The interplay of chronic stress and genetic traits discriminates between patients suffering from multisomatoform disorder with pain as the leading symptom and matched controls

OBJECTIVE

Somatoform disorders and functional somatic syndromes (FSS) with symptoms that are not sufficiently explained by physical or technical examination are among the most challenging underlying causes. Many different somatoform disorders and FSS have overlapping symptoms, often with pain as the most prevalent one, leading to a high burden of disease. The concept of multisomatoform disorder (MSD) has been developed to acknowledge that fact. We analyzed a group of 151 patients and 149 matched controls to identify interactions of genetic and environmental factors with a possible influence on the development of MSD.

DESIGN

In a retrospective case-control study, we performed a statistical analysis on 151 patients and 149 matched controls using logistic regression and a Classification and Regression Tree (CART) analysis.

RESULTS

The logistic regression analysis of genes and environmental factors demonstrated significant differences in the results of the Trier Inventory of Chronic Stress (TICS) questionnaire, the single nucleotide polymorphism rs1800955 of the dopamine receptor D4 and the single nucleotide polymorphism rs4818 of the enzyme catechol-O-methyltransferase between patients with MSD and healthy controls. The resulting decision tree of the CART analysis determined that the TICS questionnaire was able to differentiate patients and controls most accurately, followed by certain genotypes of the 5-hydroxytryptamine receptor 2A and a single nucleotide polymorphism of the enzyme catechol-O-methyltransferase.

CONCLUSIONS

The results of the statistical analysis identified a gene-environmental interaction possibly leading to MSD. The resulting identifiers could be used as a reference to inform diagnostic algorithms to easier identify patients suffering from MSD.

"Not Just Right Experiences" as a psychological endophenotype for obsessive-compulsive disorder: Evidence from an Italian family study

The heart of the obsessional process may be considered the subject's underlying impression that "something is wrong" or "that something is not just as it should be". This phenomenon, labeled "not just right experiences" (NJREs), has increasingly been receiving attention as a possible marker of obsessive-compulsive disorder (OCD). The present study sought to add to the evidence that NJREs may be a putative endophenotype of obsessional symptoms. To this aim, measures of NJREs, obsessive-compulsive (OC) symptoms and psychological distress were compared in offspring of parents with and without OC symptoms. The offspring of parents with OC symptoms (N=120) reported higher frequency and severity of NJREs compared to offspring of parents without OC symptoms (N=106). Such differences remained significant for NJREs frequency and close to significance for NJREs severity, when general distress (i.e., anxiety and depression) was controlled. The possible role of NJREs as an endophenotype for OCD is discussed in reference to Gottesman and Gould criteria and the National Institute of Mental Health RDoC initiative.

Somatic, positive and negative domains of the Center for Epidemiological Studies Depression (CES-D) scale: a meta-analysis of genome-wide association studies

BACKGROUND

Major depressive disorder (MDD) is moderately heritable, however genome-wide association studies (GWAS) for MDD, as well as for related continuous outcomes, have not shown consistent results. Attempts to elucidate the genetic basis of MDD may be hindered by heterogeneity in diagnosis. The Center for Epidemiological Studies Depression (CES-D) scale provides a widely used tool for measuring depressive symptoms clustered in four different domains which can be combined together into a total score but also can be analysed as separate symptom domains.

METHOD

We performed a meta-analysis of GWAS of the CES-D symptom clusters. We recruited 12 cohorts with the 20- or 10-item CES-D scale (32 528 persons).

RESULTS

One single nucleotide polymorphism (SNP), rs713224, located near the brain-expressed melatonin receptor (MTNR1A) gene, was associated with the somatic complaints domain of depression symptoms, with borderline genome-wide significance (p discovery = 3.82 × 10-8). The SNP was analysed in an additional five cohorts comprising the replication sample (6813 persons). However, the association was not consistent among the replication sample (p discovery+replication = 1.10 × 10-6) with evidence of heterogeneity.

CONCLUSIONS

Despite the effort to harmonize the phenotypes across cohorts and participants, our study is still underpowered to detect consistent association for depression, even by means of symptom classification. On the contrary, the SNP-based heritability and co-heritability estimation results suggest that a very minor part of the variation could be captured by GWAS, explaining the reason of sparse findings.

Variants within the GABA transaminase (ABAT) gene region are associated with somatosensory evoked EEG potentials in families at high risk for affective disorders

BACKGROUND

Depression frequently co-occurs with somatization, and somatic complaints have been reported as a vulnerability marker for affective disorders observable before disease onset. Somatization is thought to result from an increased attention to somatic sensations, which should be reflected in long-latency somatosensory evoked electroencephalogram (EEG) potentials (SSEPs) at the physiological level. Previous studies revealed that SSEPs are altered in depressed patients and suggested late SSEP components as vulnerability markers for affective disorders. Neurotransmitters such as serotonin, γ-aminobutyric acid (GABA) and the neuropeptide substance P may play an important role for both affective disorders and somatosensory processing. Method We investigated the associations between SSEPs and polymorphisms within candidate genes of the serotonergic, GABAergic as well as the substance P system in subjects at high risk for affective disorders. The sample was composed of high-risk families participating in the Munich Vulnerability Study and genetic association analyses were calculated using qfam (family-based association tests for quantitative traits) implemented in PLINK 1.05.

RESULTS

We observed significant associations (false discovery rate <0.05) withstanding correction for multiple testing between late SSEP components (response strength 170-370 ms after stimulation) and four single nucleotide polymorphisms within the GABA transaminase (ABAT) gene region coding for a protein responsible for GABA degradation. No effects were found with the classical disease trait approach, suggesting SSEP marker specificity of the observed associations.

CONCLUSIONS

Our findings point to a possible role of ABAT gene-regulated GABA catabolism for an altered processing of somatosensory stimuli as a potential vulnerability marker for affective disorders.

Genetic co-morbidity between neuroticism, anxiety/depression and somatic distress in a population sample of adolescent and young adult twins

BACKGROUND

Genetic studies in adults indicate that genes influencing the personality trait of neuroticism account for substantial genetic variance in anxiety and depression and in somatic health. Here, we examine for the first time the factors underlying the relationship between neuroticism and anxiety/depressive and somatic symptoms during adolescence.

METHOD

The Somatic and Psychological Health Report (SPHERE) assessed symptoms of anxiety/depression (PSYCH-14) and somatic distress (SOMA-10) in 2459 adolescent and young adult twins [1168 complete pairs (35.4% monozygotic, 53% female)] aged 12-25 years (mean=15.5 ± 2.9). Differences between boys and girls across adolescence were explored for neuroticism, SPHERE-34, and the subscales PSYCH-14 and SOMA-10. Trivariate analyses partitioned sources of covariance in neuroticism, PSYCH-14 and SOMA-10.

