A 72-year-old man presents to a rehabilitation facility for a routine follow-up, 3 weeks after an ischemic stroke affecting his left parietal lobe. His family reports he has become increasingly withdrawn, exhibiting significant anhedonia, tearfulness, reduced energy, and difficulty falling asleep. He also mentions a marked decrease in his interest in previously enjoyed activities and a significant weight loss due to poor appetite over the past month. Physical examination reveals a thin man with a flat affect. His blood pressure is 128/78 mmHg, pulse 68/min, respiratory rate 14/min, and temperature 36.7 °C. Neurological exam shows residual right-sided weakness and mild expressive aphasia. Given his clinical presentation and recent medical history, what is the most likely psychiatric diagnosis and the immediate pharmacologic management strategy?

A 55-year-old recently separated woman presents to the general medical clinic expressing ongoing feelings of profound sadness and anhedonia over the past two months. She reports significant difficulty falling and staying asleep, resulting in chronic fatigue, and notes a decreased appetite leading to a modest weight loss of 3 kg. Her medical history includes well-controlled hypertension and a seizure disorder that has been stable on medication for several years. She is open to pharmacologic intervention for her depression but expresses significant apprehension regarding potential sexual side effects, citing past negative experiences. Physical examination reveals a blood pressure of 130/80 mmHg and a heart rate of 72 beats per minute. Her neurological exam is non-focal, and no signs of acute distress are observed. Basic laboratory tests were performed. Given this patient's presentation and medical history, what is the most appropriate initial management strategy, and what specific pharmacotherapy should be prioritized?

A 32-year-old woman presents to a primary care physician's office complaining of a persistent low mood for the past six weeks. She reports anhedonia, significant fatigue, difficulty concentrating at work, and initial insomnia. She denies any prior psychiatric history. Her current situation stems from a recent job loss, though she states her mood has progressively worsened beyond normal sadness. She was started on escitalopram 10 mg daily three weeks ago by her general practitioner. She reports some improvement in her sleep architecture and appetite, but describes her mood as "still very up and down, not fixed." She is concerned about the medication's effectiveness and is considering stopping it. Considering her presentation and current medication, what are the most pertinent differential diagnoses and the optimal next step in her pharmacological management?

A 72-year-old woman, with a known history of chronic hypertension managed with hydrochlorothiazide and recurrent major depressive disorder, presents to her general outpatient clinic for a follow-up visit. Two weeks prior, her primary care physician initiated escitalopram therapy due to a significant recurrence of depressed mood, profound anhedonia, sleep disturbances, and marked difficulty with concentration and executive function. During this visit, she reports no discernible improvement in her depressive symptoms. Furthermore, her family expresses increasing concern regarding new-onset symptoms over the past two days, including a significant reduction in appetite, persistent nausea, overwhelming fatigue, and episodes of disorientation. She denies any recent episodes of emesis, diarrhea, or fever. On physical examination, her vital signs are stable, but she exhibits mild generalized weakness and appears mildly confused when asked about the date. Her mucous membranes are moist, and there is no peripheral edema. Given these developments, what is the most appropriate immediate management step and what potential metabolic complication should be urgently investigated?

A 34-year-old male architect, with a history of recurrent major depressive disorder, presents to his primary care physician's office. He reports a 3-day history of escalating malaise, lightheadedness, and a pervasive sense of "brain zaps" and internal trembling that began shortly after returning from a demanding international project where he inadvertently missed several doses of his prescribed escitalopram. He states he has been on a stable dose for the past 9 months and generally felt well controlled prior to this trip. He attributes his current symptoms to either a severe viral illness or a sudden exacerbation of his underlying mood disorder, leading him to completely discontinue the medication upon his return, believing it was no longer effective. He denies any fever or chills but admits to significant difficulty concentrating and fragmented sleep. His partner noticed he has been unusually irritable and tearful. Physical examination reveals vital signs within normal limits. Neurological examination reveals no focal deficits; cranial nerves intact, motor strength 5/5 bilaterally, sensation intact, reflexes 2+ and symmetric. No nystagmus or ataxia. Deep tendon reflexes are symmetrical and appropriate. General appearance is mildly anxious but cooperative. Considering his presentation, what is the most likely diagnosis and the immediate therapeutic intervention?

