Insomnia CAN lead to depression
When analyzed together, the findings of three separate scientific studies showed that insomnia can indeed contribute to, and deepen, depression. The first analysis involved a large group of Swiss subjects, monitored over the long period of two decades. The second study focused on senior citizens ages 60 and over in a retirement type community. It was found in their case that those with persistent, regular insomnia were 1.8 to 3.5 times as likely to remain depressed as those who slept normally. This was especially true for the elderly study subjects suffering from Major Depressive Disorder, or MDD.
The third study separated patients into two groups and looked at which half improved more, those treated for depression or those treated for insomnia. In the case of these dangerously intertwined symptoms, research found that targeted insomnia treatment was far more effective at reducing the depression than cases where the depression itself was focused on.
Why Is Depression Associated with Insomnia?
As far as why depression might be abetted by insomnia, the scientists analyzing the combined findings of the three studies had a number of theories. These include: lying awake at night allows people to have more time to ponder those thoughts that are depressing them; a lack of sleep can directly impact neurobehavioral functioning; and insomnia can also contribute to unhealthy changes in normal human diurnal (day-night) mood biorhythms.