Thanks Cole for arinegeg that happiness and sadness are different constructs and so are mental well-being and mental illness.You have characterized happiness /ennui spectrum in terms of gains and sadness/irritability spectrum in terms of losses; and here again I concur.However, you state that loss and gains are both apart of life and behaviors directed at both of them are adaptive and only pathological behavior should be of concern.Now consider the fact that a realized or potential loss is characterized by stress. Pathological losses would be characterized by pathological stress which would in my opinion lead to illness. Hence the sadness-illness connection.Similarly, gains should be associated with relief and pathological relief in my opinion (via parasympathetic activation) should lead to more well-being and hence happiness- well being though gains and loss are routine, pathological/chronic gains and losses are not routine and would lead to either wellness or illness and thus the role and place for environment to influence wellness/ illness.