Being suspicious is not obsessive-compulsive disorder (OCD). Suspiciousness refers to a negative state of mind characterized by nervous hypersensitivity and unfounded suspicion. People with a suspicious mindset often carry preconceived notions. They piece together unrelated events in life through imagination or fabricate certain events out of thin air to confirm their own opinions. As a result, they misinterpret others' unintentional behaviors as being hostile towards them. Without sufficient evidence, they suspect that others are deceiving, harming, or scheming against them, and may even misinterpret others' goodwill as malice. In severe cases, it may even lead to a bitter feud. On the other hand, OCD is a group of neuropsychiatric disorders mainly manifested by obsessive thoughts and compulsive behaviors. Therefore, being suspicious is not OCD.