Obsessive-compulsive spectrum of disorders: a defensible construct?

Own-body perception in body dysmorphic disorder

INTRODUCTION

This paper reviews the literature as it relates to perceptual processes in body dysmorphic disorder (BDD).

METHODS

A narrative-style review of the literature was undertaken to explore the relationship between BDD and obsessive-compulsive disorder, the empirical evidence for aberrant own-body perception in BDD, and the possible role of the parietal cortex in the disorder.

RESULTS

The extant literature appears to support the postulation that BDD is underpinned by a dysfunction in somatoperception-the process by which individuals formulate a sense of what they look like.

CONCLUSIONS

Investigation of somatoperceptive processes in BDD and related brain structures would provide important insight about the development and maintenance of this complex and often neglected psychiatric condition, and, in turn, help improve its treatment.

Pathological gambling and compulsive buying: do they fall within an obsessive-compulsive spectrum?

Both compulsive buying (CB) and pathological gambling (PG) have been proposed as members of a spectrum of disorders related to obsessive-compulsive disorder (OCD). The spectrum hypothesis originated in the early 1990s and has gained considerable support, despite the lack of empirical evidence. Interest in this hypothesis has become critical because some investigators have recommended the creation of a new category that includes these disorders in DSM-5, now under development. In this article, the authors describe the origin of the obsessive-compulsive (OC) spectrum and its theoretical underpinnings, review both CB and PG, and discuss the data both in support of and against an OC spectrum. Both disorders are described in terms of their history, definition, classification, phenomenology family history, pathophysiology, and clinical management. The authors conclude that: (i) CB and PG are probably not related to OCD, and there is insufficient evidence to place them within an OC spectrum in DSM-V; (ii) PG should stay with the impulse-control disorders (ICDs); and (iii) a new diagnosis of CB should be created and be classified as an ICD.

Obsessive-compulsive disorder and its related disorders: a reappraisal of obsessive-compulsive spectrum concepts

Obsessive-compulsive disorder (OCD) is a clinical syndrome whose hallmarks are excessive, anxiety-evoking thoughts and compulsive behaviors that are generally recognized as unreasonable, but which cause significant distress and impairment. When these are the exclusive symptoms, they constitute uncomplicated OCD. OCD may also occur in the context of other neuropsychiatric disorders, most commonly other anxiety and mood disorders. The question remains as to whether these combinations of disorders should be regarded as independent, cooccurring disorders or as different manifestations of an incompletely understood constellation of OCD spectrum disorders with a common etiology. Additional considerations are given here to two potential etiology-based subgroups: (i) an environmentally based group in which OCD occurs following apparent causal events such as streptococcal infections, brain injury, or atypical neuroleptic treatment; and (ii) a genomically based group in which OCD is related to chromosomal anomalies or specific genes. Considering the status of current research, the concept of OCD and OCD-related spectrum conditions seems fluid in 2010, and in need of ongoing reappraisal.

Brain response to visual sexual stimuli in homosexual pedophiles

OBJECTIVE

The neurobiological mechanisms of deviant sexual preferences such as pedophilia are largely unknown. The objective of this study was to analyze whether brain activation patterns of homosexual pedophiles differed from those of a nonpedophile homosexual control group during visual sexual stimulation.

METHOD

A consecutive sample of 11 pedophile forensic inpatients exclusively attracted to boys and 12 age-matched homosexual control participants from a comparable socioeconomic stratum underwent functional magnetic resonance imaging during a visual sexual stimulation procedure that used sexually stimulating and emotionally neutral photographs. Sexual arousal was assessed according to a subjective rating scale.

RESULTS

In contrast to sexually neutral pictures, in both groups sexually arousing pictures having both homosexual and pedophile content activated brain areas known to be involved in processing visual stimuli containing emotional content, including the occipitotemporal and prefrontal cortices. However, during presentation of the respective sexual stimuli, the thalamus, globus pallidus and striatum, which correspond to the key areas of the brain involved in sexual arousal and behaviour, showed significant activation in pedophiles, but not in control subjects.

CONCLUSIONS

Central processing of visual sexual stimuli in homosexual pedophiles seems to be comparable to that in nonpedophile control subjects. However, compared with homosexual control subjects, activation patterns in pedophiles refer more strongly to subcortical regions, which have previously been discussed in the context of processing reward signals and also play an important role in addictive and stimulus-controlled behaviour. Thus future studies should further elucidate the specificity of these brain regions for the processing of sexual stimuli in pedophilia and should address the generally weaker activation pattern in homosexual men.

Not by genes alone: New hope for prevention

New understanding of the etiology of mental disorders calls for a revised look at psychiatric research priorities. Current research efforts are focused on the search for biogenetic causes of mental disorders. However, a small but growing body of research is revealing the inextricable relationship between genes and environment. The article questions the prevailing assumption that biogenetic factors are more fundamental than co-occurring psychosocial factors. The article synthesizes findings from clinical studies and gene-environment literature to illuminate the role of psychosocial adversity and other environmental stressors as primary etiological factors interacting with genetic vulnerabilities in the development of mental disorders. Applying this understanding of etiology combined with recent advances in prevention research methods offers new promise of positive dividends from investments in primary prevention.