As per DSM V criteria depressed mood or a loss of interest or pleasure in daily activities for more than two weeks. Mood represents a change from the person's baseline. Five or more of the following symptoms have been present during the same 2-week period and represent a change from previous functioning; at least one of the symptoms is either 1 depressed mood or 2 loss of interest or pleasure.
Depression is commonly phrased as neurochemical imbalance. Neurotransmitters that mediate depression are Serotonin, GABA, Dopamine and norepinephrine. Serotonin is hypothesized to regulate other neurotransmitter systems; decreased serotonin activity may allow these systems to act in unusual and erratic ways.
Very low mood, poor concentration, inability to experience pleasure, feeling of worthless, helpless, guilt, self hatred, weight loss or gain, hopeless, loss of interest, withdrawal, reduced sex drive, poor sleep, or over sleep, fatigue, headache, digestive issues, agitated or lethargic. Some may experience memory loss, slowing of movements, suicidal thoughts or plan, harming others.
5 subtypes are there.
Psychiatrist or a psychologist will come to a diagnosis based on the mental health examination. That may include the use of rating scale such as Hamilton Rating Scale for depression or the Beck Depression Inventory or the Suicide Behaviors questionnaire-Revised. Clinician comes to the diagnosis of depression after thorough examination and symptoms of the person satisfy the DSM-criteria or ICD. Before finalizing the diagnosis clinician rules out other medical conditions that mimic depression that are hypothyroidism, basic electrolyte disturbance, metabolic disturbance, and other systemic conditions. In males hypogonadism has to be ruled out before diagnosing depression.