Depression is a mental health disorder characterized by a sad mood or loss of interest in daily activities interfering in the lifestyle of those who suffer from it.

Some of the possible causes of depression include a combination of social, biological and psychological factors. These also may cause changes in brain function such as altered activity or certain neural circuits, research suggests.

This behavior is frequently characterized by sadness and loss of interest, behaviors that may lead to a range of symptoms that include changes in sleep, appetite, concentration and even thoughts of suicide.

Diagnosis

The diagnosis of depression is exclusively clinical, through an interview (therapist-patient). There are no complementary tests, such as blood tests or imaging tests (scan or MRI), that can confirm the diagnosis of depression. Nor are there, to date, genetic tests that confirm the diagnosis of depression.
In short, the only way to make a diagnosis of depression is through a clinical interview, preferably carried out by a doctor specializing in psychiatry or by a psychologist specializing in clinical psychology. The clinical interview involves making a series of questions and observations on the patient that, taken together and considering their personal and family history, lead to a clinical diagnosis.