In the most severe cases of OCD, patients may have uncontrollable redundant associations and behaviors that make it impossible to continue their daily activities, resulting in complications of anxiety and depression, cognitive impairment, loss of social functioning, and even suicidal tendencies. 1. Depression and anxiety symptoms, the severity of which can be proportional to the severity of OCD; 2. Cognitive impairment: OCD patients have certain memory impairments (such as visual memory, spatial recollection, and other memory focusing on the whole), attention deficits, and executive dysfunction due to obsessive-compulsive ideas and excessive attention to details of events. Patients’ thoughts are often interrupted and they are unable to carry out complete recall, analysis and other thinking processes. 3. Loss of social functions: Patients with OCD are unable to continue their normal lives and daily arrangements cannot be implemented smoothly due to their repetitive behaviors. It may also lead to loss of social functions because of frequent unnecessary associations, constituting causal relationships between some daily events and catastrophic imaginations in the brain, and the inability to participate in normal work and social life; 4. Suicidal tendencies: Patients with OCD with the abnormal manifestations mentioned above may lead to suicidal tendencies and even cause death. If a patient has OCD, no matter to what extent, it is recommended to seek timely medical treatment to receive psychological intervention as well as medication to avoid delaying the condition and causing serious consequences.