Differential Diagnosis
- Single Most Likely Diagnosis
- Obsessive-Compulsive Disorder (OCD): The patient's preoccupation with being infected with HIV, ritual cleaning, and history of taking SSRIs and CBT suggest a diagnosis of OCD. The fact that symptoms have persisted despite treatment and are interfering with daily life (e.g., completing college) further supports this diagnosis.
- Other Likely Diagnoses
- Anxiety Disorder: The patient's excessive worry about being infected with HIV and ritual cleaning behaviors may also be indicative of an anxiety disorder, such as generalized anxiety disorder or a specific phobia.
- Tic Disorder: The patient's history of motor tics in high school, which improved with marijuana use, suggests a possible tic disorder, such as Tourette's syndrome.
- Depressive Disorder: The patient's disheveled and unkempt appearance, as well as their inability to complete college due to symptoms, may indicate a depressive disorder, such as major depressive disorder.
- Do Not Miss Diagnoses
- Psychotic Disorder: Although the patient does not appear to have any psychotic symptoms, it is essential to rule out a psychotic disorder, such as schizophrenia, as these conditions can be deadly if left untreated.
- Substance Use Disorder: The patient's history of using marijuana to self-medicate for motor tics raises the possibility of a substance use disorder, which can have severe consequences if left untreated.
- HIV Infection: Given the patient's preoccupation with being infected with HIV, it is crucial to rule out actual HIV infection, which can be deadly if left untreated.
- Rare Diagnoses
- Body Dysmorphic Disorder: The patient's preoccupation with being infected with HIV may be related to body dysmorphic disorder, a condition characterized by excessive concern about a perceived flaw in one's appearance.
- Hypochondriasis: The patient's excessive worry about being infected with HIV may also be indicative of hypochondriasis, a condition characterized by excessive fear of having a serious illness.
- Neurodevelopmental Disorder: The patient's history of motor tics and ritual cleaning behaviors may be related to a neurodevelopmental disorder, such as autism spectrum disorder or attention-deficit/hyperactivity disorder.