Medicinal plants for obsessive-compulsive disorder: A review of phytotherapeutic approaches

Obsessive-compulsive disorder (OCD) is a chronic psychiatric condition characterized by intrusive thoughts and repetitive behaviors that impair functioning. Although selective serotonin reuptake inhibitors (SSRIs) and cognitive behavioral therapy are first-line treatments, 40-60% of patients achieve only partial remission, with persistent symptoms and adverse effects. This highlights the need for alternative approaches such as phytotherapy, which has shown potential neuroprotective and neurotransmitter-modulating properties.

A structured narrative review with a systematic search was conducted across PubMed, Scopus, Web of Science, and Google Scholar up to April 2025. Studies evaluating medicinal plants or phytochemicals in OCD or OCD-like behavior were included. Both preclinical in vivo and human studies were assessed. A total of 26 studies (14 preclinical, 12 clinical) were included and appraised using a multi-domain quality framework and evidence hierarchy.

Preclinical studies indicated that several plant-derived compounds influence serotonergic, dopaminergic, and GABAergic systems and reduce OCD-like behaviors. However, most relied on non-specific models such as marble-burying, limiting interpretability. Clinical evidence was limited, with few randomized controlled trials and several low-quality or observational studies. While some interventions showed symptom improvement, methodological weaknesses and small sample sizes reduced reliability.

Current evidence does not support clinical recommendations for phytotherapy in OCD. Findings remain preliminary and hypothesis-generating. Future research should focus on well-designed clinical trials, standardized formulations, and translationally valid models to establish efficacy and safety.