evolutionary psych- depression 1

energy conservation hypothesis

•Depressive symptoms such as fatigue and low motivation may conserve energy.

•In ancestral environments, conserving energy during scarcity increased survival chances.

•Reduced activity levels could have helped prevent unnecessary risks or conflicts.

•This hypothesis explains why physical inactivity is a core feature of depression.

social withdrawal

Social withdrawal is common in depression and may have evolved as a protective response.

Avoiding conflict or social rejection could have helped conserve social bonds in small groups.

In ancestral times, social rejection could have led to isolation and death.

Modern loneliness can trigger the same mechanisms, worsening depressive symptoms.

ruminiation

repetitive neg thinking about problems and failures

• excessive prolongs depressive episodes and increases distress

• cog therapies aim to reduce maladaptive rumination patterns

why rumination evolve?

cognitive strategy to solve complex social problems

some theories think depression promotes?

deep analytical thinking

• in the past rumination may have solved complex problems

depression and immune system activation

Inflammation is closely linked to depressive symptoms.

Infections and chronic stress trigger immune responses that affect mood.

Pro-inflammatory cytokines can induce behaviours resembling depression.

This supports the theory that depression may be a sickness behaviour response

why early childhood stress increases vulnerability to depression

Trauma and neglect affect brain development and stress regulation.

Evolutionary theories suggest early adversity calibrates emotional responses for survival.

Understanding early trauma can improve preventive interventions.

postpartum depression

•Trauma and neglect affect brain development and stress regulation.

•Evolutionary theories suggest early adversity calibrates emotional responses for survival.

•Understanding early trauma can improve preventive interventions.

depression and social rank theory

• Low social status is associated with higher rates of depression.

• Depression may signal submissiveness, reducing the likelihood of conflict.

• Social hierarchy plays a role in stress-related mental health disorders.

• Improving perceived social status can alleviate depressive symptoms.

depression and loneliness

• Loneliness is a significant trigger for depression.

• Humans evolved as highly social creatures, making isolation distressing.

• Chronic loneliness activates stress responses, increasing inflammation.

• Social interventions can help mitigate depressive symptoms.

depression and seasonal affective disorder

Seasonal changes affect mood regulation in vulnerable individuals.

Reduced sunlight exposure lowers serotonin levels, contributing to depression.

Light therapy is an effective treatment for Seasonal Affective Disorder (SAD).

Evolutionary theories suggest SAD may have once conserved energy during winter.

depression and mismatch theory

Modern environments differ from ancestral conditions, influencing mental health.

High stress, sedentary lifestyles, and social isolation increase depression risk.

The brain evolved for short-term threats, not chronic stressors.

genetic basis of depression

Depression has a heritable component influenced by multiple genes.

Evolutionary pressures may have selected for traits that predispose to depression.

Some genetic variants linked to depression may have had past survival benefits.

Identifying genetic markers can improve personalized treatments.

Depression and stress response

Chronic stress is a major trigger for depression.

The hypothalamic-pituitary-adrenal (HPA) axis regulates the stress response.

Dysfunction in the HPA axis is common in depression.

Stress-reduction strategies can improve depressive symptoms.

Depression and anxiety

often cooccur together

• Both conditions involve heightened stress responses and negative thought patterns.

• Evolutionarily, anxiety may have prevented risks, while depression signalled distress.

• Understanding their overlap can improve treatment approaches.

Evolutionary Purpose of Sadness

• Sadness is a universal emotional response across cultures.

• It may have evolved to signal distress and elicit social support.

• Short-term sadness can enhance problem-solving and learning from mistakes.

  • Chronic sadness, however, becomes maladaptive and leads to depression.

Depression and Sleep Disruptions

• Depression is strongly linked to sleep disturbances.

• Insomnia and hypersomnia are common in major depressive disorder.

• Sleep problems may exacerbate depressive symptoms by affecting neurotransmitters.

• Improving sleep quality is crucial for depression treatment.

Depression and suicide risk

• Suicidal thoughts are a severe consequence of depression.

• From an evolutionary perspective, suicide remains a paradox.

• Some theories suggest it may have historically signalled distress to elicit help.

• Suicide prevention efforts must consider both biological and social factors.