families multiply affected with BD and included 24 unaffected, 19 affected subjects with first or second degree bipolar I or II relative, matched by age and sex with 31 controls without a personal or family history of psychiatric disorders. Pituitary volumes were measured on 1.5 T 3D anatomical MRI images using standard methods.

RESULTS

We found comparable pituitary volumes among unaffected, affected relatives of bipolar patients and controls. There were no differences in pituitary volumes between male and female subjects nor was there any sex by group interaction. Analyzing 26 participants with bipolar I parent or excluding 5 medicated subjects did not change the results. There were no differences between subjects from families containing bipolar I versus families containing only bipolar II subjects.

CONCLUSIONS

The lack of abnormalities in unaffected and also affected subjects early in the course of illness in our study, as well as previous investigations of bipolar and familial unipolar children and adolescents, suggest that pituitary volume abnormalities are unlikely to be a primary risk factor for mood disorders.

Pituitary volume in psychosis: the first review of the evidence

The pituitary gland regulates hypothalamic-pituitary-adrenal (HPA) axis activity by secreting adrenocorticotropic hormone (ACTH), and HPA axis abnormalities have been described in psychosis. Moreover, the pituitary gland secretes prolactin, and some antipsychotics increase the secretion of this hormone. Therefore, it is possible that psychosis is associated with an abnormal volume of the pituitary, as a consequence of a dysfunction in either or both these hormonal systems. The present review of the studies conducted so far clearly indicates that the pituitary is a dynamic organ, which changes differently at different stages of the psychotic disorder, in response to both the disorder itself and the treatment with antipsychotics. Specifically, the pituitary is larger in the months immediately preceding or following the psychosis onset, independently from antipsychotic treatments. However, following this initial enlargement, the pituitary tends to become smaller, as suggested by studies in patients with psychosis of at least two years of duration. On top of these dynamic changes that are linked to the course of the disorder, antipsychotics, and especially antipsychotics inducing hyperprolactinaemia, exert additional enlarging effects on pituitary volume. We suggest that the increased pituitary volume associated with the development of psychosis is due to activation of the hormonal stress response and, specifically, to an increase in the size and number of corticotroph cells producing ACTH, while the increased pituitary volume induced by antipsychotics is linked to the stimulating effects of these drugs on lactotroph cells producing prolactin. Future studies should address these issues that are relevant in improving the care of patients with psychosis.

Hippocampus volume loss due to chronic heavy drinking

OBJECTIVE

No clear consensus exists regarding the effect of sustained, heavy drinking on hippocampal volume. Our prior work hypothesized significantly lowered total hippocampus volumes in heavy chronically drinking alcohol-dependent (AD) subjects compared with light-drinking nondependent control subjects matched for age and gender.

METHOD

Using a series of applicable exclusion criteria culled from previous published studies, we measured hippocampal volumes from MRI scan data acquired on a 3T scanner and subjected those data to automated volume analysis blind to the drinking history.

RESULTS

Comparison with AD test (n=8) and non-AD control (n=8) subjects found significant lessening in total (p=0.020) and left (p=0.010) hippocampal volumes with a near-significant difference on the right (p=0.051). Linear regression demonstrated that neither total brain volume nor intracranial volume affected the hippocampus measures.

CONCLUSIONS

These data support the view that heavy drinking exerts a unique and selectively injurious effect on the hippocampus. Further study in larger samples must verify this in a search for possible mechanisms of injury.

Pituitary volume in treatment-naïve pediatric major depressive disorder

BACKGROUND

Prior pilot investigation identified a larger pituitary gland volume (PGV) in pediatric patients with major depressive disorder (MDD) compared with healthy pediatric control subjects that was most prominent in boys with MDD. In this independent sample, we focus on gender differences in pituitary volume in a larger sample of pediatric patients with MDD.

METHODS

Volumetric magnetic resonance imaging studies were conducted in 35 psychotropic drug-naïve children (15 boys, 20 girls), ages 8-17 years, and 35 case-matched healthy control subjects.

RESULTS

The MDD boys had larger PGV (19%) compared with male control subjects. No significant diagnostic group differences in pituitary volume were observed in girls. Healthy boys had significantly smaller PGV (27%) than healthy girls, whereas MDD boys did not differ from girls with MDD. Nonfamilial (without a family history of mood disorder) boys with MDD had significantly larger PGV (35%) than male healthy control subjects and tended to have a larger PGV (27%) than familial (at least one first-degree relative with MDD) boys with MDD. Boys with familial MDD did not differ from control subjects.

