ABSTRACT
Major Depressive Disorder (MDD, depression) and associated mood syndromes are among the most common psychiatric disorders in specialist and general medical practice. These syndromes span the life cycle and present with varying symptoms. This chapter elucidates recurring characteristics of depression, including those shared with other psychiatric disorders, comorbidity with other conditions, neuropsychological aspects and changes associated with symptomatology. It defines the complex neurochemical picture involving serotonergic, dopaminergic, noradrenergic, glutamatergic and GABAergic systems. The chapter covers the role of the stress-diathesis model, early life trauma and temperament in mediating depression and mood changes. The notion of depression, or melancholia, has numerous permutations throughout written history, both scientific and artistic in nature. There are three main modalities of treatment, which can be used separately or in combination: pharmacotherapy, psychotherapy and brain stimulation. As depression is episodic, with partial to full inter-episodic recovery, physicians must also be aware of strategies to maintain wellness and prevent relapse.
