<human>:  What causes someone to develop depression?
<bot>: The exact cause of depression is not yet fully understood, but a number of factors are thought to be involved, including biological, psychological, and environmental factors. Biological factors such as genetics and underlying brain chemistry can contribute to an increased likelihood of developing depression. Psychological factors such as stress, unresolved childhood trauma, and other forms of life transitions or crisis can also lead to depression. Environmental factors such as poverty, poor living and working conditions, and a lack of community or social support can increase the risk of developing depression. Other potential contributors to depression can include certain medications, physical illnesses, personality, and lifestyle habits.