Psychosis continuum

In the first paper, van Os et al. (pp. 179–195) report findings from a systematic review and meta-analysis of research on aspects of the psychosis continuum, including the prevalence, incidence, and correlates of psychosis-like experiences in the general population. They found strong evidence that such experiences are common in the general population, with a median prevalence of 5% and a median incidence of 3%. In the majority of cases, subclinical psychosis-like experiences are transitory. However, such experiences are associated with an increased risk of clinical disorder, and the authors further found that persistence of experiences and transition to clinical disorder are dependent on exposure to additional environmental exposures, most likely in interaction with genetic risk.

Salience and psychosis

Jensen & Kapur (pp. 197–198) comment on the paper by Roiser et al. in this issue on salience and psychosis. In addition to noting recent studies conducted at both behavioural and neurobiological levels that provide support for a role for aberrant salience in the formation of delusions, the authors emphasize the need for further research to replicate and extend these initial findings. In particular, the authors argue that the real challenge is to translate the theory and initial findings into practical interventions that will benefit patients.

In the paper itself, Roiser et al. (pp. 199–209) investigated aberrant salience by assessing whether a sample of 20 medicated cases with schizophrenia, when compared with 17 controls, showed impaired learning of task-relevant stimulus-reinforcement associations in the presence of task-irrelevant cues. The authors found that patients showed reduced adaptive salience compared with controls. Overall, patients did not differ from controls in terms of aberrant salience. However, patients with delusions showed greater aberrant salience than those without. In addition, aberrant salience was associated with negative symptoms.

Depression and mood

In the first of two papers on aspects of depression and mood, Bogdan & Pizzagalli (pp. 211–218) present findings from a proof of concept study designed to assess the heritability of, and genetic and environmental effects on, two proposed depressive phenotypes – anhedonia (hedonic capacity) and stress-sensitivity (stress perception). In a sample of 20 monozygotic and 15 dizygotic twin pairs, the authors found that additive genetic and individual-specific environmental factors each contributed to around 50% of the variance in hedonic capacity and stress perception. The genetic correlation between depression and hedonic capacity was moderate; that between depression and stress perception and between hedonic capacity and stress perception was large. The authors conclude that these findings support the feasibility of using a twin approach to investigate genetic contributions to an anhedonic phenotype.

Kuehner et al. (pp. 219–228) investigated the effects of induced rumination, distraction and mindful self-focus on mood, dysfunctional attitudes and cortisol responses in a sample of 60 students. The authors found that the distraction condition had a clear beneficial effect on dysphoric mood, compared with induced rumination. Further, those induced to ruminate showed notable increases in dysfunctional attitudes compared with distraction and mind self-focus conditions. The authors conclude that rumination can maintain depression-linked dysfunctional thought content. In addition, participants who were induced to ruminate and who scored highly on the Beck Depression Inventory (BDI) showed smaller decreases in cortisol levels than those scoring low on the BDI.

Anxiety

In the first of five papers on aspects of anxiety, Smits & Hofmann (pp. 229–239) examined the magnitude of improvement associated with psychotherapy control conditions for adult anxiety disorders in a meta-analysis of 19 studies. The authors found that psychotherapy control conditions are associated with significant improvements in anxiety and with relatively low attrition rates. There was no evidence of publication bias. The authors conclude that such findings should inform the design of future psychotherapy outcome studies.

Acarturk et al. (pp. 241–254) present findings from a meta-analysis of 29 randomized studies of the effectiveness of psychological treatments for social anxiety. The authors found mean effect sizes for treatments on social anxiety measures of 0.7, on cognitive measures of 0.8, and on depression and general anxiety of 0.7. There was evidence of heterogeneity, with studies using waiting-list control groups showing larger effect sizes than those using placebo and treatment-as-usual groups. Studies restricted to those meeting DSM criteria for social anxiety disorder had smaller effects. The authors conclude that psychological treatments for social anxiety are effective, but that this may be less so in those with more severe disorder.

