From the Guidelines
The diagnosis of major depression requires the presence of at least five symptoms during the same 2-week period, with at least one symptom being either depressed mood or loss of interest/pleasure (anhedonia). The specific symptoms include:
- depressed mood most of the day nearly every day;
- markedly diminished interest or pleasure in almost all activities;
- significant weight loss or gain (more than 5% of body weight in a month) or changes in appetite;
- insomnia or hypersomnia nearly every day;
- psychomotor agitation or retardation observable by others;
- fatigue or loss of energy;
- feelings of worthlessness or excessive guilt;
- diminished ability to think or concentrate;
- and recurrent thoughts of death or suicide. These symptoms must cause clinically significant distress or impairment in functioning, cannot be attributable to a medical condition or substance, and must not be better explained by another psychiatric disorder like schizoaffective disorder 1.
When evaluating patients, it's essential to conduct a thorough assessment including medical history, medication review, and screening for other psychiatric conditions that may mimic or coexist with depression. The severity of depression can be classified as mild, moderate, or severe based on symptom count, intensity, and functional impairment 1. This classification helps guide treatment decisions regarding psychotherapy and medication management.
It's also important to note that major depressive disorder is a clinical syndrome lasting at least 2 weeks during which the patient experiences either depressed mood or anhedonia plus at least 5 of the following symptoms, as defined by the American Psychiatric Association 1.
In terms of diagnosis criteria, the American Psychiatric Association defines major depressive disorder as depressed mood or loss of pleasure or interest along with other symptoms, including significant change in weight or appetite, insomnia or hypersomnia, psychomotor agitation or retardation nearly every day, fatigue or loss of energy, feelings of worthlessness or excessive or inappropriate guilt, indecisiveness or decreased ability to concentrate, and recurrent thoughts of death or suicide, that last for at least 2 weeks and affect normal functioning 1.
Overall, the diagnosis of major depression requires a comprehensive evaluation of the patient's symptoms, medical history, and functional impairment, and should be guided by the most recent and highest-quality evidence available 1.
From the Research
Diagnosis Criteria for Major Depression
The diagnosis criteria for major depression are defined as five or more of the following symptoms in the past 2 weeks, during which at least one is depressed mood or loss of interest or pleasure 2. The symptoms include:
- Depressed mood
- Diminished interest or pleasure in activities
- Significant weight loss or gain, or decreased or increased appetite
- Insomnia or hypersomnia
- Psychomotor agitation or retardation
- Fatigue or loss of energy
- Feelings of worthlessness or excessive or inappropriate guilt
- Poor concentration or indecisiveness
- Recurrent thoughts of death or suicidal ideation, plan, or attempt
Screening and Management
Screening for major depressive disorder (MDD) is recommended in the general adult population when resources are available for diagnosis, management, and follow-up 2. Several screening tools are available, including the Patient Health Questionnaire-9 (PHQ-9) and Beck Depression Inventory for Primary Care (BDI-PC). Management of MDD depends on its severity and may include psychotherapy, pharmacotherapy, or both 2.
Treatment Options
The drugs most commonly used to treat MDD are selective serotonin reuptake inhibitors (SSRIs) 2, 3, 4, 5, 6. The optimal dose of SSRIs, venlafaxine, and mirtazapine in major depression has been studied, and the results suggest that the lower range of the licensed dose achieves the optimal balance between efficacy, tolerability, and acceptability in the acute treatment of major depression 3.
Efficacy and Tolerability of SSRIs
The efficacy and tolerability of SSRIs have been assessed in numerous clinical controlled trials, and meta-analyses have confirmed that SSRIs are effective in improving the symptoms of depression 5, 6. However, there is no scientific evidence to suggest that any one SSRI is more effective than another, but not all patients respond to the same agent 5. A recent umbrella review found that escitalopram was more effective than other defined SSRIs in terms of response rate, remission rate, and withdrawal rate 6.