RESULTS

Girls scored higher than boys on both neuroticism and SPHERE, with SPHERE scores for girls increasing slightly over time, whereas scores for boys decreased or were unchanged. Neuroticism and SPHERE scores were strongly influenced by genetic factors [heritability (h(2)) = 40-52%]. A common genetic source influenced neuroticism, PSYCH-14 and SOMA-10 (impacting PSYCH-14 more than SOMA-10). A further genetic source, independent of neuroticism, accounted for covariation specific to PSYCH-14 and SOMA-10. Environmental influences were largely specific to each measure.

CONCLUSIONS

In adolescence, genetic risk factors indexed by neuroticism contribute substantially to anxiety/depression and, to a lesser extent, perceived somatic health. Additional genetic covariation between anxiety/depressive and somatic symptoms, independent of neuroticism, had greatest influence on somatic distress, where it was equal in influence to the factor shared with neuroticism.

Intra- and interfamily phenotypic diversity in pain syndromes associated with a gain-of-function variant of NaV1.7

BACKGROUND

Sodium channel NaV1.7 is preferentially expressed within dorsal root ganglia (DRG), trigeminal ganglia and sympathetic ganglion neurons and their fine-diamter axons, where it acts as a threshold channel, amplifying stimuli such as generator potentials in nociceptors. Gain-of-function mutations and variants (single amino acid substitutions) of NaV1.7 have been linked to three pain syndromes: Inherited Erythromelalgia (IEM), Paroxysmal Extreme Pain Disorder (PEPD), and Small Fiber Neuropathy (SFN). IEM is characterized clinically by burning pain and redness that is usually focused on the distal extremities, precipitated by mild warmth and relieved by cooling, and is caused by mutations that hyperpolarize activation, slow deactivation, and enhance the channel ramp response. PEPD is characterized by perirectal, periocular or perimandibular pain, often triggered by defecation or lower body stimulation, and is caused by mutations that severely impair fast-inactivation. SFN presents a clinical picture dominated by neuropathic pain and autonomic symptoms; gain-of-function variants have been reported to be present in approximately 30% of patients with biopsy-confirmed idiopathic SFN, and functional testing has shown altered fast-inactivation, slow-inactivation or resurgent current. In this paper we describe three patients who house the NaV1.7/I228M variant.

METHODS

We have used clinical assessment of patients, quantitative sensory testing and skin biopsy to study these patients, including two siblings in one family, in whom genomic screening demonstrated the I228M NaV1.7 variant. Electrophysiology (voltage-clamp and current-clamp) was used to test functional effects of the variant channel.

RESULTS

We report three different clinical presentations of the I228M NaV1.7 variant: presentation with severe facial pain, presentation with distal (feet, hands) pain, and presentation with scalp discomfort in three patients housing this NaV1.7 variant, two of which are from a single family. We also demonstrate that the NaV1.7/I228M variant impairs slow-inactivation, and produces hyperexcitability in both trigeminal ganglion and DRG neurons.

CONCLUSION

Our results demonstrate intra- and interfamily phenotypic diversity in pain syndromes produced by a gain-of-function variant of NaV1.7.

Serotonin-related gene pathways associated with undifferentiated somatoform disorder

It has been suggested that serotonergic hypofunction and serotonergic pathway genes underlie the somatic symptoms of somatoform disorders. We examined a variety of serotonin-related gene polymorphisms to determine whether undifferentiated somatoform disorder is associated with specific serotonin-related gene pathways. Serotonin-related polymorphic markers were assessed using single nucleotide polymorphism (SNP) genotyping. One hundred and two patients with undifferentiated somatoform disorder and 133 healthy subjects were enrolled. The genotype and allele frequencies of tryptophan hydroxylase (TPH)1 A218C, TPH2 rs1386494, serotonin receptor 2A-T102C (5-HTR 2A-T102C), 5-HTR 2A-G1438A and serotonin transporter (5HTTLPR) gene were compared between the groups. The Hamilton Rating Scale for Depression and the somatization subscale of the Symptom Checklist-90-Revised (SCL-90-R) were used for psychological assessment. Patients with undifferentiated somatoform disorder had higher frequencies of the TPH1 C allele than healthy controls (p=0.02) but the difference was not significant after Bonferroni correction. The frequency of TPH1 genotype also did not differ significantly between the patients and the healthy controls, nor did TPH2 rs1386494, 5-HTR 2A-T102C, 5-HTR 2A-G1438A or 5HTTLPR allele and genotype frequencies differ significantly between the two groups. These findings suggest that a variety of serotonin-related gene pathways are unlikely to be definite genetic risk factors for undifferentiated somatoform disorder. Therefore, the pathogenesis of the disorder may be related to epigenetic factors, including psychosocial and cultural factors. Nonetheless, future studies need to include a larger sample of subjects and polymorphisms of more serotonin-related gene variants.

Psycho-social and clinical variables associated with depression in patients with type 2 diabetes

BACKGROUND

Type 2 diabetes (T2DM) doubles the odds of comorbid depression. Depression is a strong predictor of developing T2DM. The aim of the study was to compare depressed patients with T2DM to non-depressed ones with respect to demographic, psycho-social, clinical, anthropometric and metabolic characteristics; to examine the relationship between glycemic control and depression severity in depressed patients; to estimate the risk factors of depression.

SUBJECTS AND METHODS

A group of depressed diabetic patients comprising those with a Major depressive episode, first or repeated (ICD-10; 1992) and endocrinologist-diagnosed T2DM, duration ≥5 years on oral, insulin therapy or both (N=46) and non-depressed ones (N=44) (90 in total) of both genders (<65 years) were included in this cross-sectional study. Laboratory and non-laboratory measures were performed.. The patient Health Questionnaire (PHQ-9) and a structured interview (MINI) were used to establish diagnosis, while the Beck Depression Inventory (BDI; cut off ≥16) was used to assess the severity ofdepression. Scaling of Life Events (SLE) for self-assessment of life events and Problem in Areas in Diabetes (PAID) for self-assessment of diabetes distress were also performed.

RESULTS

Statistically significant higher rates of psychiatric heredity, neuropathy, higher level of diabetes related distress and a greater number of life events in depressed patients compared to non-depressed ones were found. There was a statistically significant positive correlation between BDI somatic subscore and the HbA1c level (r=0.343; p=0.020). The level of diabetes related distress (OR=1.084; p=0.000), total number of life events (OR=4.528; p=0.001) and neuropathy (OR=8.699; p=0.039) were statistically significant predictors of depression using logistic regression.