Barrett & Armony (pp. 255–265) investigated how individual differences in trait anxiety influence neural responses associated with the acquisition and extinction of anticipatory anxiety elicited through a conditioning paradigm. In 18 healthy volunteers who completed decision-making tasks while undergoing functional magnetic resonance imaging, the authors found increased responses in the amygdale to aversive stimuli during acquisition and extinction sessions, and increased responses in the anterior cingulate cortex to aversive stimuli during extinction sessions. Higher levels of trait anxiety were associated with higher conditioned responses in the amygdala during extinction.

Nicolini et al. (pp. 267–276) examined the efficacy and tolerability of duloxetine and venlafaxine extended-release treatment for generalized anxiety disorder in a 10-week double-blind, placebo-controlled trial (placebo, n=170; 20 mg duloxetine, n=84; 60–120 mg duloxetine, n=158; venlafaxine, n=169). The authors found that each of the three active treatment groups had improved total scores on the Hamilton Anxiety Rating Scale and improved psychic factor scores, compared with the placebo group. Both the 60–120 mg duloxetine and venlafaxine (but not 20 mg duloxetine) groups had improved somatic factor scores compared with the placebo group.

Ferguson (pp. 277–285) investigated the extent to which health anxiety is a dimensional or categorical construct in a sample of 711 working adults who completed an index of health anxiety and indicated their current health status. On the basis of a series of analyses using three different taxometric procedures (mean above minus below a cut, maximum eigenvalue, L-mode factor analysis), Ferguson found that health anxiety is more accurately represented as a dimensional rather than a categorical construct.

Other topics

In the first of the final five papers, Suvisaari et al. (pp. 287–299) examined the prevalence and correlates of, and related service contacts for, common mental disorders in a nationally representative two-stage cluster sample of 1863 Finns aged 19–34 years. The authors found a 40% lifetime prevalence of at least one DSM-IV Axis I disorder, the most common being depression (18%), substance abuse/dependence (14%) and anxiety disorders (13%). Of those with a lifetime disorder, over 50% had more than one disorder. Lower education and unemployment were strongly associated with having a disorder. Only 24% of those with a current disorder were receiving treatment at the time of the study.

Goodwin et al. (pp. 301–311) examined the relationship between mental health problems in childhood at age 8 years and physical disorders in adulthood at ages 18–23 years in a sample of 2712 subjects. The authors found strong evidence that childhood mental disorders were associated with obesity, atopic eczema, epilepsy and asthma in early adulthood. There was, moreover, some evidence of specificity, with conduct problems being associated with obesity and atopic eczema, emotional problems with epilepsy and asthma, and depression with asthma. The authors conclude that early mental health problems may signify vulnerability to physical health problems in early adult life.

Burns et al. (pp. 313–323) sought to operationalize and test a multi-axial model of continuity of care comprising eight facets in a sample of 180 service users. Using factor analysis to determine the validity of the model for severe mental disorder, the authors found that seven independent continuity factors accounted for 63% of the variance: experience and relationship; regularity; meeting needs; consolidation; managed transitions; care coordination; and supported living. These factors were similar, but not identical, to the original model. The authors conclude that these factors should be used as a starting point for future research examining the determinants and outcomes of continuity of care in severe mental disorder.

Tolin et al. (pp. 325–336) examined the neural underpinnings of decision-making abnormalities in a sample of 12 adult patients diagnosed with compulsive hoarding and 12 matched healthy controls. Subjects underwent functional magnetic resonance imaging while making decisions about whether to discard personal items. The authors found that, when making such decisions, patients displayed excessive haemodynamic activity in lateral orbitofrontal cortex and parahippocampal gyrus. Within the patient group, a decision to retain a possession was associated with greater activity in a number of brain regions, including the superior temporal gyrus, the anterior cingulated cortex and cerebellum.

In the final paper, Hallahan et al. (pp. 337–346) investigated head size and the bulk volume of ventricular and peripheral cerebrospinal fluid (CSF), lobar brain, and cerebellum in a sample of 114 adults with autistic spectrum disorder (ASD) and 60 controls aged between 18 and 58 years. The authors found no differences between cases and controls in head and/or lobar brain-matter volume. However, the ASD group did have a significantly smaller cerebellar volume and a significantly larger peripheral CSF volume compared with controls.