A 45-year-old male presents to a general internal medicine clinic reporting a persistent low mood and a significant decline in his usual activities over the past month. He describes experiencing pervasive anhedonia, characterized by a profound lack of interest in once-cherished hobbies like gardening and reading. His sleep has been fragmented, with early morning awakenings and difficulty returning to sleep, despite feeling unrested throughout the day. He reports a noticeable decrease in appetite, leading to unintentional weight loss, and frequent episodes of tearfulness. Concentration has become a struggle, affecting his work productivity. He denies any history of substance use disorders but mentions a family history of mood disorders, specifically his mother having experienced similar episodes in her late 40s. On physical examination, his vital signs are stable (BP 120/78 mmHg, HR 72 bpm, RR 16/min, Temp 36.8°C). His affect is constricted, and he appears fatigued. Neurological examination is non-focal. Given his presentation, what is the most likely diagnosis and the most appropriate initial pharmacological approach?

A 50-year-old man presents to an outpatient psychiatric clinic for a follow-up visit regarding his depression. He was diagnosed with major depressive disorder 6 weeks ago and initiated on sertraline 50 mg daily. He reports modest improvement in his depressive symptoms, particularly in mood and energy levels, but is significantly distressed by new-onset sexual dysfunction, specifically decreased libido and difficulty achieving and maintaining erections and ejaculation. He is in a stable, long-term relationship and denies any prior history of sexual dysfunction. His medical history includes well-controlled hypertension and type 2 diabetes mellitus, managed with lisinopril and metformin, respectively. Vital signs are stable, and a general physical examination reveals no acute abnormalities. Considering the patient's presentation, what is the most appropriate initial diagnostic consideration and the subsequent management strategy?

A 33-year-old woman presents to a community health clinic complaining of persistent low mood, anergia, and difficulty concentrating for the past several weeks. She describes her sleep as disrupted and reports a reduced interest in previously enjoyed activities. During the history, she reveals that she started taking St. John's Wort approximately two months ago, purchased online, in an attempt to alleviate her symptoms, but has noted only minimal improvement. She now requests a prescription for an antidepressant, specifically mentioning fluoxetine, as she has heard it is effective. She expresses a desire to continue the St. John's Wort alongside any prescribed medication, believing "more is better" for her mental well-being, and is particularly concerned about medication dependency. On examination, her vital signs are stable: temperature 37.0 °C, heart rate 72 bpm, blood pressure 120/78 mmHg, respiratory rate 16 breaths/min. Her physical exam is otherwise unremarkable. Laboratory findings include:

A 42-year-old man presents to an outpatient clinic with his sister, who reports he has been increasingly agitated, confused, and sweating excessively over the past few hours. His medical history includes well-controlled major depressive disorder with fluoxetine 20 mg daily. His sister mentions he recently developed a cold and has been taking an over-the-counter cough and cold medication containing dextromethorphan. On examination, he is disoriented and restless. His blood pressure is 155/95 mm Hg, pulse is 135 beats per minute, respiratory rate is 22 breaths per minute, and temperature is 39.2°C. His skin is flushed and diaphoretic, and his pupils are symmetrically dilated and reactive. Neurological examination reveals generalized hyperreflexia, spontaneous clonus in both ankles, and a coarse tremor of the upper extremities. He has no nuchal rigidity. What is the most likely diagnosis and the immediate next step in management?

A 35-year-old woman, who has been effectively managed for major depressive disorder for the past two years, presents to her primary care provider with increasing distress over sexual dysfunction, specifically diminished libido and anorgasmia. She reports compliance with her current antidepressant regimen and notes significant improvement in her mood. Physical examination reveals a well-appearing female, normotensive with a blood pressure of 120/78 mmHg, heart rate 72 beats/min, respiratory rate 16 breaths/min, and temperature 36.8 °C. Her neurological exam is non-focal, and abdominal examination is soft, non-tender, and non-distended with normal bowel sounds. Genitourinary exam is deferred given the nature of the visit. Given her clinical picture, what is the most appropriate pharmacological management strategy, and what are the key non-pharmacological considerations for her ongoing care?