CONCLUSIONS

The results obtained showed that depression in diabetic patients was predicted by both psychological (diabetes related distress, life events) and disease-specific variables (neuropathy). The severity of self-reported somatic depressive symptoms significantly correlated with the HbA1c level in depressed diabetic patients.

Somatization, but not depression, is characterized by disorders in the tryptophan catabolite (TRYCAT) pathway, indicating increased indoleamine 2,3-dioxygenase and lowered kynurenine aminotransferase activity

BACKGROUND

Reduced plasma tryptophan occurs in depression and somatization. Induction of indoleamine 2,3-dioxygenase (IDO) with consequent synthesis of tryptophan catabolites (TRYCATs) and lowered tryptophan are associated with the onset of depression in the puerperium and during interferon-alpha treatment. Depression is accompanied by lowered kynurenic acid, a neuroprotectant, or increased kynurenine, a neurotoxic TRYCAT.

AIMS AND METHODS

To examine plasma tryptophan; kynurenine; kynurenic acid; the kynurenine / tryptophan (KY/TRP) ratio, indicating IDO activity; and the kynurenine / kynurenic acid (KY/KA) ratio, indicating kynurenine aminotransferase (KAT) activity, in somatization; depression; somatization + depression; and controls. Illness severity is measured by the Somatic Symptom Index (SSI), the Screening for Somatoform Symptoms (SOMS), and the Beck Depression Inventory (BDI).

RESULTS

Tryptophan is significantly lower in patients than in controls and lower in somatization than in depression. KY/TRP is significantly increased in somatization. Kynurenic acid is significantly lower in patients than in controls, and lower in somatization than in depression. KY/KA is significantly higher in somatization and somatization + depression than in depression and controls. There are significant correlations between the severity of somatization, but not depression, and KY/TRP and KY/KA (positive) and tryptophan (negative). Kynurenine and kynurenic acid are significantly correlated in controls, somatization + depression, and depression, but not in somatization.

CONCLUSIONS

Somatization is characterized by increased IDO activity and disorders in KAT activity and an increased neurotoxic potential. The TRYCAT pathway may play a role in the pathophysiology of somatizing and "psychosomatic" symptoms through effects on pain, gut motility, the autonomic nervous system, peripheral NMDA receptors, etc. Even more, biological disorders, such as aberrations in the TRYCAT pathway, which are considered to be a hallmark for depression, are in fact attributable to somatization rather than to depression per se. Future research in depression on the TRYCAT pathway should always control for the possible effects of somatization.

[Emotional, physical and psychiatric disorders in relatives of schizophrenia patients in Mexico]

BACKGROUND

A study was to investigate the frequency with which they have emotional disorders, physical and psychiatric symptoms in FCPI, knowing the relationship with demographic variables and clinical caregivers of patients with schizophrenia.

METHODS

It was a cross sectional, descriptive, correlational, study and ex-post-facto, of a non probabilistic sample, using 131 relatives carers. Instruments. 1-The Compositive International Diagnostic Interview version 1.0 (CIDI) 2-Social Behaviour Assessment Schedule 2nd Ed. (SBAS).

RESULTS

58% of the relatives presented 1 to 4 psychiatric diagnoses, the most frequent was: depression (20.6%), alcohol dependence (9.9%) and dissociative disorders (7.6%); the relatives' carers reported some physical (48%) or emotional (74%) illness related to the presence of the schizophrenia in their relatives.

CONCLUSIONS

The predictive variables associated with the presence of psychopathology in the relatives carers': the presence of active symptomatology in the patient, the years of evolution of the illness and the number of hospitalizations, r = 0.38; p > 0.000.

The Croatian version of diagnostic interview for genetic studies

Diagnostic Interview for Genetic Studies (DIGS) is a modern structured interview schedule that has been in use since 1994. Main purpose of the DIGS is to record information regarding to a subject's functioning and psychopathology and it was specifically designed for psychiatric genetic studies. The DIGS is also suitable for making diagnosis, evaluation of comorbidity and other researches. It contents items and sections and has a semi-structured design that gives interviewers the freedom needed to extract the best in formation possible. The validity of a Croatian version of the DIGS was investigated. The original English version was initially translated into Croatian. The Croatian version was then back-translated and compared with the original. In this paper we will describe each item that DIGS contents as well as the use of this diagnostic instrument.

Psychobiological differences between depression and somatization

BACKGROUND

Comorbidity studies have shown that depression and somatization (multiple somatoform symptoms) often overlap. Therefore it has been suggested to classify at least some patients with somatization syndromes under the category of depressive disorders. We wanted to investigate whether psychobiological investigations confirm the lumping of somatization and depression, or whether psychobiological pathways favor distinguishing these disorders.

METHOD

An overview is presented summarizing psychobiological studies including patients with depression and/or somatization-associated syndromes. We focus on the following topics: heritability, polymorphisms in special candidate genes, immune activation, hypothalamic-pituitary-adrenal (HPA) axis reactivity, serotonergic pathways, monoamino acids, and fatty acid concentrations.

RESULTS

Immunological activation seems to be associated with specific features of somatoform disorders, namely, sickness behavior and pain thresholds. Genetic factors can also contribute to somatic complaints, e.g., via serotonergic pathways, HPA-axis response, immune activation, and other biological systems that contribute to the self-description of not being healthy. Some results indicate that psychobiological aspects of depression and somatization overlap in part (e.g., the relevance of serotonergic pathways), but there is clearly more evidence for discrepancies of psychobiological pathways in depression and somatization (e.g., the relevance of proinflammatory immune processes; HPA-axis activity; monoamino acid availability; omega-3-concentration; the role of triallelic subtypes of 5-HTTLPR).

CONCLUSION

Many psychobiological pathways act differently in depression and somatization. These differences in psychobiology favor the distinction of these syndromes in classification approaches.

Emotional disorders: cluster 4 of the proposed meta-structure for DSM-V and ICD-11

BACKGROUND

The extant major psychiatric classifications DSM-IV, and ICD-10, are atheoretical and largely descriptive. Although this achieves good reliability, the validity of a medical diagnosis would be greatly enhanced by an understanding of risk factors and clinical manifestations. In an effort to group mental disorders on the basis of aetiology, five clusters have been proposed. This paper considers the validity of the fourth cluster, emotional disorders, within that proposal.

METHOD

We reviewed the literature in relation to 11 validating criteria proposed by a Study Group of the DSM-V Task Force, as applied to the cluster of emotional disorders.

RESULTS

An emotional cluster of disorders identified using the 11 validators is feasible. Negative affectivity is the defining feature of the emotional cluster. Although there are differences between disorders in the remaining validating criteria, there are similarities that support the feasibility of an emotional cluster. Strong intra-cluster co-morbidity may reflect the action of common risk factors and also shared higher-order symptom dimensions in these emotional disorders.

