What is the difference between ‘Mood’ and ‘Affect’ in Psychology?

In everyday conversations, we often use words like feeling, emotion, mood, and affect interchangeably. But in psychology and clinical practice, each has a specific meaning and understanding those nuances can completely change how we make sense of our inner world.

Mental Status Examination forms a very important part in the diagnosis of any condition in psychiatry.

Amongst others, mood and affect form a a very important part which helps in establishing the diagnosis.

Let’s break it down.

Feelings, Emotions, and Their Interplay

A feeling is your personal, subjective reaction to an experience which can be pleasant or unpleasant. It’s how you consciously interpret an emotional state. You might say you “feel anxious,” “feel low,” or “feel excited.”

These feelings arise from emotions, which are more immediate and physiological. Emotions are the body’s stirred-up response to a situation like your heart racing in fear, a rush of warmth when happy, or tension when stressed. They help you react, adapt, or protect yourself.

But when we zoom out and look at the broader picture, two major emotional constructs stand out: mood and affect.

Mood: The Emotional Climate

Think of mood as the emotional backdrop against which your thoughts and experiences play out. It is:

• Pervasive: It colours everything, be it your interactions, perceptions, or energy levels.
• Sustained: It lasts for hours, days, or even longer, rather than appearing moment-to-moment.
• Subjective: The person can usually describe it like “I’ve been feeling low,” “I’m irritable,” “I feel uplifted.”

A proper description of mood considers:

• Intensity: Mild, moderate, severe
• Duration: How long it has lasted
• Fluctuations: Is it stable or does it vary?

Mood is like the climate, stable over a period of time.

Affect: The Emotional Weather

In contrast, affect is the immediate emotional expression a clinician observes in the moment. It is short-lived, dynamic and shifting as the conversation unfolds. Affect is inferred from facial expressions, tone of voice, posture, and other nonverbal cues.

Affect may be:

• Full / within normal range
• Constricted (slightly reduced)
• Blunted (significantly reduced)
• Flat (almost no visible emotional expression)

Importantly, affect can be:

• Congruent with mood (a person who feels sad looks sad), or
• Incongruent (a mismatch between internal mood and outward expression)

Affect is like the weather that is changing moment by moment.

Why the Distinction Matters

Although mood and affect are connected, they don’t always align. Someone might say they are feeling better (mood improving) but still appear withdrawn (affect restricted). Or they may present with bright affect but internally feel distressed.

Clinically, understanding the difference helps in diagnosing mental health conditions, assessing emotional wellbeing, and tracking therapeutic progress.

In Essence

• Mood = sustained internal emotional state
• Affect = momentary outward emotional expression

Recognising this difference not only enriches psychological assessment but also deepens our personal understanding of how we feel versus how we show it.