CONCLUSIONS

These findings provide new evidence of increased pituitary volume in psychotropic-naïve pediatric patients with MDD that seems to be more prominent in male patients with nonfamilial MDD.

Pituitary volume in pediatric obsessive-compulsive disorder

BACKGROUND

Abnormalities in the limbic-hypothalamic-pituitary-adrenal (LHPA) axis have been implicated in the pathogenesis of obsessive-compulsive disorder (OCD). To our knowledge, however, no prior study has measured pituitary gland volume in OCD.

METHODS

Volumetric magnetic resonance imaging studies were conducted in 31 psychotropic drug-naïve children (10 boys, 21 girls) aged 8-17 years and 31 case-matched healthy comparison subjects.

RESULTS

Pituitary volume was significantly smaller in patients with OCD as compared with healthy control subjects (11% smaller). Smaller pituitary volume in patients with OCD was associated with increased compulsive but not obsessive symptom severity. Boys with OCD had smaller pituitary gland volumes compared with control boys (20% smaller). No significant differences in pituitary volume were observed between girls with OCD and control girls. Boys with OCD had significantly smaller pituitary volumes than girls with OCD (31% smaller), whereas control boys also had smaller pituitary gland volumes compared with control girls (21% smaller).

CONCLUSIONS

These findings provide new evidence of reduced pituitary volume in pediatric OCD that seems to be more prominent in male patients. The observed alterations in pituitary volume are consistent with neuroendocrine studies that have reported abnormalities in the LHPA axis in OCD.

MR-based in vivo hippocampal volumetrics: 2. Findings in neuropsychiatric disorders

Magnetic resonance imaging (MRI) has opened a new window to the brain. Measuring hippocampal volume with MRI has provided important information about several neuropsychiatric disorders. We reviewed the literature and selected all English-language, human subject, data-driven papers on hippocampal volumetry, yielding a database of 423 records. Smaller hippocampal volumes have been reported in epilepsy, Alzheimer's disease, dementia, mild cognitive impairment, the aged, traumatic brain injury, cardiac arrest, Parkinson's disease, Huntington's disease, Cushing's disease, herpes simplex encephalitis, Turner's syndrome, Down's syndrome, survivors of low birth weight, schizophrenia, major depression, posttraumatic stress disorder, chronic alcoholism, borderline personality disorder, obsessive-compulsive disorder, and antisocial personality disorder. Significantly larger hippocampal volumes have been correlated with autism and children with fragile X syndrome. Preservation of hippocampal volume has been reported in congenital hyperplasia, children with fetal alcohol syndrome, anorexia nervosa, attention-deficit and hyperactivity disorder, bipolar disorder, and panic disorder. Possible mechanisms of hippocampal volume loss in neuropsychiatric disorders are discussed.

Alcoholism and neuro-immune-endocrine interactions: physiochemical aspects

The role of alcohol consumption and alcoholism as an addiction in regulating the chemistry of the brain and its physiology has gained a backlog of interest over the past few decades. Besides the notion that alcohol acts as a brain depressant, the molecular mechanisms and neuronal interactions are not well understood. Emerging evidence implicates alcohol as a neurochemical messenger that influences a cross talk amongst the nervous, immune, and endocrine systems. Specifically, alcohol acts as a crucial regulator of the hypothalamic-pituitary-adrenal (HPA) axis, thereby modulating the release of hormones, particularly adrenocorticotropic hormone (ACTH) and corticosterone (CORT). It is the aim of this review, therefore, to investigate current concepts on how alcohol, particularly ethanol, and alcoholism affect neuro-immune-endocrine neurochemical interactions via the regulation of the HPA axis, taking into consideration bio-behavioral and physiochemical aspects.

MRI study of the pituitary gland in adolescent depression

Abnormalities in pituitary function have been described in major depressive disorder (MDD) and may reflect neurodevelopmental abnormalities. We hypothesized alterations in the pituitary in early onset MDD. We measured the volume of the pituitary gland in 17 MDD (mean+/-S.D.=16.67+/-1.83 years; 8M, 9F) patients and 17 age and sex matched healthy controls (mean+/-S.D.=16.23+/-1.61 years; 8M, 9F) using 1.45 mm thick T(1)-weighted coronal MRI images. A trained rater blind to diagnosis did all measurements. ANCOVA covarying for age, sex and intracranial volume (ICV) revealed a significant difference between the two groups (F=6.43, df=1, 29, P=0.02; MDD subjects demonstrated a 25% increase in pituitary gland volume). Age was significantly correlated with pituitary volume in the healthy controls (r=0.62, P=0.008) but not the MDD group. No significant relationships between pituitary size and clinical severity were found in the MDD patients. To our knowledge, this is the first study that reports larger pituitary volumes in early onset major depression. These findings provide new evidence of abnormalities of the pituitary in early onset MDD, possibly related to neuroendocrine dysfunction.

