Bipolar Disorder — Types, Causes, Symptoms & Treatment Guide — Symptoms, Causes & Treatment | MyMedicPlus

Bipolar disorder is a chronic, episodic psychiatric mood disorder characterised by pathological fluctuations in mood, energy, cognition, and behaviour — oscillating between episodes of mania or hypomania (elevated, expansive, or irritable mood with increased energy and activity) and depressive episodes (low mood, anhedonia, fatigue, and cognitive slowing) separated by intervals of relative euthymia (normal mood). It is classified into several types by DSM-5 and ICD-11: Bipolar I Disorder — defined by at least one full manic episode (lasting at least 7 days or requiring hospitalisation) with or without major depressive episodes; Bipolar II Disorder — defined by at least one hypomanic episode (lasting at least 4 days, not requiring hospitalisation, causing observable change but not severe impairment) plus at least one major depressive episode, without full mania; Cyclothymic Disorder — subsyndromal hypomanic and depressive symptoms over at least 2 years; and other specified/unspecified bipolar and related disorders. Globally, bipolar disorder affects approximately 40-60 million people (1-2% of the population), with broadly equal prevalence in men and women (though men more commonly present with manic episodes and women with depressive episodes). Bipolar I has a lifetime prevalence of approximately 0.6% and Bipolar II of approximately 0.4% across cultures and countries. Bipolar disorder ranks as the 6th leading cause of disability-adjusted life years (DALYs) from neuropsychiatric conditions globally — due to high symptom burden, functional impairment during depressive phases, and the chronicity of the condition over a lifetime. Life expectancy is reduced by 10-20 years compared to the general population, primarily from cardiovascular disease (driven by metabolic effects of antipsychotics and lifestyle factors), respiratory disease, and suicide.

Bipolar disorder is one of the most heritable psychiatric disorders — monozygotic (identical) twin concordance is 60-85%, and first-degree relatives of bipolar patients have a 5-10% lifetime risk (compared to 0.5-1% in the general population); if both parents have bipolar disorder, the child's risk rises to approximately 50-75%. Genome-wide association studies (GWAS) have identified risk loci including CACNA1C (L-type calcium channel — shared with schizophrenia and major depression), NCAN, ODZ4, and genes within lithium-response pathways. Despite strong genetics, environmental factors are essential for episode precipitation. Neurobiological mechanisms: dysregulation of dopaminergic, serotonergic, and noradrenergic pathways — particularly the mesolimbic dopamine system (overactive in mania, underactive in depression) and serotonin-dopamine interactions; HPA axis hyperactivation produces elevated cortisol in acute mood episodes; structural neuroimaging shows reduced prefrontal cortex grey matter, enlarged amygdala, and reduced hippocampal volume in bipolar disorder, contributing to the cognitive impairment observed in 60-70% of patients. Mitochondrial dysfunction and oxidative stress are increasingly recognised as key pathophysiological features. Environmental and psychosocial risk factors: childhood adversity (ACEs — abuse, neglect, attachment disruption) significantly increases bipolar risk and episode severity; traumatic life events and chronic stress are major episode precipitants; sleep disruption and circadian rhythm dysregulation are both a cause and consequence of mood episodes — disrupted sleep (crossing time zones, shift work, life stress) can precipitate manic episodes within days; substance misuse — cannabis use (particularly high-THC varieties) can precipitate first manic episodes in genetically vulnerable individuals; cocaine and amphetamines directly trigger mania; alcohol worsens mood instability and treatment response. Postpartum period: the highest risk period for a first manic episode or severe relapse — particularly in Bipolar I; vigilance and prophylactic management throughout pregnancy and puerperium is essential.

