Differential Diagnosis

• Single Most Likely Diagnosis
  • Opioid Use Disorder: The patient's history of using multiple substances, including heroin, and experiencing withdrawal symptoms, tolerance, and difficulty functioning without the substance, strongly suggests opioid use disorder. The patient's recent increase in dosage and use of kratom as a substitute when heroin is not available further supports this diagnosis.
• Other Likely Diagnoses
  • Major Depressive Disorder: The patient reports feelings of depression, hopelessness, and lack of purpose, which have been ongoing for over a year. The patient's symptoms, such as feeling mentally drained, canceling plans, and not wanting to get out of bed, are consistent with major depressive disorder.
  • Post-Acute Withdrawal Syndrome (PAWS): The patient's history of substance use and recent withdrawal symptoms, such as runny nose, teary eyes, and achy body feelings, may indicate PAWS.
  • Anxiety Disorder: The patient reports feeling anxious, particularly when he is unable to access substances, which may indicate an underlying anxiety disorder.
  • Adjustment Disorder: The patient's difficulty adapting to his new environment in Vermont and his struggles with finding purpose in life may suggest an adjustment disorder.
• Do Not Miss Diagnoses
  • Suicidal Ideation: Although the patient denies any current suicidal ideation, his history of suicidal thoughts after dropping out of college and his current struggles with depression and substance use warrant careful monitoring for suicidal ideation.
  • Bipolar Disorder: The patient's history of substance use and depressive episodes may mask underlying bipolar disorder. Although he denies any history of mania or hypomania, it is essential to consider this diagnosis due to the potential for substance use to trigger or worsen bipolar symptoms.
• Rare Diagnoses
  • Dysthymia: The patient was previously diagnosed with dysthymia, but this diagnosis is less likely given the patient's current symptoms and substance use history.
  • Post-Traumatic Stress Disorder (PTSD): Although the patient's history of his father's infidelity and his subsequent drop out of college may have been traumatic, there is no clear indication of PTSD symptoms, such as flashbacks or nightmares. However, this diagnosis should be considered if the patient reports any traumatic symptoms or experiences.