Major Depressive Disorder (MDD): 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: Neurotransmitters are chemical messengers in the brain that transmit signals between nerve cells. Imbalances in certain neurotransmitters have been associated with depression.