Tobacco (nicotine) use disorder

Tobacco use is the leading cause of preventable death in the United States, and every smoker should be asked about use at every visit and offered combined behavioral counseling plus pharmacotherapy, since neither alone matches the quit rate of both together. Varenicline is the most effective single agent, combination nicotine replacement therapy (long-acting patch plus a short-acting form) is equally first-line, and bupropion is an alternative, all started before a set quit date and continued for a 7- to 12-week course.

Lung cancer is the leading cause of cancer death worldwide, split into non-small cell lung cancer (NSCLC, 80% of cases: adenocarcinoma, squamous cell, large cell) and small cell lung cancer (SCLC, 10-15%), both driven overwhelmingly by cigarette smoking. Diagnosis requires tissue histopathology, staging drives treatment (TNM staging for NSCLC, limited versus extensive stage for SCLC), and management ranges from lobectomy in early-stage disease through concurrent chemoradiation and consolidation immunotherapy in locally advanced disease to targeted tyrosine kinase inhibitors, immune checkpoint inhibitors, or platinum-based chemotherapy in metastatic disease.

Chronic obstructive pulmonary disease is a persistent, usually progressive airflow obstruction driven mainly by cigarette smoke, confirmed by a postbronchodilator FEV1/forced vital capacity (FVC) ratio below 0.70 and staged by GOLD spirometric grade plus symptom/exacerbation group. Maintenance management is a stepwise ladder of smoking cessation, long-acting bronchodilators, add-on inhaled glucocorticoid, roflumilast, or azithromycin for frequent exacerbators, long-term oxygen for resting hypoxemia, and vaccination, with acute exacerbations managed as a separate protocol.

Alcohol use disorder is a chronic pattern of drinking meeting 2 or more of 11 DSM-5 criteria within a 1-year period, screened with the CAGE or AUDIT-C and confirmed by history. First-line management combines a brief behavioral intervention and cognitive behavioral therapy with naltrexone or acamprosate, reserving disulfiram for highly motivated patients who can maintain abstinence.

Opioid use disorder is a maladaptive pattern of opioid use causing significant impairment or distress, diagnosed by meeting 2 or more of 11 substance use disorder criteria within a 12-month period. First-line treatment is medication for opioid use disorder: buprenorphine or methadone maintenance for ongoing agonist therapy, or naltrexone once the patient is confirmed opioid-free, paired with psychosocial care and take-home naloxone.

Stimulant use disorder is a pattern of amphetamine-type stimulant use, covering methamphetamine, misused prescription amphetamines, and MDMA, that meets 2 or more of 11 substance use disorder criteria within 12 months. Intoxication produces a sympathomimetic toxidrome with hyperthermia and agitation; management starts with a benzodiazepine and active cooling, since no pharmacotherapy is approved for the use disorder itself and contingency management is the named behavioral treatment.

Generalized anxiety disorder is excessive, hard-to-control worry about multiple life domains occurring more days than not for at least 6 months, with at least 3 of 6 associated physical symptoms and functional impairment. Screen with the GAD-7 after excluding hyperthyroidism and substance use, then treat first-line with cognitive behavioral therapy and/or an SSRI or SNRI such as escitalopram or venlafaxine extended-release, reserving benzodiazepines for short-term severe symptom control only.

Major depressive disorder is a mood disorder defined by 5 or more of 9 major depressive episode symptoms, including depressed mood or anhedonia, present nearly every day for at least 2 weeks and causing significant functional impairment. Diagnosis is clinical, screened with the Patient Health Questionnaire. First-line treatment is cognitive behavioral therapy, a selective serotonin reuptake inhibitor (SSRI) such as sertraline, or both, escalating to augmentation, esketamine, or electroconvulsive therapy for refractory or acutely suicidal presentations.

Panic disorder is an anxiety disorder defined by recurrent, unexpected panic attacks, discrete surges of fear that peak within 10 minutes with 4 or more characteristic symptoms, followed by at least 1 month of persistent worry about further attacks, worry about their consequences, or a maladaptive behavior change. Medical mimics such as acute coronary syndrome, pulmonary embolism, arrhythmia, hyperthyroidism, pheochromocytoma, and hypoglycemia must be excluded first. First-line treatment is a selective serotonin reuptake inhibitor such as sertraline, started low and titrated slowly, combined with cognitive behavioral therapy; benzodiazepines are reserved for short-term acute control.