A 35-year-old man presents to his general practitioner reporting a persistent low mood over the past two months. He describes profound fatigue, a pervasive sense of apathy, and a significant loss of interest in hobbies he once enjoyed, including his weekly golf game. His wife has noticed he spends most evenings isolated, staring blankly at the television. He reports difficulty falling asleep and early morning awakenings, often feeling unrefreshing despite spending 8 hours in bed. He has experienced an unintentional weight gain of 3 kg, attributing it to comfort eating. His concentration at work has declined, making it challenging to complete routine tasks. He denies suicidal ideation or psychotic symptoms. Physical examination reveals a man who appears tired but well-nourished. His temperature is 36.80C, blood pressure is 120/78 mmHg, pulse is 65/min, and respirations are 14/min. Oxygen saturation is 99% on room air. Based on these findings and preliminary investigations, what is the most likely diagnosis and the most appropriate initial management strategy?

A 17-year-old female is brought to her family physician by her guardian for notable changes in behavior. Her guardian explains that they relocated to a new town approximately 4 months ago, which necessitated a change in schools. Since enrolling in the new institution, she has exhibited a significant shift in her demeanor. She now spends the vast majority of her time isolated in her bedroom, often lying in bed watching streaming services with the door closed. When she does emerge, she is frequently irritable and prone to arguments. She has stopped attending her weekly volleyball practices, citing overwhelming fatigue and a preference for resting. Last week, her mathematics instructor contacted the guardian, expressing concern that the student frequently appears drowsy during class and is at risk of academic failure. During a private conversation, the patient expressed, "Sometimes, I just wish I wasn't here," but clarified that she has no specific plans or immediate intent to act on these thoughts. She is initiated on a low-dose selective serotonin reuptake inhibitor, fluoxetine, and scheduled for a follow-up. At her 1-week follow-up appointment in the outpatient clinic, her vital signs are stable (BP 110/70 mmHg, HR 72 bpm, RR 16/min, Temp 36.8°C), and physical examination is unremarkable aside from a slightly disheveled appearance. Given these findings, what is the most appropriate immediate management strategy and what critical potential complication must be closely monitored?

A 40-year-old male presents to a community mental health center, referred by his primary care provider due to concerns raised during a routine check-up. His apartment manager had recently reported unsanitary conditions and excessive clutter that was impeding access for maintenance. The patient reluctantly admits to accumulating various items, including old electronics, newspapers spanning decades, and expired food packaging, stating he might "need them someday" or that "it feels wrong to throw them away." This accumulation has resulted in his living space being severely compromised, with only narrow pathways between stacks of belongings, making his kitchen and bathroom almost inaccessible. He avoids inviting friends over and has been sleeping on a sofa in his living room for the past two years, as his bedroom is entirely filled with items. He experiences significant distress when attempts are made to discard any of his possessions, often leading to severe anxiety and agitation, although he generally views his collecting as a rational behavior. Despite the challenges, he reports no other significant mood disturbances or recurrent intrusive thoughts or rituals beyond the acquisition and retention of items. Physical examination reveals an unkempt appearance but no acute distress. Considering his presentation, what is the most likely psychiatric diagnosis, and what is the most appropriate initial combined therapeutic approach for this condition?

A 48-year-old woman presents to her general practitioner's office, expressing a pervasive sense of fatigue and disinterest in activities she once enjoyed, which has persisted for the past four months. She mentions a significant decline in her overall energy levels and an inability to concentrate at work, leading to concerns about her professional performance. She tearfully describes feeling overwhelmed by guilt, believing she is failing her family, particularly her partner, as their previously active lifestyle of evening walks has ceased due to her profound lack of motivation. She reports difficulty initiating sleep and frequent early morning awakenings, often accompanied by a racing heart, despite feeling utterly exhausted throughout the day. She has also noticed changes in her gastrointestinal habits, experiencing intermittent nausea and decreased appetite. Her medical history includes well-controlled essential hypertension and dyslipidemia. She also has a history of mild, well-managed irritable bowel syndrome. Her temperature is 37.0°C, blood pressure is 125/78 mmHg, pulse is 72/min, respirations are 16/min, and oxygen saturation is 99% on room air. Physical examination reveals a woman who appears fatigued but is cooperative. Her speech is soft, and her affect is constricted and sad. Her neurological exam is within normal limits. Considering her clinical presentation and medical history, what is the most likely diagnosis and the optimal initial pharmacologic management strategy?