Mood Disorders

Antidepressants encompass several classes of medications and are used to treat individuals with depression, anxiety, and other psychiatric conditions, as well as to manage chronic pain and menopausal symptoms. Bupropion is an atypical antidepressant that acts by increasing neurotransmitter levels and alleviates the symptoms of depression. Brexanolone is a neurosteroid mainly used for the management of postpartum depression.

Monoamine oxidase inhibitors are a class of antidepressants that inhibit the activity of monoamine oxidase (MAO), thereby increasing the amount of monoamine neurotransmitters (particularly serotonin, norepinephrine, and dopamine). The increase of these neurotransmitters can help in alleviating the symptoms of depression. Selective inhibitors of MAO type B can also be used for the treatment of Parkinson disease. Other uses include for bulimia nervosa and panic disorder. The major adverse effects include serotonin syndrome and hypertensive crisis. Special care should be taken to avoid other serotonergic medications and tyramine-containing foods.

Major depressive disorder (MDD), commonly called depression, is a unipolar mood disorder characterized by persistent low mood and loss of interest in association with somatic symptoms for a duration of ≥ 2 weeks. Major depressive disorder has the highest lifetime prevalence among all psychiatric disorders. Biologic, psychosocial, and genetic factors contribute to depression. Treatment methods include pharmacotherapy, psychotherapy, and neuromodulation therapies such as electroconvulsive therapy (ECT). The leading cause of death associated with MDD is suicide, which is more common in the elderly population.

Bipolar disorder is a highly recurrent psychiatric illness characterized by periods of manic/hypomanic features (distractibility, impulsivity, increased activity, decreased sleep, talkativeness, grandiosity, flight of ideas) with or without depressive symptoms. The etiology is unknown but is believed to be a complex interplay of different factors: genetic, neurobiologic, and environmental. Diagnosis is clinical, with the help of screening tools to determine mood and depression symptoms. Underlying substance use or medical conditions need to be ruled out with laboratory and imaging tests if indicated. Treatment of bipolar disorder varies based on the presenting features but usually involves pharmacotherapy with lithium, valproic acid, and/or antipsychotic medications. Other methods include psychotherapy and somatic therapies. Acute severe mania is a medical emergency and generally requires hospitalization. Maintenance therapy is typically necessary to reduce symptoms, prevent new mood episodes, decrease risk of suicide, and improve overall psychosocial functioning.

Antidepressants encompass several drug classes and are used to treat individuals with depression, anxiety, and psychiatric conditions, as well as those with chronic pain and symptoms of menopause. Antidepressants include selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), and many other drugs in a class of their own. Antidepressants are indicated as the 1st-line treatment for anxiety disorders and major depressive disorder (MDD) and are contraindicated in cases of current or recent use of monoamine oxidase inhibitors. Therapeutic response to antidepressants takes 2–4 weeks and complete benefit is not seen until up to 8 weeks, which is attributed to downstream cellular responses necessary for eliciting a physiologic response. In general, serotonin-affecting antidepressants are well tolerated, but caution must be taken while prescribing them in combination with other drugs that inhibit or induce the same hepatic cytochrome P450 enzymes to prevent increased levels of both drugs. An overdose can be life-threatening. It is important to recognize the signs and symptoms of SSRI/SNRI overdose to enable prompt treatment in an emergency setting.