CONCLUSION

Emotional disorders meet many of the salient criteria proposed by the Study Group of the DSM-V Task Force to suggest a classification cluster.

A population-based twin study of functional somatic syndromes

BACKGROUND

The mechanisms underlying the co-occurrence of the functional somatic syndromes are largely unknown. No empirical study has explicitly examined how genetic and environmental factors influence the co-morbidity of these syndromes. We aimed to examine how the co-morbidity of functional somatic syndromes is influenced by genetic and environmental factors that are in common to the syndromes.

METHOD

A total of 31318 twins in the Swedish Twin Registry aged 41-64 years underwent screening interviews via a computer-assisted telephone system from 1998 to 2002. Four functional somatic syndromes (chronic widespread pain, chronic fatigue, irritable bowel syndrome, and recurrent headache) and two psychiatric disorders (major depression and generalized anxiety disorder) were assessed using structured questions based on standard criteria for each illness in a blinded manner.

RESULTS

Multivariate twin analyses revealed that a common pathway model with two latent traits that were shared by the six illnesses fit best to the women's data. One of the two latent traits loaded heavily on the psychiatric disorders, whereas the other trait loaded on all four of the functional somatic syndromes, particularly chronic widespread pain, but not on the psychiatric disorders. All illnesses except the psychiatric disorders were also affected by genetic influences that were specific to each.

CONCLUSIONS

The co-occurrence of functional somatic syndromes in women can be best explained by affective and sensory components in common to all these syndromes, as well as by unique influences specific to each of them. The findings clearly suggest a complex view of the multifactorial pathogenesis of these illnesses.

Preliminary evidence of association between EFHC2, a gene implicated in fear recognition, and harm avoidance

Genetic variation at the EF-hand domain containing 2 gene (EFHC2) locus has been associated with fear recognition in Turner syndrome. The aim of this study was to examine whether EFHC2 variants are associated with non-syndromic anxiety-related traits [harm avoidance (HA) and behavioral inhibition (BI)] and with panic disorder (PD). Our sample comprised 127 PD patients and 132 controls without psychiatric disorder. We genotyped nine SNPs within the EFHC2 locus and used PLINK to perform association analyses. An intronic SNP (rs1562875) was associated with HA (permuted p=0.031) accounting alone for over 3% of variance in this trait. This same SNP was nominally, but not empirically, associated with BI (r(2)=0.022; nominal p=0.022) and PD (OR=2.64; nominal p=0.009). The same association was found in a subsample of only females. In sum, we observed evidence of association between a variant in EFHC2, a gene previously associated with the processing of fear and social threat, and HA. Larger studies are warranted to confirm this association.

HSV vectors for gene therapy of chronic pain

Chronic pain is a serious debilitating condition affecting a large number of individuals and with substantial societal impact in terms of quality-of-life and absence from work. Current therapies often exhibit activity at sites other than the nervous system and so are limited by 'off-target' adverse effects. These adverse effects often prevent the administration of an effective therapeutic dose of the approved drug(s). Viral vectors have the potential to deliver and express short-lived, but potent therapeutic peptides in the nervous system. Vector-expressed peptides interrupt or modulate the transmission of nociceptive signals without systemic distribution or off-target effects. This review focuses on the use of non-replicating HSV-based vectors that are introduced into the skin and transduce dorsal root ganglia to express analgesic molecules locally in the spinal cord. Data from preclinical animal models as well as studies that support early phase clinical trials from 2002 to 2008 are described.

The relationship of body dysmorphic disorder and eating disorders to obsessive-compulsive disorder

Body dysmorphic disorder (BDD) and eating disorders are body image disorders that have long been hypothesized to be related to obsessive-compulsive disorder (OCD). Available data suggest that BDD and eating disorders are often comorbid with OCD. Data from a variety of domains suggest that both BDD and eating disorders have many similarities with OCD and seem related to OCD. However, these disorders also differ from OCD in some ways. Additional research is needed on the relationship of BDD and eating disorders to OCD, including studies that directly compare them to OCD in a variety of domains, including phenomenology, family history, neurobiology, and etiology.

Serotonin transporter gene influences the time course of improvement of "core" depressive and somatic anxiety symptoms during treatment with SSRIs for recurrent mood disorders

The short variant of the serotonin transporter gene (SERTPR) has been consistently associated with a poorer response to treatment with various selective serotonin reuptake inhibitors (SSRIs). Antidepressant response is not a unitary phenomenon, however, and we here hypothesized that the SERTPR effect could be specific to some types of symptomatology. The sample comprised 281 inpatients affected by mood disorders and treated for major depression with SSRIs. The total depressive scores for all patients were analyzed in previous reports, but symptomatologic clusters were not examined previously. The 21-item Hamilton Rating Scale for Depression (HAM-D) was administered to evaluate depressive symptoms at baseline and weekly over 6 weeks of treatment. All patients were genotyped for the SERTPR polymorphism. Compared with patients with the SERTPR l/l and l/s polymorphisms, s/s patients showed a selective and slower improvement of depressive "core" and somatic anxiety symptoms, but they did not differ from other patients regarding other symptomatologic clusters such as insomnia and motor retardation. These findings support the view that response to SSRIs is not a unitary phenomenon and that improvement of symptomatologic clusters as, at least in part, genetically driven. SERTPR may be hypothesized as concurrently participating to the activity of anatomic brain regions differentially involved in depression and somatic symptoms of anxiety; however, further studies are required to examine these complex interactions.

Distinguishing between hypochondriasis and somatization disorder: a review of the existing literature

A valid classification is important for further understanding of the somatoform disorders. The main disorders in this grouping - somatization disorder and hypochondriasis - have lengthy historical traditions and are defined in a contrasting manner. Various authors point to distinguishing demographic and clinical features, but there have been few direct comparisons of patients with these disorders. A review of the literature indicates those domains where differences are most likely to be found. Research assessing these may serve to refine and validate these key somatoform categories and/or dimensions.

Does work on obsessive-compulsive spectrum disorders contribute to understanding the heterogeneity of obsessive-compulsive disorder?

BACKGROUND

There is a growing literature on the concept of an obsessive-compulsive spectrum of disorders. Here, we consider the different dimensions on which obsessive-compulsive spectrum (OCSDs) lie, and focus on how the concepts from this literature may help understand the heterogeneity of obsessive-compulsive disorder (OCD).

METHODS

A computerized literature search (MEDLINE: 1964-2005) was used to collect studies addressing different dimensions on which the OCSDs lie. Against this backdrop, we report on a cluster analysis of OCSDs within OCD.

