Affective Mood Disorders
Definition | Aetiology | Pathophysiology | Risk factors | Signs and symptoms | Investigations | Management
Definition
Affective Mood Disorders are a group of psychiatric conditions characterised by disturbances in mood, ranging from depressive states to manic or hypomanic episodes, which significantly impair daily functioning.
Aetiology
- Genetic factors: strong hereditary component, with multiple risk-associated genes.
- Neurochemical imbalances: dysregulation of serotonin, dopamine, and noradrenaline.
- Neurobiological abnormalities: altered activity in the limbic system and prefrontal cortex.
- Psychosocial factors: childhood trauma, stressful life events, and chronic stress.
Pathophysiology
- Reduced serotonin and noradrenaline transmission in depression.
- Increased dopamine activity in mania.
- Hypothalamic-pituitary-adrenal (HPA) axis dysregulation, leading to increased cortisol levels.
- Structural brain changes, including reduced hippocampal volume in depression.
Risk factors
- Family history of mood disorders.
- Chronic medical conditions (e.g., diabetes, cardiovascular disease).
- Substance misuse (e.g., alcohol, stimulants).
- Psychosocial stressors (e.g., bereavement, unemployment).
- Hormonal imbalances (e.g., postpartum period, thyroid dysfunction).
Signs and symptoms
- Depressive episodes:
- Persistent low mood, anhedonia.
- Fatigue, sleep disturbances.
- Changes in appetite, weight loss or gain.
- Feelings of worthlessness, excessive guilt.
- Suicidal ideation or self-harm.
- Manic or hypomanic episodes:
- Elevated or irritable mood.
- Increased energy, reduced need for sleep.
- Pressured speech, racing thoughts.
- Risk-taking behaviour, grandiosity.
Investigations
- Comprehensive psychiatric assessment: history and mental state examination.
- Structured diagnostic tools: Patient Health Questionnaire-9 (PHQ-9).
- Collateral history: from family or caregivers.
- Blood tests: FBC, U&Es, LFTs, TFTs, vitamin B12, folate to exclude organic causes.
- ECG: if considering medication that affects cardiac function.
Management
1. Pharmacological management:
- Depressive episodes:
- SSRIs (e.g., sertraline, fluoxetine) as first-line treatment.
- SNRIs (e.g., venlafaxine, duloxetine) if SSRIs are ineffective.
- Mirtazapine for patients with sleep disturbance.
- Manic episodes:
- Atypical antipsychotics (e.g., olanzapine, risperidone, quetiapine).
- Mood stabilisers (e.g., lithium, valproate).
- Long-term maintenance:
- Lithium as first-line for bipolar disorder.
- Lamotrigine for mood stabilisation in bipolar depression.
2. Psychological and social interventions:
- Cognitive Behavioural Therapy (CBT) for depressive symptoms.
- Interpersonal therapy (IPT) for social and relationship issues.
- Family-focused therapy for managing bipolar disorder.
3. Lifestyle modifications:
- Regular physical exercise.
- Sleep hygiene measures.
- Substance misuse avoidance.
4. Crisis and referral management:
- Crisis team referral: if acute suicidal risk.
- Community mental health team (CMHT): for long-term follow-up.
- Hospital admission: if severe mood disturbance or suicidality.