Differential Diagnosis

The patient's symptoms and history suggest a complex interplay of psychiatric and substance-related issues. The following differential diagnosis is organized into categories to guide further evaluation and treatment.

• Single Most Likely Diagnosis
  • Major Depressive Disorder (MDD) with Substance Use Disorder: The patient's reported depressive episodes, feelings of hopelessness, lack of purpose, and motivational issues are consistent with MDD. The use of substances such as heroin, soma, and kratom, and the difficulty in functioning without them, indicate a substance use disorder. The patient's history of brief therapy and lack of psychiatric intervention or medication suggest untreated or undertreated depression.
• Other Likely Diagnoses
  • Substance-Induced Depressive Disorder: The patient's depressive symptoms may be induced or exacerbated by substance use, particularly heroin.
  • Post-Acute Withdrawal Syndrome (PAWS): The patient's reported withdrawal symptoms, such as runny nose, teary eyes, and achy body feelings, may be indicative of PAWS, which can contribute to depressive symptoms and substance use.
  • Social Anxiety Disorder: The patient's reported social anxiety and avoidance behaviors, such as canceling plans and not wanting to get out of bed, suggest social anxiety disorder.
  • Bipolar Disorder: The patient's reported depressive episodes and substance use may be indicative of bipolar disorder, particularly if the patient experiences manic or hypomanic episodes.
• Do Not Miss Diagnoses
  • Suicidal Ideation: Although the patient reported occasional thoughts of self-harm, it is essential to assess for suicidal ideation and intent, as the patient's depressive symptoms and substance use increase the risk of suicide.
  • Overdose Risk: The patient's heroin use and history of substance use disorder increase the risk of overdose, which can be fatal if not addressed.
  • Infectious Diseases: The patient's injection drug use increases the risk of infectious diseases, such as HIV, hepatitis, and endocarditis.
• Rare Diagnoses
  • Post-Traumatic Stress Disorder (PTSD): Although not explicitly reported, the patient's substance use and depressive symptoms may be related to underlying trauma, which could be indicative of PTSD.
  • Attention-Deficit/Hyperactivity Disorder (ADHD): The patient's reported difficulty with motivation and focus may be indicative of ADHD, particularly given the family history of substance use and potential genetic predisposition.
  • Neurodegenerative Disorders: The patient's reported cognitive and motivational issues may be indicative of a neurodegenerative disorder, such as early-onset dementia or Parkinson's disease, although this is less likely given the patient's age and presentation.