Patients suffering from endogenous depression may conceal psychiatric symptoms and may address a general physician instead of a psychiatrist with somatic complaints [1] [2] [3] like headaches, muscle aches, numbness or abdominal distress, for fear of being diagnosed with a mental illness, that would cast a stigma on them. They may also genuinely believe physical symptoms are the cause of their low mood and dysphoria, not the other way around [4] [5] [6]. Aside from the symptoms enumerated above, affected individuals exhibit anhedonia, irritability, persistent sadness or sense of worthlessness, asthenia, isolation, eating disorders leading to weight changes, lack of motivation, insomnia, and difficulty in concentrating and memorizing new information. Disinterest in sexual activities is also noticed. Patients may find it difficult to impose their opinion, express strong feelings and cope with casual activities. They are often insecure and feel helpless. Perceived quality of life decreases, for the individual and his or her caregivers. Agitation or lethargy or swings between these two states are also frequently encountered. In more advanced stages, hallucinations and suicidal ideation arise, in parallel with social isolation. Patients may also provoke self-injury. Depression may also be a symptom of other psychiatric diseases, such as schizophrenia. When associated with psychosis, depression may also signalize bipolar affective disorder, substance abuse or organic brain syndrome. The prognosis of associated illnesses is two times worse in a depressed patient.

Symptoms may vary among age groups. Even preschool children may be affected [7] [8]. Children of all ages more often present with irritability or decline in school grades or even marasmus [9], whereas elders more often have confusion and somatic signs as dominant findings.

There is no specific physical trait that helps diagnose endogenous depression aside from the fact that the physician may notice decreased hygiene, decreased movement and reactivity or agitation. However, infection, hypothyroidism, Cushing's syndrome, Addison's disease, hypopituitarism and a number of tumors and neurologic organic disorders may cause endogenous depression and must be eliminated by physical examination and laboratory workup. Blood tests should include a complete blood cell count, blood alcohol and vitamin B12 levels, toxicology screening, thyroid-stimulating hormone levels, liver, and kidney function tests. Dexamethasone suppression test and cosyntropin stimulation test can overrule Cushing's syndrome and Addison's disease.

When a neurologic substrate is suspected based on the presence of neurologic deficits, imaging modalities such as computer tomography, magnetic resonance imaging, positron emission tomography and single-photon emission computed tomography scanning may prove useful; the latter demonstrating regional perfusion deficits in affected patients [10] [11].

Several depression tests exist. Some are based on patient's understanding of depression [12], some describe and inquire about symptoms [13]. Depression scales, such as Zung self-rating depression scale, geriatric depression scale, patient health questionnaire, Beck depression inventory, center for epidemiologic studies-depression scale or Hamilton depression rating scale should be used. They are self-applied or the last one should be carried out in a clinical setting.

Treatment for endogenous depression typically involves a combination of medication and psychotherapy. Antidepressant medications, such as selective serotonin reuptake inhibitors (SSRIs) or tricyclic antidepressants, are commonly prescribed to help balance neurotransmitters in the brain. Psychotherapy, particularly cognitive-behavioral therapy (CBT), can be effective in helping patients develop coping strategies and change negative thought patterns. In some cases, electroconvulsive therapy (ECT) may be considered for severe or treatment-resistant depression.

The prognosis for individuals with endogenous depression varies depending on the severity of the condition and the effectiveness of treatment. With appropriate intervention, many patients experience significant improvement in their symptoms and can lead fulfilling lives. However, some individuals may experience recurrent episodes of depression, necessitating ongoing management and support. Early diagnosis and treatment are key factors in improving outcomes.

The exact cause of endogenous depression is not fully understood, but it is believed to result from a combination of genetic, biological, and environmental factors. A family history of depression or other mood disorders can increase the risk of developing endogenous depression. Neurochemical imbalances, particularly involving neurotransmitters like serotonin and norepinephrine, are also thought to play a role. Stressful life events may exacerbate symptoms, but they are not considered the primary cause.

Endogenous depression affects individuals across all age groups, but it is most commonly diagnosed in adults. It is estimated that major depressive disorder, including endogenous depression, affects approximately 5-10% of the population at some point in their lives. Women are more likely to be diagnosed with depression than men, which may be due to a combination of biological, hormonal, and social factors.

The pathophysiology of endogenous depression involves complex interactions between genetic predispositions and neurobiological processes. Dysregulation of neurotransmitters, such as serotonin, norepinephrine, and dopamine, is believed to contribute to the development of depressive symptoms. Structural and functional changes in brain regions associated with mood regulation, such as the prefrontal cortex and hippocampus, have also been observed in individuals with depression.

While it may not be possible to prevent endogenous depression entirely, certain strategies can help reduce the risk or mitigate the severity of symptoms. Maintaining a healthy lifestyle, including regular exercise, a balanced diet, and adequate sleep, can support overall mental health. Stress management techniques, such as mindfulness and relaxation exercises, may also be beneficial. Early intervention and treatment of depressive symptoms can prevent progression to more severe forms of depression.

Endogenous depression is a form of major depressive disorder characterized by symptoms that arise from internal factors rather than external events. It involves a complex interplay of genetic, biological, and environmental influences. Diagnosis requires a thorough evaluation, and treatment typically includes medication and psychotherapy. While the prognosis can vary, early intervention and comprehensive management can lead to significant improvement in symptoms.

If you or someone you know is experiencing symptoms of depression, it is important to seek help from a healthcare professional. Endogenous depression is a treatable condition, and with the right support, individuals can manage their symptoms and improve their quality of life. Treatment options are available, and healthcare providers can work with patients to develop a personalized plan that addresses their specific needs and circumstances.

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