Approaches to the Diagnosis and Treatment of OCD with Comorbid Tic Disorders

Abstract

Bidirectional overlap has long been described between obsessive–compulsive disorder (OCD) and tic disorders. Similar features, including underlying neurobiological genesis in frontal-striatal circuitry, familiality, relatively early onset, waxing and waning course, and overlapping phenomenology in repetitive behaviors, suggest different variations of the same disorder. Nevertheless, some differences have been described between OCD and tic disorders: tics begin early in childhood and typically attenuate or remit by late adolescence, whereas OCD tends to onset later and persist, and tic disorders are far more common in males than is the case in OCD. Individuals with OCD plus comorbid tics may represent a specific sub-type of OCD or tic disorders, and possess some important phenomenological differences from those with OCD without tics; for example, tic-related OCD tends to have earlier onset, higher prevalence in males, prominent symmetry, evening-up, counting, and “just-right” phenomenology, when compared with non-tic-related OCD. Recent DSM-5 classification changes now recognize presence of tics as a specifier in diagnosis of OCD; despite a 40 % prevalence rate of comorbid tics in childhood-onset OCD, there is still little data regarding risk factors, validated distinguishing features, course and treatment of this diagnostic group. Prominence of premonitory sensory phenomena, urges or sensations experienced prior to the repetitive behaviors, is no longer thought to distinguish complex motor tics from compulsions. Well established treatments of OCD include cognitive behavioral interventions and pharmacotherapy, specifically the serotonin re-uptake inhibitors (SRIs); although these treatments are also beneficial in tic-related OCD, some studies suggest that at least for pharmacotherapy, SRIs may not be as effective in OCD patients with comorbid tics. Given the frequent overlap of OCD and tics, and the recent designation of tic-related OCD as an OCD specifier, more investigation of the comorbid subtype is clearly needed.