Among the current treatments for obsessive-compulsive disorder (OCD), cognitive-behavioral therapy (CBT) has proven effective in improving outcomes by achieving remission or strengthening response prevention. However, pharmacotherapy intervention, such as SSRI treatment, may support the introduction of CBT by helping to alleviate elevated anxiety and increase treatment motivation, making it indispensable for maximizing patient adherence and therapy effectiveness. To overcome the apparent limitations of current pharmacotherapy for OCD, cross-sectional or longitudinal evaluations should be made at the individual level among OCD patients Such evaluations should focus comprehensively on psychopathological features, such as primary or secondary comorbid disorders, or temporal transition of the brain mechanism according to the duration of untreated or chronicity of OCD. Furthermore, these clinical factors should be taken into account when considering adequate treatment regimens for OCD patients who respond insufficiently to the standardized pharmacotherapy for OCD. Additionally, the consideration of such cross-sectional and longitudinal heterogeneity of OCD may be crucial to making progress in the exploration of the biological mechanism underlying OCD, and to developing more effective treatment strategies for OCD. For the treatment-refractory OCD patients, especially, novel individualized treatment approaches could include adaptation of glutamatergic agents or neuromodulation.
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