- Loss appraisal
- The cognitive appraisal that something of value has been permanently lost or irrevocably damaged. Loss appraisal is the defining trigger for sadness across appraisal theories. What constitutes a loss varies by person and culture — it can be a relationship, status, physical capability, opportunity, or cherished belief. The appraisal of irreversibility distinguishes sadness from anxiety (which anticipates a potential future loss).
- Crying
- Emotional lacrimation — shedding tears in response to emotional states — is uniquely human (no other species cries emotionally). Ad Vingerhoets's research shows that crying is primarily a social signal: it is more common in private than public, and reliably elicits sympathy and support from observers. Crying is reported to have a mood-relieving effect, though laboratory studies show this depends on social context — crying alone without resolution often worsens mood.
- Rumination
- Repetitive, passive focus on one's distress and its possible causes and consequences, without moving toward active problem-solving. Susan Nolen-Hoeksema's response styles theory proposes that rumination prolongs and intensifies sad mood, and is a major vulnerability factor for depression. Distraction from negative feelings is more effective at lifting sad mood than ruminating on its causes.
- Mood-congruent memory
- The tendency to recall memories consistent with one's current emotional state more easily than inconsistent ones. Sad people selectively retrieve negative memories, reinforcing and prolonging the sad state. This mood-congruent processing is a key mechanism in depression maintenance — the depressed person's memory system provides a biased sample of past experience that confirms the depressive worldview.
- Grief and bereavement
- Grief is the normal emotional and psychological response to significant loss, particularly death of an attachment figure. George Bonanno's prospective research on bereavement found that the majority of bereaved people show resilience — not protracted grief — challenging stage models (Kübler-Ross) that assumed everyone progresses through defined stages. Prolonged grief disorder (ICD-11) is distinguished from normal grief by functional impairment persisting beyond 6 months.
- Adaptive function of sadness
- Sadness may serve several adaptive functions: social signalling (communicates need and elicits support), goal disengagement (facilitates withdrawal from unattainable goals, conserving resources), and analytical thinking (mild sad mood has been shown to improve attention to detail, reduce judgmental biases, and improve persuasion accuracy in some conditions — the "sadness and cognition" literature pioneered by Joseph Forgas).
- Sadness vs depression
- Normal sadness is proportionate to loss, focused on a specific cause, time-limited, and responds to positive events (anhedonia is not present). Clinical depression involves pervasive anhedonia, persistent negative cognitions about self, world, and future (Beck's cognitive triad), neurobiological disturbance (sleep, appetite, psychomotor changes), and functional impairment that persists independently of circumstances.