RESULTS

OCSDs may lie on several different dimensions. Our cluster analysis found that in OCD there were 3 clusters of OCD spectrum symptoms: (1) "Reward deficiency" (including trichotillomania, pathological gambling, hypersexual disorder and Tourette's disorder), (2) "Impulsivity" (including compulsive shopping, kleptomania, eating disorders, self-injury and intermittent explosive disorder), and (3) "Somatic" (including body dysmorphic disorder and hypochondriasis).

CONCLUSIONS

It is unlikely that OC symptoms and disorders fall on any single phenomenological dimension; instead, multiple different constructs may be required to map this nosological space. Although there is evidence for the validity of some of the relevant dimensions, additional work is required to delineate more fully the endophenotypes that underlie OC symptoms and disorders.

Association analysis of serotonin transporter promoter gene polymorphism with ADHD and related symptomatology

Attention deficit hyperactivity disorder (ADHD) is one of the most common childhood behavioral disorders. Genetic factors contribute to the underlying liability to develop attention deficit hyperactivity disorder. Several investigations have reported associations between ADHD and serotonin transporter promoter polymorphisms, but the results have been inconsistent. The present study did not find significant association between ADHD and serotonin transporter promoter polymorphisms, but did find an effect of serotonin transporter promoter polymorphisms on some ADHD symptomatology. Patients homozygous for the short allele showed more Withdrawn or Somatic complaint scores than subjects with the long allele.

Intergenerational transmission of somatization behaviour: 2. Observations of joint attention and bids for attention

BACKGROUND

Somatoform disorders may have their roots in childhood through processes that involve an enhanced parental focus on health. The aim of this study was to test the hypothesis that somatizing mothers will show less joint involvement than other mothers during play but greater responsiveness when this play involves a 'medical' theme.

METHOD

Cross-sectional observational study of 42 chronic somatizers, 44 organically ill and 50 healthy mothers and their 4-8 year-old children during structured play and a meal. Tasks comprised boxes containing tea-set items, 'medical' items and a light snack.

RESULTS

Somatizing mothers were emotionally flatter and showed lower rates of joint attention than other mothers during both play tasks. While the three groups had similar rate of bids for attention, somatizing mothers were more responsive to their child's bids during play with the medical box than at other times. In contrast, the children of somatizing mothers ignored a greater proportion of their mother's bids during play with the medical box than did children of other mothers or during play with a non-medical theme.

CONCLUSION

The study has demonstrated tentative evidence in support of the hypothesis.

Familial aggregation of irritable bowel syndrome: a prospective study

BACKGROUND

Patients with irritable bowel syndrome (IBS) often report family members with similar symptoms, but family studies are lacking. We hypothesised that if there is familial aggregation, there would be an increased frequency of IBS in first degree relatives of IBS patients compared with relatives of controls (the patient's spouse).

METHODS

A valid self report bowel disease questionnaire (BDQ) that recorded symptoms, the somatic symptom checklist (a measure of somatisation), and a family information form (FIF) to collect the names and addresses of all first degree relatives were mailed to two groups of patients and their spouses (patients attending an IBS educational programme and residents of Olmsted County, Minnesota, who had been coded as IBS on a database). A BDQ was then mailed to all first degree relatives of subjects identified from the FIF. IBS diagnosis in the relatives was based on the Manning criteria.

RESULTS

The BDQ was sent to a total of 355 eligible relatives; 71% responded (73% relatives of patients, 67% relatives of spouses). Relatives were comparable in mean age, sex distribution, and somatisation score. IBS prevalence was 17% in patients' relatives versus 7% in spouses' relatives (odds ratio adjusted for age and sex 2.7 (95% confidence interval (CI) 1.2, 6.3)). When also adjusted for somatisation score, the odds ratio was reduced to 2.5 (95% CI 0.9, 6.7).

CONCLUSIONS

Familial aggregation of IBS occurs, supporting a genetic or intrafamilial environment component, but this may be explained in part by familial aggregation of somatisation.

Happiness and Health: Environmental and Genetic Contributions to the Relationship Between Subjective Well-Being, Perceived Health, and Somatic Illness

The aim was to identify genetic and environmental influences on the covariances between subjective well-being (SWB), perceived health, and somatic illness. Analyses were based on 6576 Norwegian twins aged 18-31. Heritabilities ranged from .24 to.66. SWB correlated .50 with perceived health, -.25 with musculoskeletal pain, and -.07 with allergy. Common genetic factors accounted for 45%-60% of associations. SWB and perceived health was to a high extent influenced by the same genes (r(g)=.72 and.82 for males and females, respectively). For SWB and musculoskeletal pain, r-sub(g) =-.29 and -.42 for males and females, respectively. Effects were partly sex specific. Environmental factors shared by twins did not affect the covariances. Results support a differentiated view of SWB-health relations, and imply that both genes and environment play important roles in the associations between well-being and health.

Life events and depressiveness - the effect of adjustment for psychosocial factors, somatic health and genetic liability

OBJECTIVE

To study the nature of the relationship of life events with depressiveness.

METHOD

In 1990, 9947 Finnish adult twins aged 33-60 years participated in a questionnaire study, with no missing data on the analysed variables. The relationship between stressful life-events and depressiveness, based on Beck Depression Inventory (BDI) classified as normal, mild or moderate, was analysed using multinomial regression for all subjects with adjustment for the effect of age, sex, health status, social support, marital status, social class, and personality variables. These same factors were analyzed among 643 twin pairs discordant for depressiveness.

RESULTS

High BDI score categories were strongly associated with stressful life events in all individuals and equally strongly within discordant twin pairs, both monozygotic and dizygotic. Poor somatic health and lack of social support also increased depressiveness.

CONCLUSION

The effect of life events predicting depressiveness was independent of social support, somatic disease, sex and genetic liability.

Mass family hysteria: a report from India

The case of a 31-member family displaying mass hysteria in up to 10 members at one time is reported. The mass hysteria emerged in the context of the strong religious and cultural beliefs held by this closely knit family. The varied presentations included somatoform disorder, recurrent vomiting, conversion, dissociative and possession attacks. Two members had bipolar affective disorder that was recognized by the family as a 'medical' illness in contrast to other problems attributed to religiosity. The rarity of mass hysteria in a family and issues related to its medical and social management are highlighted.

[Genetics and somatoform disorders]

The nosological status of somatoform disorders has long been unclear. Only with DSM-III in 1980 did the situation become more settled. This means that earlier theoretical speculation and empirical investigations are difficult to evaluate. It has not been possible to confirm empirically many psychoanalytic notions about environmental causes of somatoform disorders; however, Freud's emphasis on a genetic basis seems to be confirmed. Furthermore, genetic research suggests a certain connection between alcoholism and criminality on the one hand and somatization disorders on the other. This does not mean that manifest alcoholism and criminality is prevalent among people with somatoform disorders. Cultural, gender-specific barriers and environmental factors prevent much co-morbidity. It should, however, be noted that little research has been taking place over the last 25-30 years; we could hardly be said to be beginning to understand the interplay between genes and environment in the development of somatoform disorders.

