Which disorder is characterized by the presence of obsessions, compulsions, or both?

The disorder characterized by the presence of obsessions, compulsions, or both is Obsessive-Compulsive Disorder (OCD). This condition is marked by intrusive thoughts (obsessions) that cause significant anxiety and are often accompanied by repetitive behaviors or mental acts (compulsions) performed to reduce that anxiety or prevent a feared outcome. Individuals with OCD are typically aware that their thoughts and behaviors are excessive or unreasonable, which can lead to substantial distress and impairment in functioning.

In contrast, Body Dysmorphic Disorder focuses on an excessive preoccupation with perceived flaws in appearance, which does not necessarily involve compulsive behaviors aimed at reducing anxiety surrounding these preoccupations. Hoarding Disorder involves persistent difficulty discarding or parting with possessions, stemming from a perceived need to save them, but does not involve the anxiety-driven actions typical of OCD. Trichotillomania, characterized by the urge to pull out one's hair, is also driven by a compulsion to relieve tension but is more specifically about hair pulling rather than the broader scope of obsessions and compulsions observed in OCD. Thus, OCD is distinct in its specific and defining criteria that include both obsessions and compulsions.