When diagnosing a mental illness (https://www.psychiatry.org/patients-families/warning-signs-of-mental-illness), doctors tend to look at how a person is feeling, a person’s cognitive functioning, and their behaviors. The affect of an individual can indicate a person’s emotions on a deep level. However, if it is not self-reported, it is communicated in terms of behaviors: “My friend/family member is acting cold and withdrawn.” Likewise, a person’s cognitive functioning requires a description of doing: “He couldn’t even remember his own phone number.” These behaviors coalesce into a rounded form of information that can lead to a formal psychiatric diagnosis.
Behaviors, when performed over and over, become habits. Habits such as sleeping too much are linked to depression (http://www.webmd.com/sleep-disorders/guide/physical-side-effects-oversleeping#1/). Habits such as sleeping too less are linked to psychosis (http://serendip.brynmawr.edu/exchange/serendipupdate/effects-sleep-deprivation-brain-and-behavior/). And of course, habits such as substance abuse become their own diagnosis (https://www.centeronaddiction.org/).
These habits are all made possible by the schedule a person keeps because of their position in life. Someone who has to work a full-time job and then go to school every night might have a tougher time getting the sleep they need. Someone who works from home may be getting too much sleep. These habits are made possible partially by a person’s employment. Of course, we all have the position in life to change our own behavior. Author Charles Duhigg writes about how to change a behavior given the science of habit loops in his book “How Habits Work” (http://charlesduhigg.com/how-habits-work/).
So if you are feeling depressed, consider scheduling some time for a little exercise. If you are having weird thoughts about your neighbor, try getting a good night’s sleep. And if you’re having trouble with an addiction, be it coffee or heroin, try replacing the behavior with something more healthy but still reward-rich. And of course, have a good life the entire way!