Manic episode (DSM-5 criteria — at least 7 days or requiring hospitalisation; at least 3 of 7 DIGFAST criteria present — or 4 if mood is irritable rather than elevated): Distractibility (unable to focus on tasks); Irresponsibility/recklessness (excessive spending/shopping, gambling, hypersexuality, dangerous driving, reckless business decisions, substance use); Grandiosity (inflated self-esteem, unrealistic sense of special powers, abilities, or destiny — ranging from heightened confidence to frank delusions of grandeur); Flight of ideas/racing thoughts (thoughts racing faster than speech; rapid associative thinking; topic-jumping); Activity increase (increased goal-directed activity — new projects, plans, ambitious schemes — or psychomotor agitation); Sleep decreased need (typically 3-4 hours feeling fully rested; a prodromal 'warning sign' of mania onset); Talkativeness/pressured speech (rapid, loud, difficult to interrupt). Manic episodes may include psychotic features (delusions — grandiose or persecutory; hallucinations — auditory) in 50-75% of severe manic episodes. Hypomanic episode (Bipolar II): same DIGFAST symptoms as mania but lasting only 4 days minimum, not causing severe impairment or requiring hospitalisation, and without psychotic features. Depressive episode in bipolar disorder: persistent low mood and/or anhedonia (loss of interest in previously pleasurable activities) for at least 2 weeks; associated symptoms include fatigue and loss of energy (often profound — 'lead-like' heaviness in limbs), worthlessness and inappropriate excessive guilt, concentration difficulties and cognitive slowing, hypersomnia (sleeping 10-16 hours — characteristic of bipolar depression, distinguishing it from unipolar depression which more often has insomnia), psychomotor retardation, appetite changes (often increased with weight gain in bipolar depression), and suicidal ideation or attempts. Bipolar depressive episodes cause the majority of lifetime disability burden in bipolar disorder. Mixed features (DSM-5): concurrent manic and depressive features — characterised by severe dysphoric energy, suicidal ideation, irritability, and racing dark thoughts; the highest-risk state for suicide and self-harm in bipolar disorder. Rapid cycling (4 or more mood episodes in 12 months) affects 15-20% of bipolar patients and is associated with worse prognosis, more frequent antidepressant use, and thyroid dysfunction.

Diagnosis is clinical — based on DSM-5 or ICD-11 criteria applied through a comprehensive psychiatric evaluation including structured or semi-structured clinical interview (e.g., SCID — Structured Clinical Interview for DSM Disorders), thorough personal and family psychiatric history, and longitudinal course assessment. Validated screening tools: the Mood Disorder Questionnaire (MDQ — 13-item self-report screen for lifetime manic/hypomanic symptoms; sensitivity 73%, specificity 90% for Bipolar I); the Hypomania Checklist (HCL-32); and the Young Mania Rating Scale (YMRS) for severity quantification of current manic episodes; the Montgomery-Åsberg Depression Rating Scale (MADRS) for depressive severity monitoring. The average diagnostic delay in bipolar disorder is 6-10 years from symptom onset — the most critical reason being that patients most commonly present for help during depressive episodes and are misdiagnosed with unipolar major depression (50-70% of eventual bipolar diagnoses were initially diagnosed as unipolar depression). Key differential diagnoses requiring systematic exclusion: major depressive disorder (no history of mania/hypomania — eliciting prior hypomanic episodes requires direct questioning about past periods of elevated energy, reduced sleep, and increased activity); ADHD (distractibility and impulsivity overlap with mania — onset age, chronic vs. episodic pattern, and family history differentiate); borderline personality disorder (rapid mood shifts are reactional and interpersonally triggered, not episodic — self-harm and abandonment fears predominate); schizophrenia and schizoaffective disorder (psychotic symptoms persist outside mood episodes); cyclothymia; and secondary mania from organic causes. Medical investigations to exclude secondary causes and establish baseline for medication management: thyroid function tests (TSH — hyperthyroidism mimics mania; also baseline for lithium monitoring); full metabolic panel and LFTs (baseline before mood stabilisers); eGFR and 24-hour urine creatinine clearance (baseline before lithium — nephrotoxic); prolactin, FBC, coagulation (before antipsychotics and valproate); urine toxicology screen (stimulants, cannabis); ECG (baseline QTc before antipsychotics); brain MRI when new-onset mania presents atypically (neurological symptoms, older age, no family history — to exclude brain tumour, stroke, or encephalitis).