A descriptive analysis of minor depression

OBJECTIVE

The authors provide a detailed clinical description of minor depression: its symptoms, level of disability, stability, and relationship to patient and family history of major depressive disorder.

METHOD

Rigorous criteria for minor depression, including functional disability, were used to identify 226 individuals for a three-phase treatment study. This report presents data obtained on that study group during the first study phase, a 4-week placebo lead-in period.

RESULTS

One hundred sixty-two subjects (72% of the initial study group) remained in the study for 4 weeks and continued to meet criteria for minor depression. Minor depression in these subjects was primarily characterized by mood and cognitive symptoms, not the classical neurovegetative signs and symptoms of depression. Approximately one-third of the subjects with minor depression had a past history of major depressive disorder, and nearly half had a family history of unipolar depressive disorder; however, neither factor affected the severity or quality of minor depressive symptoms.

CONCLUSIONS

These data suggest that 1) minor depression is not evanescent; 2) minor depression is characterized by mood and cognitive symptoms rather than neurovegetative symptoms; 3) minor depression may occur either independently of a lifetime history of major depressive disorder or as a stage of illness in the course of recurrent unipolar depressive disorder; and 4) depressive disorders should be conceptualized as a continuum of severity.

[Levels and molecular heterogeneity of serotonin transporter protein in platelets of patients with different mental diseases: a comparative analysis with the use of monoclonal and polyclonal antibodies]

Polyclonal (PAb) and monoclonal (MAb) antibodies to CT2-epitope of the C-terminal fragment of serotonin transporter (SERT) protein were used to study the levels and molecular heterogeneity of platelet SERT in healthy donors and patients with affective (AD) and somatoform (SD) disorders, schizoaffective disorder (SAD) and schizophrenia. SERT was found to exist as high molecular wight (HMW) and low molecular weight (LMW) forms separated after electrophoresis. The levels of HMW and LMW forms of SERT were significantly, decreased in mentally ill patients as compared to healthy individuals. Unlike PAb, horse radish peroxidase (HRP)-conjugated MAbs were more sensitive and specific to SERT and could detect the LMW form of SERT as a duplet protein form with MW about 40 and 43 kDa. The MAb to CT2 C-terminal fragment of SERT conjugated with HRP is considered to be a new valuable tool for further investigation of SERT expression, properties, and posttranslation modification in the controls and in patients with different psychopathology.

Possible association of temporomandibular joint pain and dysfunction with a polymorphism in the serotonin transporter gene

The purpose of this study was to evaluate the relationship between temporomandibular joint pain and dysfunction and serotonin transporter (5-HTT) gene polymorphism. Forty-eight patients with temporomandibular joint pain and 111 healthy control subjects were examined. The results for the patients and control subjects were not significantly different (P >.05). The analysis of genotype distribution (homozygous for STin 2.10 genotypes of the variable-number tandem-repeat polymorphism) showed significant differences between the patients and control subjects (P =.003). ST 2.10 allele was more frequent in the patients with temporomandibular joint pain and dysfunction. In the control group, however, STin 2.12/12 genotype was significantly higher (P =.017). In the patients who were homozygous or heterozygous for variable-number tandem-repeat variants of 5-HTT STin 2.12 copies, the average scores of somatization and anger were significantly higher than those who were homozygous for STin 2.10 variant (P <.05). The patients who were homozygous for STin 2.10 genotype were also homozygous for "L" genotype (P =.019). However, this was not the condition in the control subjects. This study does not provide evidence to support the involvement of 5-HTT gene-linked polymorphic region in temporomandibular joint pain and dysfunction. Our findings indicated that only the presence of the homozygous STin 2.10 genotype of variable-number tandem-repeat is likely to play a substantial role in the genetic predisposition to temporomandibular joint pain and dysfunction and that the STin 2.12/12 genotype may have a protective role against temporomandibular joint pain and dysfunction.

Affective illness in children and adolescents: patterns of presentation in relation to pubertal maturation and family history

Affective illness is now recognized as a common problem in all age groups, and the various patterns have been well documented in adults. The objective of this study was to evaluate the patterns of affective illness in children and determine changes with increasing age and family history. One hundred children/adolescents with affective illness (72 boys and 28 girls; age range 2-20 years; mean age 10 years), who were consecutively referred to the Pediatric Behavioral Neurology Program, Children's Medical Center at Dallas, were evaluated for the pattern and course of affective illness symptoms, family history, and pubertal stage. Seven patterns of affective illness were identified. In the 65 prepubertal children (Tanner stage 1), disorders with hypomanic/manic symptomatology were most common (47/65, 72%): mania (2/65, 3%), hypomania (8/65, 12%), cyclothymia (11/65, 17%), juvenile rapid-cycling bipolar disorder/ultradian cycling bipolar disorder (8/65, 12%), and dysthymia with bipolar features (18/65, 28%). In contrast, the 26 fully pubertal adolescents (Tanner stages 3-5) had a predominance of patterns with only depressive symptomatology (16/26, 61%): dysthymia (4/26, 15%) and depression (12/26, 46%), along with juvenile rapid-cycling bipolar disorder/ultradian cycling bipolar disorder (6/26, 23%). Affective illness, alcoholism, and drug abuse were prominent in the family histories, regardless of the child's pattern of symptoms. Family histories of character disorder and Briquet's syndrome were also common, but thought disorder, suicide, and homicide were infrequent. This study supports the clinical observation that the presentation of affective illness changes with age: manic features predominate in younger children, whereas depressive symptomatology is more evident with pubertal maturation.

Tryptophan hydroxylase gene 218A/C polymorphism is associated with somatic anxiety in major depressive disorder

BACKGROUND

Abnormalities in functioning of the central serotonergic system have been implicated in the pathogenesis of depressive illness and suicidal behavior. Tryptophan hydroxylase (TPH) is the rate-limiting enzyme in the biosynthesis of serotonin, therefore, it may play an important role in regulation or control of serotonin functions. The aim of the present investigation was to determine whether there is an association between TPH gene polymorphism and major depression. particularly in patients with suicidal ideation.

METHODS

A total of 135 unrelated patients suffering from major depressive disorder and 196 normal unrelated controls were included in the study. All controls and patients were Caucasian. A biallelic polymorphism at the tryptophan hydroxylase locus was genotyped.

