Sonja Lyuborminsky drew my attention to this in The How of Happiness. Here is the link to the inventory.
Can happiness be measured? The Oxford Happiness Questionnaire attempts to do just that. Developed by Michael Argyle and Peter Hills of Oxford Brookes University, and originally published in 2002 in the Journal of Personality and Individual Differences, it’s one several measures of “subjective wellbeing” (aka happiness) constructed by scientific research psychologists.
You might try the assessment several times over some extended period: take the questionnaire now, and return at a later date to take it again, comparing scores (perhaps after trying some exercises to increase happiness). There are just 29 questions, so it won’t take long.
Another brief entry from Lyubomirsky’s happiness series. The title may seem all too obvious to anyone struggling with depression. But don’t confuse “takes work” with “just snap out of it” or similar well meaning, but useless, encouragement. Lyubomirsky’s work asserts that these are habits that we develop to maintain and bolster our happiness. We don’t just diet for two weeks. We don’t go to psychotherapy for a month. We patiently and diligently apply ourselves to these tasks, knowing that over time they yield significant benefits.
Some of the approaches are not indicated for those struggling with depression. (Expressing gratitude can be especially challenging and lead to a spiral of self-criticism for lack of gratitude, for instance.) But the notion, according to her research, that 40 percent of one’s happiness is mediated by one’s own actions is a powerful idea — and contradicts the sea of hopelessness that depression pulls for.
It should be obvious that these practices are not a cure for depression. Depression and happiness are not on the same scale. (One writer compared sadness to the common cold, depression to cancer.) But increasing our general level of happiness, can help inoculate us from some of the triggers that lead to depressive episodes.
[edit: I updated the link, which was incorrect.]