Very-late-onset obsessive-compulsive disorder (VLO-OCD) is rather rare. Although VLO-OCD should prompt a thorough workup, most cases do not evidence an underlying medical illness nor structural brain abnormality. A subset manifests somatic obsessions, bringing about diagnostic challenges.

Critical literature review based on a case study.

A 73-year-old male patient, was hospitalized for intrusive, repeated, distressing mental images and thoughts about hell, describing difficulty to disengage from these obsessions, alongside secondary mystical and ruin delusion-like ideas, modulated by the pathoplastic effect of core religious beliefs, and inflated sense of responsibility. He had previously experienced those intrusive mental images, yet not in a recurrent nor uncontrollable manner.

Preceding the OCD, he presented mild depressive symptoms triggered by financial hardships. After the emergence of OCD, depressive disorder aggravated, with psychomotor retardation, hopelessness, insomnia, anorexia. Obsessive hyperawareness of autonomic processes, distressing body-focused preoccupations raised by interoceptive stimuli, became noticeable, with overestimation of threatening consequences, day-long swallowing rituals/compulsions, avoidance of nutritional intake, general unease, and even panic. Yale-Brown Obsessive Compulsive Scale (Y-BOCS) scored 25. Ancillary tests were unremarkable. Transglutaminase antibodies were negative, ruling out gluten-sensitive enteropathy, hence tryptophan-serotonin metabolism impairment. Neuroimaging did not evidence structural disruption of cortico-striatal circuitry. Therapeutic regimen comprised sertraline 200 mg/day, augmented with mirtazapine 45 mg/day, aripiprazole 15 mg/day. Additionally, trazodone, buspirone and benzodiazepines were used to manage anxiety and insomnia. At the fourth week of treatment the anxiety burden driven by religious obsessions ameliorated. Meanwhile lamotrigine 100 mg/day and gabapentine 200 mg/day were added with further improvement (60% Y-BOCS score reduction, at seventh week).

This case highlights the clinical relevance of the OC spectrum concept, wherein at the compulsive end are OCD-related disorders which feature high degrees of harm avoidance, intolerance to uncertainty, anticipatory anxiety, engagement in repetitive behaviors. We hypothesize that somatoform variant of OCD constitutes a distinct phenotypic subtype, stemming from a complex interplay of neurobiological substrates, psychosocial, and genetic factors, shared with hypochondriasis. This assumption might be addressed in future studies.

Furthermore, this case illustrates the fact that VLO-OCD might exhibit prodromic periods of subclinical OC symptoms before the manifestation of full-blown OCD.