RESULTS

No significant difference between controls and depressed subjects in TPH gene polymorphism was detected. There was no association between TPH gene polymorphism and suicidal ideation. Total HAMD scores were not different between the genotypes or alleles in patients. However, among the HAMD clusters, somatic anxiety was significantly associated with TPH genotypes and alleles in that patients with 218A/A genotype had a significantly higher somatic anxiety scores compared to other genotypes.

LIMITATION

Potential confounding effect of population stratification can not be excluded. The functional relevance of the TPH gene 218A/C polymorphism is, at present, uncertain.

CONCLUSION

The polymorphism in serotonergic system related genes may be associated with depressive symptoms in major depressive disorder. The results suggest that analysis of clusters that narrow down the phenotype may be more suitable in genetic studies of major depressive illness.

The genetic aetiology of somatic distress

BACKGROUND

Somatoform disorders such as neurasthenia and chronic fatigue syndrome are characterized by a combination of prolonged mental and physical fatigue. This study aimed to investigate the heritability of somatic distress and determine whether this dimension is aetiologically distinct from measures of depression and anxiety.

METHOD

Measures of anxiety, depression, phobic anxiety, somatic distress and sleep difficulty were administered in a self-report questionnaire to a community-based sample of 3469 Australian twin individuals aged 18 to 28 years. Factor analysis using a Promax rotation, produced four factors: depression, phobic anxiety, somatic distress and sleep disturbance. Multivariate and univariate genetic analyses of the raw categorical data scores for depression, phobic anxiety and depression were then analysed in Mx1.47.

RESULTS

Univariate genetic analysis revealed that an additive genetic and non-shared environmental (AE) model best explained individual differences in depression and phobic anxiety scores, for male and female twins alike, but could not resolve whether additive genes or shared environment were responsible for significant familial aggregation in somatic distress. However, multivariate genetic analysis showed that an additive genetic and non-shared environment (AE) model best explained the covariation between the three factors. Furthermore, 33 % of the genetic variance in somatic distress was due to specific gene action unrelated to depression or phobic anxiety. In addition, 74% of the individual environmental influence on somatic distress was also unrelated to depression or phobic anxiety.

CONCLUSION

These results support previous findings that somatic symptoms are relatively aetiologically distinct both genetically and environmentally from symptoms of anxiety and depression.

The relationship of obsessive-compulsive disorder to possible spectrum disorders: results from a family study

BACKGROUND

The familial relationship between obsessive-compulsive disorder (OCD) and "obsessive-compulsive spectrum" disorders is unclear. This study investigates the relationship of OCD to somatoform disorders (body dysmorphic disorder [BDD] and hypochondriasis), eating disorders (e.g., anorexia nervosa and bulimia nervosa), pathologic "grooming" conditions (e.g., nail biting, skin picking, trichotillomania), and other impulse control disorders (e.g., kleptomania, pathologic gambling, pyromania) using blinded family study methodology.

METHODS

Eighty case and 73 control probands, as well as 343 case and 300 control first-degree relatives, were examined by psychiatrists or Ph.D. psychologists using the Schedule for Affective Disorders and Schizophrenia-Lifetime Anxiety version. Two experienced psychiatrists independently reviewed all diagnostic information and made final consensus diagnoses using DSM-IV criteria.

RESULTS

Body dysmorphic disorder, hypochondriasis, any eating disorder, and any grooming condition occurred more frequently in case probands. In addition, BDD, either somatoform disorder, and any grooming condition occurred more frequently in case relatives, whether or not case probands also had the same diagnosis.

CONCLUSIONS

These findings indicate that certain somatoform and pathologic grooming conditions are part of the familial OCD spectrum. Though other "spectrum" conditions may resemble OCD, they do not appear to be important parts of the familial spectrum.

Paradox segmentation along inter- and intrasomitic borderlines is followed by dysmorphology of the axial skeleton in the open brain (opb) mouse mutant

In open brain (opb) mutant embryos, developmental defects of the trunk spinal cord were spatially correlated with severe defects of the epaxial somite derivatives including sclerotomes, whereas hypaxial somite derivatives are much less affected. Later in development, the neural arches (epaxial sclerotome derivatives) formed but were severely disorganized, and also the distal ribs (hypaxial sclerotome derivatives) were malformed. Adjacent neural arches and vertebral bodies were often fused where joints should have formed suggesting defects of the intrasomitic borderlines. Moreover, neural arches frequently and ribs sometimes were split into halves at distinct levels along the dorso-ventral body axis. This suggests that 'resegmentation' of sclerotomes across the somite borders did not completely occur. These prominent skeletal defects were preceded by reduced expression of Pax1 along the intrasomitic borderlines, and incomplete maintenance of somite borders between central sclerotome moieties. The defects of the axial skeleton were accompanied by segmentation defects of the myotomes which were split distally, and also partly fused from adjacent segments across somite borders. The segmentation defects observed suggest that in opb mutants both segmental borderlines, the somite borders and the intrasomitic borderlines (fissures), were affected and behaved paradoxically.

Correlates of hypochondriasis in a nonclinical population

Because few community surveys of hypochondriasis have been completed, little is known about the epidemiology of this disorder outside of clinical populations. To address this deficiency, the authors obtained information about hypochondriasis and pertinent characteristics from a group of first-degree relatives of hypochondriacal and nonhypochondriacal probands who participated in a family study. In addition to psychiatric diagnoses, the authors elicited information on demographic variables, medical history, impairment in functioning, psychiatric comorbidity, psychiatric symptoms, personality traits, and childhood experiences. The authors identified hypochondriasis in 7.7% of the relatives. These relatives had a high rate of comorbid anxiety, depressive, and somatoform disorders. They also reported substantial physical and psychological impairment, including diminished work performance and disability. In addition, these relatives reported greater utilization of health care but less satisfaction with that care. These relatives showed most of the same characteristics found in earlier studies of hypochondriacal patients.

Self-reported depression, familial history of depression and fibromyalgia (FM), and psychological distress in patients with FM

The prevalence of FM in the general population is estimated at 2%. FM is among the three most common diagnoses in ambulatory adult rheumatology practice. To study the degree of depression, the familial history of depression and FM, as well as the psychological distress in our FM population, we mailed a standardized questionnaire to 304 FM patients. The response rate was 33%. We found BDI scores higher than 21 in 27% of the patients indicating clinical relevant depression. The patients had high levels of global distress measured with the SCL-90-R as well as elevated scores in the subscales. Twenty three percent had a familial history of depression, 46% a familial history of FM, and 46% had been diagnosed with depression in the past.

