SPOILER ALERT! ~ Tracking a person’s mood can be an indicator of potential pathologies: ~ Depression: the individual maintains a negative mood for long periods of time. It doesn’t change ~ Anxiety: the individual has unstable moods that change too much and too fast between positive and negative.
Although negative affect is a common feature of both anxiety and depression, they are diagnostically distinct. Specifically, anxiety concerns worry and apprehension about the future, while depression is a focus on past mistakes and failures. As a result, heightened physiological arousal is uniquely associated with anxiety, and by contrast depression is specifically linked with low positive affect
Affective features of Anxiety and depression
Furthermore recent research suggests that individual differences in anxiety and depression are associated with the temporal dynamics of positive and negative emotions. This means that the time pattern of those moods is what distinguishes the two conditions.
For example, evidence shows that individuals entering a depressive episode typically experience a negative mood that remains constant over a period of time. By contrast, heightened instability of affect (i.e., a mood that changes constantly) is associated with anxiety.
Identifying the differences in a person’s mood involves looking at three fundamental aspects. These are the individual’s mood at baseline, the changes from that baseline, and finally the processes that bring the individual’s mood back to its baseline.
Thus, it has been suggested to examine affect dynamics in real time among a non-clinical population (i.e., people without a mental health condition) by tracking their moods throughout the day. More particularly, over a period of 10 days, participants receive SMS messages during the day prompting them to rate their current positive mood and negative mood.
Differences in affect dynamics predict risk for anxiety and/or depression
The data accumulated from those records indicate that instability of mood, average mood and ability to regulate mood are all associated with increased risk for mood disorders.
More importantly, what represents a risk factor for developing depression is the average level of positive and negative affect (i.e., more time in negative mood and little time in positive mood), while in anxiety it is the instability of positive and negative affect (positive and negative moods fluctuate too frequently).
More specifically, individuals who reported longer negative affect experienced severe depressive episodes (not at a clinical level). By contrast, those who reported more frequent mood switch experienced more severe anxiety.
Thus, these findings highlight the role of emotion dysregulation in predicting risk for mood and anxiety disorders. It also begs the question of whether the affective instability observed in anxiety simply disappears when transitioning into a depressed state, since anxiety often precedes depression.
Heller AS, Fox AS, Davidson RJ. Parsing affective dynamics to identify risk for mood and anxiety disorders. Emotion. 2019 Mar;19(2):283-291. doi: 10.1037/emo0000440. Epub 2018 Jun 4. PMID: 29863379; PMCID: PMC6279626