Overview of Depression

The term depression derives from the Latin verb deprimere (to press down, to lower) and evokes a sense of oppression, heaviness, or sinking. Today, it has widely entered everyday language, but is often mistakenly used as a synonym for sadness. In the medical field, however, it refers to a genuine psychiatric disorder, often highly disabling, and in its most severe forms may lead to suicide.

Depression manifests as a pathological lowering of mood that impairs the overall functioning of personality, slowing cognitive, motivational, and behavioral processes. It is a psychogenic illness that can affect any age group and represents the most common mood disorder.

In milder cases, diagnosis can be challenging, as the boundary between clinical depression and a normal mood drop in response to life events (such as bereavement) is often subtle. Diagnostic evaluation is strictly within psychiatric competence and is based on the criteria of the DSM (Diagnostic and Statistical Manual of Mental Disorders) published by the American Psychiatric Association.

A distinctive feature of depressive syndromes is the recurrence over time of depressive episodes, which are classified as major depressive episodes and minor depressive episodes. The former occurs in major depressive disorder, dysthymic disorder, and in type I and II bipolar disorders (although it may be absent in type II). The latter is typical of minor depressive disorders and presents with similar symptoms, but with less functional impairment.

Treatment is a specialist matter and is based on a combination of pharmacological therapy and psychotherapy, with structured and targeted psychological programs. In some cases, complementary interventions such as music therapy or pet therapy may be added, involving the therapeutic use of music and the interaction with companion animals, respectively.

Electroshock therapy (electroconvulsive therapy), once widely used, is now reserved for extremely severe cases and is practiced by a limited number of specialists. In the experimental field, new techniques are being developed, such as vagus nerve stimulation, a form of electrical stimulation of the vagus nerve through a small implanted device, similar to a pacemaker, which sends regular impulses with antidepressant purposes.

References
1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders (DSM-5-TR). American Psychiatric Publishing. 2022.
2. Kessler RC et al. The epidemiology of major depressive disorder: results from the National Comorbidity Survey Replication (NCS-R). JAMA. 2003;289(23):3095–3105.
3. Fava GA et al. Prodromal symptoms in mood disorders. Psychiatric Clinics of North America. 2004;27(1):21–33.
4. Insel TR et al. Research domain criteria (RDoC): toward a new classification framework for research on mental disorders. Am J Psychiatry. 2010;167(7):748–751.
5. Cuijpers P et al. Psychological treatment of depression in primary care: a meta-analysis. Br J Gen Pract. 2011;61(582):e738–e746.
6. Rush AJ et al. Acute and longer-term outcomes in depressed outpatients requiring one or several treatment steps: a STAR*D report. Am J Psychiatry. 2006;163(11):1905–1917.
7. Fountoulakis KN et al. ECT in Europe: analysis of the data from the collaborative study of the European Consortium on Electroconvulsive Therapy (ECCE). Eur Arch Psychiatry Clin Neurosci. 2012;262(6):543–552.
8. Nemeroff CB et al. The role of psychotherapeutic agents in the treatment of depression. J Clin Psychiatry. 2003;64(Suppl 1):5–18.
9. George MS et al. Vagus nerve stimulation: a new tool for brain research and therapy. Biol Psychiatry. 2000;47(4):287–295.
10. Maratos AS et al. Music therapy for depression. Cochrane Database Syst Rev. 2008;(1):CD004517.