GABAA alpha-1 subunit gene not associated with depressive symptomatology in mood disorders

Considerable evidence implicates the neurotransmitter gamma-aminobutyric acid (GABA) in the biochemical pathophysiology of mood disorders. In this study, we investigated the possibility that the gene for the gamma-aminobutyric acid type A (GABAA) receptor alpha-1 subunit (GABRA1) might be associated with depressive symptomatology in a sample of mood disorder subjects. Sixty-seven inpatients affected by unipolar (n = 37) and bipolar (n = 30) disorder (DSMIV) were assessed at admission by the Hamilton depression rating scale (HAMD) and were typed using polymerase chain reaction (PCR) techniques. GABRA1 variants were not associated with depressive symptomatology, and consideration of possible stratification effects such as sex, psychiatric diagnosis and illness severity did not reveal any association either. GABAA alpha-1 subunit gene is not, therefore, associated with depressive symptomatology in mood disorder subjects.

A family study of hypochondriasis

To examine the diagnostic validity of hypochondriasis, we undertook a preliminary family study. Nineteen probands with and 24 without DSM-III-R hypochondriasis were identified among outpatients attending a general medicine clinic. Seventy-two first-degree relatives of hypochondriasis probands and 97 relatives of control probands were personally interviewed with the use of the Structured Clinical Interview for DSM-IV. These relatives also completed self-administered measures of hypochondriasis, psychological and somatic symptoms, and personality traits. No increase in the rate of hypochondriasis was found among the relatives of hypochondriasis probands compared with the relatives of control probands. With respect to other mental disorders, only somatization disorder was more frequent among the hypochondriacal relatives. These relatives also scored higher on measures of hostility, antagonism, and dissatisfaction with medical care. The findings of this study suggest that hypochondriasis may not be an independent disorder but a variable feature of other psychopathology, one that may include somatization disorder.

Comorbidity of panic and somatization disorder: a genetic-epidemiological approach

Although recent diagnostic systems support the distinctiveness of panic disorder (PD) and somatization disorder, a high level of comorbidity of these two diagnoses has been reported, indicating a need for investigations with external validators. One hundred fifty-nine outpatients with DSM-III-R PD and 76 surgical controls were screened for lifetime presence of DSM-III-R somatization disorder, and the risks for some types of psychiatric disorders in their families were computed. In our sample, 23% of women and 5% of men with PD also had DSM-III-R somatization disorder did not differ from women with PD only in age at onset of panic, agoraphobia, childhood history of separation anxiety, or lifetime diagnoses of other disorders. Familial risks for PD, PD-agoraphobia, and alcohol dependence were significantly higher for families of women with PD and women with PD plus somatization disorder than for controls. The familial risks for antisocial personality (ASP) disorder (a familial indicator for the somatization disorder spectrum of liability, phenomenologically independent from both PD and somatization disorder) were significantly higher for families of women with PD plus somatization disorder than for families of women with PD only or for controls. Application of DSM-IV criteria for somatization disorder substantially decreased the comorbidity with PD. Our data suggest that somatization disorder is not simply a form of PD, and that the two disorders may coexist in the same subject without sharing a common genetic diathesis. Compared with DSM-III-R, DSM-IV criteria for somatization disorder appear to be simpler in structure and of less complicated application.

A twin-family study of self-report symptoms of panic-phobia and somatization

Self-report symptoms of anxiety are widely used in mental health and social science research as an index of current psychiatric state. Previous twin studies have suggested that genetic factors account for a significant proportion of the variance in these symptoms. To replicate and extend these findings, we examined self-report symptoms of panic-phobia and somatization in the "Virginia 30,000" twin-family sample. Model fitting applied to 80 unique relationships in the twin-family pedigree produced the following major results: (i) genetic effects were significant for both symptom factors, accounting for between 25 and 49% of the total variance, with the exception of symptoms of panic-phobia in females, where they accounted for 15-16% of the variance; (ii) familial environmental effects were absent for symptoms of somatization, while for symptoms of panic-phobia they accounted for a very small proportion of variance in males (< or = 1.2%) and a modest proportion in females (6-17%); (iii) spousal correlations were present for both factors, ranging from +0.05 to +0.20; (iv) genetic factors which influenced symptoms were generally the same in males and females, although their effect was greater in males; (v) heritability estimates were lower in the population-based than in the volunteer sample; and (vi) when test-retest reliability was included in the model, results suggest that genetic factors account for at least half of the stable variance for all symptom factors, except panic-phobia in females. Our results support the validity of previous twin studies of self-report symptoms of anxiety and suggest that genetic factors significantly influence these symptoms but familial-environmental factors play little or no etiologic role.

Antecedents of neurosis in a cohort of 30,344 twins in Sweden

We analyzed questionnaire survey responses in a cohort of 30,344 twins in Sweden, 280 of whom became inpatients due to neurosis within the subsequent 10 years. As a group, they differed substantially in their reported health profile from the survey responders who were not admitted for psychiatric treatment. When subclassified into anxiety, depressive, and other neuroses, these were indistinguishable from each other regarding self-perceived health and personality traits. Women were more likely to be hospitalized for neurosis. These mental and social antecedents for both anxiety and depression are in keeping with the concept of a shared diathesis which is supported by neurophysiological, treatment and genetic epidemiological studies.

Clinical characteristics of familial generalized anxiety disorder

The authors seek to determine whether the clinical characteristics of generalized anxiety disorder (GAD) differ in individuals with a high vs. low familial vulnerability to illness. We identified 486 personally interviewed female twins from a population-based register who had both an interviewed co-twin and a lifetime history of GAD using modified DSM-III-R criteria which required a one-month minimum duration of illness. We attempted to predict risk for GAD in the co-twin from the clinical features of the GAD in the proband twin using the Cox proportional hazard model, controlling for year of birth and zygosity. Only two variables uniquely predicted an increased risk for GAD in the co-twin: number of GAD symptoms endorsed and comorbidity with bulimia. Variables that did not uniquely predict risk of illness in the co-twin included age at onset, duration of the longest episode and number of episodes. The familial vulnerability to GAD can be meaningfully indexed by clinical features of the syndrome. These results suggest that if the syndrome of GAD is to be narrowed, it would, from a familial perspective, be more valid to increase the minimum number of required symptoms rather than to increase the minimum duration of illness.

Comparison of screening proposals for somatization disorder empirical analyses

We report a comparison of three sets of screening criteria, plus a post hoc modification of one, for the diagnosis of somatization disorder. Included in the comparison are the DSM-III-R seven-symptom screen, 11 symptoms identified by Swartz et al., and the hierarchical screen using symptom clusters that has been proposed for DSM-IV, along with a modification to the latter. Data sets used in this test were from the St Louis Epidemiologic Catchment Area (ECA) study and a family study of alcoholism. Findings of sensitivity, specificity, and positive predictive value indicate advantages and disadvantages of each screening set. No one set was clearly superior; selection of screening criteria should be dependent on the intended application.