A patient is agitated, has pressured speech, and reports losing $20,000 on gambling after not sleeping for days. What is the diagnosis and treatment?

The presentation of agitation, pressured speech, significant financial loss due to gambling, and a prolonged period of sleep deprivation aligns with a diagnosis of acute mania. In acute mania, individuals often exhibit heightened energy, decreased need for sleep, racing thoughts, and can engage in impulsive behaviors, such as excessive gambling.

The treatment of acute mania typically involves the use of mood stabilizers, with lithium being one of the first-line options. Lithium is effective in controlling manic symptoms and stabilizing mood. In some cases, antipsychotics may also be utilized, especially if the patient is experiencing severe symptoms or psychotic features.

The other options do not fit the clinical scenario as closely. Major depressive episodes would not typically present with pressured speech or excessive energy; instead, they often feature low mood and anhedonia. Substance use disorders might initially seem relevant, but the symptoms here suggest a primary mood disorder rather than a substance-induced state. Generalized anxiety disorder is characterized by persistent worry and anxiety more than the manic symptoms displayed, making it an unlikely diagnosis in this context. Hence, acute mania, with the associated treatment of mood stabilizers, is the most appropriate diagnosis and management strategy in this case.