Alcohol abuse and traumatic brain injury: quantitative magnetic resonance imaging and neuropsychological outcome

Prior or concurrent alcohol use at the time of traumatic brain injury (TBI) was examined in terms of post-injury atrophic changes measured by quantitative analysis of magnetic resonance imaging (MRI) and neuropsychological outcome. Two groups of TBI subjects were examined: those with a clinically significant blood alcohol level (BAL) present at the time of injury (TBI + BAL) and those without a significant BAL (TBI-only). To explore the potential impact of both acute and chronic alcohol use, subjects in both groups were further clustered into one of four subgroups (NONE, MILD, MODERATE or HEAVY) based upon available information regarding their pre-injury alcohol use. One-way analysis of covariance (ANCOVA) and multiple analysis of covariance (MANCOVA) were used with subject grouping as the main factor. Age, injury severity as measured by Glasgow Coma Scale (GCS) score, years of education, total intracranial volume (TICV), and the number of days post-injury were included as covariates where appropriate. Increased general atrophy was observed in patients with (a) a positive BAL and/or (b) a history of moderate to heavy pre-injury alcohol use. In addition, performance on neuropsychological outcome variables (WAIS-R and WMS-R Index scores) was generally worse in the subgroups of patients with positive BAL and a history of preinjury alcohol use, as compared to the other TBI groups though not statistically significant. Implications of alcohol use, at the time of brain injury, are discussed.

Reduced Hippocampal Volume in Alcohol and Substance Naïve Vietnam Combat Veterans with Posttraumatic Stress Disorder

OBJECTIVE

This pilot study was undertaken to exclude the effects of alcohol and other substances on brain morphology in posttraumatic stress disorder.

BACKGROUND

Posttraumatic stress disorder and alcohol use are among the conditions associated with decreased hippocampal volume. The possible confounding contribution of alcohol and other substances of abuse to decreased hippocampal volume in posttraumatic stress disorder has not been previously explored directly.

METHOD

In this pilot study, magnetic resonance imaging scans of 4 substance naive subjects with combat-related posttraumatic stress disorder and of 4 controls were quantified.

RESULTS

Bilateral hippocampal volumes were significantly smaller in posttraumatic stress disorder subjects. No significant differences were found between posttraumatic stress disorder subjects and the comparison group for total brain, gray and white matter, and ventricular volumes.

CONCLUSIONS

These findings suggest that posttraumatic stress disorder in the absence of alcohol and other substance abuse may be associated with reduced hippocampal volume. The significance of reduced hippocampal volume in posttraumatic stress disorder is discussed.

Open-label nefazodone in patients with a major depressive episode and alcohol dependence

PURPOSE

Major depressive disorder (MDD) and alcohol dependence (AD) frequently occur together. However, MDD clinical trials generally exclude patients with alcohol-related disorders.

GENERAL METHODS

A 12-week, open-label trial of nefazodone in a group of people (n=13) with both a current major depressive episode and current AD was conducted to examine the effect of this antidepressant on depressive symptoms, alcohol use, and cognition.

FINDINGS

Scores on the Hamilton Rating Scale for Depression (HRSD) and Hamilton Rating Scale for Anxiety (HRSA) significantly decreased from baseline to exit. In addition, significant reduction in alcohol craving, drinks/week, and days of alcohol use/week was found. Scores on the Rey Auditory Verbal Learning Test (RAVLT) did not significantly improve during the study. Changes in mood/anxiety and memory did not correlate with changes in alcohol use.

CONCLUSIONS

Thus, nefazodone therapy was associated with improvement in mood/anxiety and alcohol use, which seem to be independent of each other in this patient sample. However, declarative memory, which was low average at baseline, did not show statistically significant improvement during the 12 weeks of the study.

