What is the most appropriate treatment for a patient presenting with manic symptoms including grandiosity and impulsive spending?

The most appropriate treatment for a patient presenting with manic symptoms, such as grandiosity and impulsive spending, is inpatient olanzapine therapy. This is because olanzapine is an atypical antipsychotic that effectively manages acute manic episodes, particularly in bipolar disorder. It's important to recognize that mania can lead to severe disruption in a person's life, and inpatient care allows for close monitoring and immediate intervention if necessary.

Inpatient treatment is particularly beneficial when symptoms are severe or when the risk of harm to self or others is significant, as tends to be the case with manic episodes. Furthermore, the rapid onset of olanzapine makes it suitable for controlling symptoms quickly and helping stabilize the patient.

Cognitive behavioral therapy, while useful in long-term management, is not the primary intervention for acute mania as there may be insufficient stability for effective cognitive processing. Electroconvulsive therapy is typically reserved for severe or treatment-resistant cases and is not first-line in managing acute mania. Antidepressants may exacerbate manic symptoms and are generally avoided in the treatment of a manic episode. Hence, inpatient olanzapine therapy remains the most effective and appropriate choice in this situation.