This issue contains a review of the acceptability of computerized cognitive behaviour therapy for depression, and papers on various aspects of depression and anxiety, psychosis, and attention deficit hyperactivity disorder. Five individual papers examine a variety of topics, and this issue concludes with a report on a conference to discuss the future of diagnoses of depression and generalized anxiety disorder.
Computerized cognitive behaviour therapy
In the first paper, Kaltenthaler et al. (pp. 1521–1530) report findings from a systematic review of sources of information on the acceptability to patients of computerized cognitive behaviour therapy (CCBT) for depression. In the 16 identified studies, the authors found limited information on indicators of acceptability (e.g. recruitment, take-up and drop-out rates). Where available, drop-out rates for CCBT were similar to other forms of treatment, but take-up rates were lower. The authors conclude that trials of CCBT need to collect more detailed information on indicators of acceptability to patients.
Depression and anxiety
In the first of four papers on various aspects of depression and anxiety, Quilty et al. (pp. 1531–1541) assessed evidence for a cognitive mediation model of CBT in a randomized controlled trial of CBT, interpersonal therapy (IPT) and pharmacotherapy (PHT) involving 130 patients with major depressive disorder (MDD). The authors found no evidence for a mediational role for dysfunctional attitude change in IPT. There was, however, evidence that dysfunctional attitudes mediated symptom reduction in response to treatment with CBT, when contrasted with IPT. The reverse was true for CBT when contrasted with PHT, i.e. evidence that depressive symptoms mediated dysfunctional attitude change.
Warner et al. (pp. 1543–1556) investigated whether anxiety disorders associated with fear (phobia, panic) and anxiety (overanxious, generalized anxiety disorder) mediated the relationship between parental and offspring depression in a longitudinal cohort of 224 second-generation and 155 third-generation descendants of parents with depression. The authors found evidence that fear- (but not anxiety-) related disorders mediated the association between parental MDD and offspring MDD in second- and third-generation offspring. These effects were most evident in adolescent-onset MDD.
Middeldorp et al. (pp. 1557–1565), in a sample of 5782 twins from the longitudinal Norwegian Twin Register, examined: (a) unidirectional and reciprocal causality, and gene–environment correlation, models of the association between life events and anxious depression; and (b) associations between life events and personality (neuroticism and extraversion). The authors found that anxious depression and neuroticism both increased after exposure to life events and, prospectively, predicted life events, i.e. evidence of reciprocal causation. There was no evidence that extraversion was related to life events, and no evidence of gene–environment correlation.
Kendler et al. (pp. 1567–1575) investigated patterns of genetic and environmental influences on symptoms of anxiety and depression from childhood to early adulthood in 2508 twins assessed at ages 8–9, 13–14, 16–17 and 19–20 years as part of the Swedish Twin Study of Child and Adolescent Development. The authors found that the best fit model revealed one genetic risk factor for such symptoms at all ages, with other genetic risk factors ‘coming on line’ from early adolescence onwards. Heritability estimates for symptoms of anxiety and depression ranged from 72% to 89%. No evidence was found for shared environmental influences.
Psychosis
In the first of two papers examining aspects of psychosis, Corcoran et al. (pp. 1577–1583) investigated whether two psychological anomalies (a tendency to ‘jump to conclusions’ and poor theory of mind) were evident, independent of diagnosis, in a sample of 88 individuals with current or previous persecutory delusions (PD) and 27 with MDD with no history of persecutory delusions. The authors found a tendency to jump to conclusions and poor theory of mind, assessed using a story format, in all the PD groups, irrespective of diagnosis. Poor performance on the non-verbal theory-of-mind task was specific to those with a schizophrenia spectrum disorder.
Malla et al. (pp. 1585–1593) examined predictors of relapse over a 2-year period in a sample of 189 consecutive first-episode psychosis patients treated in a specialist early intervention service in Canada. The authors found that, over the follow-up, 145 (77%) achieved remission of psychosis. Medication adherence was high (85%) and relapse rates low (30%). A higher relapse rate was associated with a co-morbid diagnosis of substance abuse (OR=2.8). The authors conclude that specialist treatment of substance abuse, in early intervention services, may further reduce risk of relapse.
