
| Drug | Mechanism of Action | Indications | Contraindications | Advantages | Disadvantages |
| Tricyclic Antidepressants (TCAs) | Inhibit reuptake of norepinephrine and serotonin; also affect cholinergic, histaminergic, and adrenergic receptors. | Major depression, neuropathic pain, anxiety disorders; used in monotherapy or combination (requires close monitoring). | Cardiopathies, glaucoma, prostatic hypertrophy, high suicidal risk. | Powerful antidepressant effect; also effective for somatic symptoms and pain. | Wide and complex side effect profile; risk of cardiac toxicity. |
| Monoamine Oxidase Inhibitors (MAOIs) | Irreversibly or reversibly inhibit monoamine oxidases, increasing synaptic monoamine levels. | Atypical or treatment-resistant depression, hypersomnia, hyperphagia; used in monotherapy or in combination with psychotherapy. | Poor dietary compliance, severe drug interactions (hypertensive crisis with tyramine). | Effective in non-responders to other antidepressants. | Complex management; requires strict diet and close monitoring. |
| Second-Generation Antidepressants | Act selectively on receptors and transporters (SSRIs, SNRIs, NaSSA, NDRI); improved tolerability and safety. | Unipolar depression, dysthymia, anxiety; first-line as monotherapy or combination with psychotherapy. | Drug hypersensitivity, uncontrolled epilepsy, concurrent use with MAOIs. | Good tolerability, low toxicity; strong clinical evidence base. | Delayed onset, possible initial anxiety activation; sexual dysfunction. |
| Antidepressant-Acting Antipsychotics (Neuroleptic) | Modulate dopamine and serotonin (D2/5-HT2A antagonism); some have mood-stabilizing activity. | Depression with agitation, psychotic or resistant features; used only in combination with antidepressants. | Metabolic syndrome, prolonged QT, extrapyramidal risk. | Enhance antidepressant effect; effective for psychotic or mixed symptoms. | Weight gain, sedation, metabolic and neurological risks. |
| Lithium Salts | Modulate intracellular signaling (second messengers) and neuroplasticity; stabilize mood. | Bipolar depression, high suicide risk, antidepressant augmentation; used in combination. | Renal failure, hypothyroidism, dehydration, pregnancy. | Reduces suicide risk; effective in resistant and bipolar forms. | Requires constant monitoring; risk of renal and thyroid toxicity. |