Bipolar disorder management requires a combination of medication, psychotherapy, and structured lifestyle measures — most patients require lifelong treatment. Acute mania treatment: first-line — antipsychotics: haloperidol, olanzapine, risperidone, aripiprazole, or quetiapine — provide rapid symptom control; benzodiazepines (lorazepam, clonazepam) as adjuncts for acute agitation and sleep; lithium or valproate add-on for sustained antimanic effect. Lithium (the gold standard mood stabiliser): therapeutic plasma level 0.6-1.0 mmol/L (manic phase: 0.8-1.0 mmol/L; maintenance: 0.6-0.8 mmol/L); proven to reduce mania, depression, and suicide risk by 80-90% (the only psychotropic with level 1 evidence for suicide reduction); requires monitoring of plasma lithium levels (weekly initially, then 3-6 monthly), eGFR and TFTs every 6 months (nephrotoxic in the long term — affects 20-30% of long-term users; causes hypothyroidism in 20-40%); narrow therapeutic index — toxicity risk with dehydration, NSAIDs, ACE inhibitors, and sodium restriction; teratogenic (Ebstein's anomaly risk — requires counselling and folic acid in women of childbearing age). Valproate (sodium valproate/valproic acid): effective for mania and mixed states — targeting 50-100 mg/L plasma levels; monitor LFTs and FBC; highly teratogenic (1,000x increased risk of neural tube defects and neurodevelopmental harm) — MHRA restricted prescribing in women without highly effective contraception and a pregnancy prevention programme. Lamotrigine: most evidence for bipolar depression prevention — target dose 200 mg/day; slow titration required to reduce risk of serious rash (Stevens-Johnson syndrome — 0.3%); less effective for acute mania. Atypical antipsychotics — quetiapine (50-300 mg/day; both mania and depression evidence), olanzapine, aripiprazole, and lurasidone (FDA-approved for bipolar depression) — used as monotherapy or adjuncts to lithium/valproate. Bipolar depression treatment: first-line — quetiapine monotherapy, lithium, or lamotrigine; lurasidone (adjunctive or monotherapy); avoid antidepressant monotherapy (risk of triggering mania, mixed states, or rapid cycling — use only with concurrent mood stabiliser and with caution). Psychotherapy: Cognitive Behavioural Therapy for Bipolar Disorder (CBT-BD) — psychoeducation, relapse prevention planning, sleep regulation, early warning sign identification; Interpersonal and Social Rhythm Therapy (IPSRT) — regulates circadian rhythms through structured daily routines; Family Focused Therapy (FFT) — reduces expressed emotion and family conflict, a major relapse trigger.

Untreated bipolar disorder causes progressive neurobiological deterioration — each episode of mania or depression causes measurable grey matter volume loss, particularly in the prefrontal cortex and hippocampus, and 60-70% of patients develop lasting cognitive impairment affecting memory, attention, processing speed, and executive function even between episodes. The kindling effect results in progressively shorter inter-episode intervals with increasing episode frequency and severity over time without effective long-term prophylaxis. Treatment-resistant illness (refractory to 2 or more adequate medication trials) occurs in 20-30% of cases, particularly in those with rapid cycling or mixed features, requiring specialist psychopharmacology review and clozapine consideration. Social and occupational consequences are severe — relationship breakdown (divorce rates 2-3 times higher than general population), job loss, financial devastation from mania-related spending and poor decisions, housing instability, and social isolation. Substance misuse co-occurs in 50-60% of bipolar patients — alcohol and cannabis use are most common and significantly worsen mood instability, treatment adherence, and long-term prognosis. Bipolar disorder carries a 15-25 fold higher suicide risk compared with the general population — approximately 25-50% of patients attempt suicide at some point; mixed episodes, hopeless bipolar depression, substance comorbidity, and early-course illness carry the highest acute suicide risk; lithium is the only mood stabiliser with proven antisuicidal effects. Life expectancy is reduced by 10-20 years from cardiovascular disease (metabolic syndrome from antipsychotics, obesity, smoking, sedentary lifestyle), substance use disorders, and suicide.

Regular sleep schedule is critically important — disrupted circadian rhythms are a primary trigger for mood episodes. Go to bed and wake at the same time every day, including weekends. Avoid alcohol and recreational drugs completely — cannabis, stimulants, and depressants all destabilise mood significantly. Reduce stress through mindfulness, yoga, or moderate regular exercise. Recognise early warning signs of mood episodes (reduced sleep need, increased energy, low mood) and act on them promptly with your treatment team. Keep a daily mood chart. Build a strong social support network. Never stop medication without medical supervision — abrupt discontinuation of lithium carries high relapse risk.

See a GP or mental health professional urgently for: a first episode of elevated mood with reduced need for sleep, grandiosity, or racing thoughts (may be a first manic episode); significant new onset depression with hopelessness or suicidal thoughts; or rapid mood swings between elation and despair. Seek immediate emergency care (999 or A&E) for: acute mania with unsafe behaviour (reckless driving, spending, dangerous activities) or psychosis (delusions, hallucinations); active suicidal intent or a serious suicide attempt; or severe self-neglect from extreme depression. If you or a family member is already diagnosed with bipolar disorder: contact your care coordinator, psychiatry team, or crisis line at the first sign of a mood episode — early intervention prevents escalation. Never discontinue mood stabilisers (lithium, valproate, lamotrigine) without psychiatric supervision — abrupt stopping carries a very high relapse risk.