Attention deficit hyperactivity disorder
Two papers examine aspects of attention deficit hyperactivity disorder (ADHD). Rommelse et al. (pp. 1595–1606), in a study of 238 ADHD families (545 children) and 147 control families (271 children), investigated: (a) whether executive functioning (EF) and IQ are viable endophenotypes for ADHD and (b) whether EF and IQ co-segregate within families. The authors found that children with ADHD and their siblings were impaired on EF and verbal (but not performance) IQ. Correlations were not significant between EF and IQ. Further, group differences on EF were not explained by group differences on IQ, and vice versa. The authors conclude that their findings support both the use of EF and IQ as endophenotypes for ADHD and an independent familial segregation of both domains.
Schwartz & Verhaeghen (pp. 1607–1616) examined whether response inhibition is sensitive to ADHD status, and the effect of maturation on this, in a meta-analysis of 25 studies reporting data on the Stroop colour word test in children and adults with ADHD and controls (average ages ranged from 9 to 41 years). From their analyses, the authors did not find evidence that the Stroop interference effect was larger in those with ADHD compared with controls. In addition, there was no evidence for differential maturation rates for those with ADHD compared with controls.
Other topics
Five papers examine a range of other topics. Torgersen et al. (pp. 1617–1625) investigated the relative impact of genetic and environmental factors on the occurrence and co-occurrence of cluster B personality disorders [antisocial (ASPD), histrionic (HPD), narcissistic (NPD), and borderline (BPD)] in 1386 Norwegian twin pairs aged 16–35 years. The authors found that the best fitting model included common genetic and environmental factors influencing all four PD types and further factors influencing only ASPD and BPD. Heritability estimates ranged from 24% for NPD to 38% for ASPD.
Michon et al. (pp. 1627–1637) examined the impact of mental disorders and personality characteristics (neuroticism, locus of control, self-esteem) on work functioning in a sample of 3570 working people drawn from the prospective Netherlands Mental Health Survey and Incidence Study. The authors found that high neuroticism, more external locus of control, and low self-esteem were associated with impairment in work functioning, independent of mental disorder. Associations between mental disorder and work functioning were no longer significant when personality characteristics were controlled.
He et al. (pp. 1639–1650) investigated the prevalence of mental disorder among people with arthritis, using data from the World Mental Health Surveys, a series of cross-sectional studies in 17 centres. The authors found that the prevalence of mood and anxiety disorders was higher in those with arthritis, after adjusting for age and sex (OR=1.9). This held across all centres. Alcohol abuse/dependence had less consistent associations with arthritis.
Roussos et al. (pp. 1651–1658), in a sample of 93 healthy males, examined possible genetic effects on prepulse inhibition (PPI), in particular focusing on the catechol O-methyltransferase (COMT) Val58Met polymorphism, the main catabolic pathway of released dopamine (DA) in the prefrontal cortex. The authors found that Val/Val individuals had the lowest PPI, Met/Met the highest, and Val/Met were intermediate. The authors conclude that PPI is regulated by DA neurotransmission in the prefrontal cortex and dependent on COMT.
Scott et al. (pp. 1659–1669) investigated whether the relationship between age and mental disorders varies as a function of physical co-morbidity using data from the World Mental Health Surveys (n=42 697). The authors found that depressive and anxiety disorders decreased with age, but no difference was found in the relationship between mental disorder and age as a function of physical co-morbidity. The authors further found that the majority of persons with a mental disorder have a co-morbid physical problem, from which they argue for greater attention to be paid to physical health needs by mental health professionals.
Conference report
In the final contribution, Goldberg (pp. 1671–1675) provides a report from a conference on the future of the diagnoses of depression and generalized anxiety disorder (GAD). Evidence was presented for shared and distinct risk factors and characteristics for both disorders. Goldberg notes that the general agreement was that, despite notable overlaps, depression and GAD are not the same disorder and cannot be usefully merged into a single diagnostic category.
