Differential Diagnosis
- Single most likely diagnosis
- Conduct Disorder: This diagnosis is the most likely due to the patient's history of aggressive behavior (suspicious fire at the local park), deceitfulness (going to a party without telling his parents), and reckless disregard for others' safety (playing with matches and starting a fire). His current behavior of talking back and arguing with his parents, as well as finding a cigarette lighter in his pocket, further supports this diagnosis.
- Other Likely diagnoses
- Oppositional Defiant Disorder (ODD): The patient's pattern of angry/irritable mood, argumentativeness, and vindictiveness towards his parents could suggest ODD. However, the presence of more severe behaviors such as starting fires and deceitfulness leans more towards Conduct Disorder.
- Attention Deficit Hyperactivity Disorder (ADHD): Although not directly mentioned, the patient's history of playing with matches and starting a fire "just to see" could indicate impulsivity, a key feature of ADHD. However, there is not enough information to confirm this diagnosis.
- Do Not Miss diagnoses
- Bipolar Disorder: Although less likely, it's crucial to consider bipolar disorder due to the patient's history of impulsive and reckless behavior (starting fires). Manic or hypomanic episodes can manifest as increased impulsivity and reckless behavior, which could be deadly if missed and left untreated.
- Substance Use Disorder: Finding a cigarette lighter in the patient's pocket, despite his denial of smoking, raises concerns about potential substance use. Early intervention is critical in adolescent substance use disorders to prevent long-term consequences.
- Rare diagnoses
- Pyromania: This diagnosis involves deliberate and purposeful fire-setting on more than one occasion. Although the patient has a history of starting fires, his motivations (e.g., "just to see how long it would take the firefighters to arrive") do not clearly align with the diagnostic criteria for pyromania, which typically involves fire-setting for pleasure or gratification.
- Antisocial Personality Disorder: While the patient's behavior is concerning, antisocial personality disorder cannot be diagnosed until age 18, and only if there is a history of conduct disorder before age 15. This diagnosis is rare in adolescents and would require long-term observation and evaluation.