Start of treatment: time of action, adherence, and clinical response

The treatment of depression, especially in its moderate and severe forms, involves understanding the natural clinical course of the disease and the expected response to therapeutic interventions.

The course is usually divided into phases: acute phase, remission phase, and recovery phase. The acute phase corresponds to the period of symptom onset and its duration can vary. A response to treatment is considered to occur when a 50% improvement in initial symptoms is achieved.

Remission involves the almost complete disappearance of symptoms, and recovery occurs when, in addition to being asymptomatic, the patient has regained their previous functionality.

A key point is to distinguish between relapse and recurrence: relapse is the reappearance of symptoms before recovery has been achieved, while recurrence occurs after a prolonged period without symptoms. This distinction is crucial for adjusting clinical follow-up and therapeutic decisions.

Treatment duration and adherence

Antidepressants, especially selective serotonin reuptake inhibitors (SSRIs), are commonly used as first-line pharmacological treatment. However, their effect is not immediate.

The onset of action is typically expected between the second and fourth week of treatment, although some symptoms, such as sleep or appetite disturbances, may begin to improve earlier.

Adherence to treatment is a common difficulty. Many patients discontinue medication before completing the necessary therapeutic cycle, either because of impatience with the lack of immediate effect, adverse effects, or cultural stigmas associated with the use of psychotropic drugs.

Added to this is the frequent use of subtherapeutic doses, which prevents the effectiveness of treatment from being properly assessed and can lead to a misdiagnosis of refractory depression.

Clinical response, resistant depression, and augmentation strategies

It is estimated that up to one-third of patients with depression do not achieve complete remission after two well-administered treatments. This condition is called resistant or refractory depression. In these cases, it is essential to confirm that previous treatments have been administered at the appropriate doses and times before assuming refractoriness.

In the absence of a clinical response, augmentation strategies may be used, which involve combining the antidepressant with another medication to enhance its effect.

Among the most widely supported alternatives are certain atypical antipsychotics (such as aripiprazole, quetiapine, or olanzapine), lithium carbonate, and in some cases thyroid hormone. These combinations should be carefully evaluated for their efficacy and tolerability profile.