The relationship between mood instability and depression: implications for studying and treating depression

Area of Science:

• Psychiatry
• Clinical Psychology
• Mental Health Research

Background:

• Mood instability is frequently reported by individuals with depressed mood, fluctuating within hours or days.
• Current diagnostic criteria and rating scales for depression do not recognize mood instability.
• This omission may stem from reliance on retrospective recall and structured interviews in assessments.

Purpose of the Study:

• To investigate mood instability as a distinct component in the development of depression.
• To determine the relationship between mood instability and depressive symptoms.
• To advocate for the inclusion of mood instability in depression criteria to enhance research.

Main Methods:

• Examined three datasets utilizing retrospective and prospective measures of depressed symptoms and mood instability.
• Employed scales such as the Eysenck Personality Inventory Neuroticism Scale, Affective Lability Scale (ALS), and Visual Analogue Depression Scale (VAS).
• Utilized partial correlation and exploratory factor analysis to assess associations and factor structures.

Main Results:

• Mood instability showed a moderate association with depressive symptoms (Pearson's r-values from 0.49 to 0.57).
• The correlation was weaker when mood was assessed retrospectively.
• Factor analysis supported mood instability and depressive symptoms as related yet distinct constructs.

Conclusions:

• Exclusive reliance on retrospective assessment of depressive symptoms has obscured the prevalence of mood instability.
• Incorporating mood instability into diagnostic and assessment criteria is crucial for advancing causal and treatment research in depression.