The onset of clinical depression refers to the beginning or initial appearance of symptoms associated with a depressive disorder. It marks the transition from normal mood fluctuations to persistent feelings of sadness, hopelessness, and other characteristic symptoms.
Major Depressive Disorder is a specific diagnosis characterized by persistent depressed mood and loss of interest or pleasure in daily activities.
Diathesis-Stress Model: The diathesis-stress model proposes that mental disorders like depression develop due to both genetic predisposition (diathesis) and exposure to significant environmental stressors.
Neurotransmitters are chemical messengers in the brain that transmit signals between nerve cells. Imbalances in certain neurotransmitters have been associated with depression.