Induction of nicotine-metabolizing CYP2B1 by ethanol and ethanol-metabolizing CYP2E1 by nicotine: summary and implications

Alcohol and tobacco are frequently co-abused. Increased alcohol use and alcoholism are associated with smoking, and vice versa. Functional and/or metabolic cross-tolerance may contribute to this occurrence. This review summarizes recent studies published from our laboratory focusing on metabolic aspects of tolerance, which demonstrate that in rat, subchronic, behaviourally relevant doses of ethanol induce hepatic nicotine-metabolizing cytochrome P450 (CYP) 2B1, and that subchronically administered nicotine, at behaviourally relevant doses, induces hepatic ethanol-metabolizing CYP2E1. Increased CYP2B1 protein, mRNA and CYP2B1-mediated nicotine metabolism was observed following ethanol treatments. CYP2E1 protein and activity were induced by nicotine, but no changes were seen in levels of CYP2E1 mRNA. These data indicate that metabolic cross-tolerance may occur between nicotine and ethanol, suggesting that nicotine use may increase the elimination of ethanol, and ethanol use may increase the elimination of nicotine. Other implications, such as altered pharmacology and toxicology of drugs metabolized by these enzymes, as well as changes in pro-carcinogen and pro-toxin activation are also discussed.

Induction of CYP2B1/2 and nicotine metabolism by ethanol in rat liver but not rat brain

A higher proportion of alcoholics than non-alcoholics smoke (>80 vs 30%). In animals, chronic administration of alcohol induces tolerance to some effects of nicotine. To investigate if chronic ethanol (EtOH) induces alterations in CYP2B1/2 and nicotine C-oxidation activity, male rats (N = 4-6/group) were treated once daily with saline or EtOH (0.3, 1.0, and 3.0 g/kg, p.o./by gavage) for 7 days. A quantitative immunoblotting assay was developed to detect CYP2B1/2 in the brain, where constitutive expression is low, and in the liver. Using this method, it was determined that EtOH did not alter CYP2B1/2 protein expression significantly in six brain regions (olfactory bulbs, olfactory tubercles, frontal cortex, hippocampus, cerebellum, and brainstem). However, a dose-dependent induction of CYP2B1/2 protein expression was detected in the liver. Significant induction of 2-, 3-, and 2.7-fold were observed for the 0.3, 1.0, and 3.0 g/kg doses, respectively. Increases were also observed in CYP2B1 mRNA, which was induced by 14, 38, and 43% at the same doses. Liver microsomal nicotine C-oxidation also was increased (1.3 to 4.5-fold). CYP2B selective inactivators demonstrated that approximately 70% of nicotine C-oxidation was mediated by CYP2B1/2 in both EtOH-induced and uninduced hepatic microsomes. In summary, chronic, behaviorally relevant doses of EtOH induce CYP2B1/2 protein, mRNA, and nicotine C-oxidation activity in rat liver but not in rat brain, and these increases could contribute to cross-tolerance and co-abuse of ethanol and nicotine.

Decreased pituitary volume in patients with bipolar disorder

BACKGROUND

Neuroendocrinologic investigations in bipolar disorder have suggested abnormalities in pituitary function. However, few imaging studies have evaluated possible anatomical differences in this brain structure in mood disorder patients. Our aim was to examine potential abnormalities in pituitary volume in patients with bipolar and in a comparison group of patients with unipolar disorder.

METHODS

We measured the volumes of the pituitary gland in 23 patients with bipolar disorder (mean +/- s.d. = 34.3 +/- 9.9 years) and 13 patients with unipolar disorder (41.2 +/- 9.6 years), and 34 healthy control subjects (36.6 +/- 9.6 years) using 1.5 mm thick T1-weighted coronal 1.5 T MRI images. All measurements were done blindly by a trained rater.

RESULTS

Patients with bipolar disorder had significantly smaller pituitary volumes than healthy control subjects (mean volume +/- s.d. = 0.55 +/- 0.15 ml and 0.68 +/- 0.20 ml, respectively; ANCOVA, F = 8.66, p = 0.005), and than patients with unipolar disorder (0.70 +/- 0.12 ml, F = 5.98, p = 0.02). No differences were found between patients with unipolar disorder and healthy control subjects (F = 0.01, p = 0.91).

CONCLUSIONS

To our knowledge, this is the first study that reports smaller pituitary volumes in bipolar disorder. Our findings suggest that detectable abnormalities in pituitary size are present in patients with bipolar disorder, which may reflect a dysfunctional HPA axis.