Psych · General adult psychiatry — bipolar and related disorders
Bipolar II disorder and cyclothymia
Also known as Bipolar II · BP-II · Hypomania · Cyclothymic disorder · Cyclothymia · Soft bipolar · Bipolar spectrum depression
Exam-exhaustive fellowship reference on bipolar II disorder and cyclothymia — hypomania versus mania thresholds, misdiagnosis as recurrent unipolar depression, antidepressant switch and cycle-acceleration risk, lamotrigine titration and depression-prevention role, quetiapine evidence in bipolar II depression (BOLDER/EMBOLDEN), STEP-BD antidepressant findings, cyclothymic disorder criteria, and RANZCP/NICE/CANMAT/BAP deltas. FRANZCP-primary, globally tagged.
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Target exams
Red flags
- Recurrent 'treatment-resistant depression' without a structured lifetime hypomania screen and collateral — classic bipolar II miss
- Antidepressant monotherapy in known or highly suspected bipolar II — switch, mixed features, and cycle-acceleration risk
- Any psychotic features, hospitalisation for elevated mood, or ≥7-day marked impairment — reclassify as mania / bipolar I, not hypomania
- Lamotrigine rash with systemic features, mucosal involvement, or blistering — stop drug and escalate as possible SJS-TEN
- Bipolar II depression with active suicidal intent or plan — same-day senior review; do not minimise risk because 'it is only bipolar II'
- Restarting full-dose lamotrigine after interruption of more than about 5 days — restart low and retitrate
Meet the patient
A 35-year-old teacher arrives with "treatment-resistant depression" and her fourth antidepressant trial. She is flat, hypersomnic, and losing hope. Her husband, asked to stay for five minutes, mentions her amazing weeks — every spring, about four days of three hours' sleep, the house redecorated, a credit card quietly maxed. She calls them "the good weeks" and never thought to report them. Why would she? They feel like recovery.[12][14]
Every examiner's trap in this topic is in that room: the diagnosis was never in her depression — it was in her husband's collateral.[1][12]
References18ShowHide
- [1]Merikangas KR, Jin R, He JP, et al. Prevalence and correlates of bipolar spectrum disorder in the world mental health survey initiative Arch Gen Psychiatry, 2011.PMID 21383262
- [2]Calabrese JR, Keck PE Jr, Macfadden W, et al. A randomized, double-blind, placebo-controlled trial of quetiapine in the treatment of bipolar I or II depression Am J Psychiatry, 2005.PMID 15994719
- [3]Thase ME, Macfadden W, Weisler RH, et al. Efficacy of quetiapine monotherapy in bipolar I and II depression: a double-blind, placebo-controlled study (the BOLDER II study) J Clin Psychopharmacol, 2006.PMID 17110817
- [4]Sachs GS, Nierenberg AA, Calabrese JR, et al. Effectiveness of adjunctive antidepressant treatment for bipolar depression N Engl J Med, 2007.PMID 17392295
- [5]Goodwin GM, Bowden CL, Calabrese JR, et al. A pooled analysis of 2 placebo-controlled 18-month trials of lamotrigine and lithium maintenance in bipolar I disorder J Clin Psychiatry, 2004.PMID 15096085
- [6]Calabrese JR, Bowden CL, Sachs G, et al. A placebo-controlled 18-month trial of lamotrigine and lithium maintenance treatment in recently depressed patients with bipolar I disorder J Clin Psychiatry, 2003.PMID 14628976
- [7]Calabrese JR, Bowden CL, Sachs GS, et al. A double-blind placebo-controlled study of lamotrigine monotherapy in outpatients with bipolar I depression J Clin Psychiatry, 1999.PMID 10084633
- [8]Calabrese JR, Suppes T, Bowden CL, et al. A double-blind, placebo-controlled, prophylaxis study of lamotrigine in rapid-cycling bipolar disorder J Clin Psychiatry, 2000.PMID 11105737
- [9]Calabrese JR, Huffman RF, White RL, et al. Lamotrigine in the acute treatment of bipolar depression: results of five double-blind, placebo-controlled clinical trials Bipolar Disord, 2008.PMID 18271912
- [10]Young AH, Calabrese JR, Gustafsson U, et al. Quetiapine monotherapy in bipolar II depression: combined data from four large, randomized studies. Int J Bipolar Disord, 2013.PMID 25505677
- [11]Yatham LN, Kennedy SH, Parikh SV, et al. Canadian Network for Mood and Anxiety Treatments (CANMAT) and International Society for Bipolar Disorders (ISBD) 2018 guidelines for the management of patients with bipolar disorder Bipolar Disord, 2018.PMID 29536616
- [12]Malhi GS, Bell E, Bassett D, et al. The 2020 Royal Australian and New Zealand College of Psychiatrists clinical practice guidelines for mood disorders Aust N Z J Psychiatry, 2021.PMID 33353391
- [13]Goodwin GM, Haddad PM, Ferrier IN, et al. Evidence-based guidelines for treating bipolar disorder: Revised third edition recommendations from the British Association for Psychopharmacology J Psychopharmacol, 2016.PMID 26979387
- [14]Grande I, Berk M, Birmaher B, et al. Bipolar disorder Lancet, 2016.PMID 26388529
- [15]Cipriani A, Hawton K, Stockton S, et al. Lithium in the prevention of suicide in mood disorders: updated systematic review and meta-analysis BMJ, 2013.PMID 23814104
- [16]Perlis RH, Ostacher MJ, Goldberg JF, et al. Transition to mania during treatment of bipolar depression Neuropsychopharmacology, 2010.PMID 20827274
- [17]McKnight RF, Adida M, Budge K, et al. Lithium toxicity profile: a systematic review and meta-analysis Lancet, 2012.PMID 22265699
- [18]Young AH, McElroy SL, Bauer M, et al. A double-blind, placebo-controlled study of quetiapine and lithium monotherapy in adults in the acute phase of bipolar depression (EMBOLDEN I) J Clin Psychiatry, 2010.PMID 20122369