The Canadian Network for Mood and Anxiety Treatments (CANMAT) previously published treatment guidelines for bipolar disorder in 2005, along with international commentaries and subsequent updates in 2007, 2009, and 2013. The last two updates were published in collaboration with the International Society for Bipolar Disorders (ISBD). These 2018 CANMAT and ISBD Bipolar Treatment Guidelines represent the significant advances in the field since the last full edition was published in 2005, including updates to diagnosis and management as well as new research into pharmacological and psychological treatments. These advances have been translated into clear and easy to use recommendations for first, second, and third‐ line treatments, with consideration given to levels of evidence for efficacy, clinical support based on experience, and consensus ratings of safety, tolerability, and treatment‐emergent switch risk. New to these guidelines, hierarchical rankings were created for first and second‐ line treatments recommended for acute mania, acute depression, and maintenance treatment in bipolar I disorder. Created by considering the impact of each treatment across all phases of illness, this hierarchy will further assist clinicians in making evidence‐based treatment decisions. Lithium, quetiapine, divalproex, asenapine, aripiprazole, paliperidone, risperidone, and cariprazine alone or in combination are recommended as first‐line treatments for acute mania. First‐line options for bipolar I depression include quetiapine, lurasidone plus lithium or divalproex, lithium, lamotrigine, lurasidone, or adjunctive lamotrigine. While medications that have been shown to be effective for the acute phase should generally be continued for the maintenance phase in bipolar I disorder, there are some exceptions (such as with antidepressants); and available data suggest that lithium, quetiapine, divalproex, lamotrigine, asenapine, and aripiprazole monotherapy or combination treatments should be considered first‐line for those initiating or switching treatment during the maintenance phase. In addition to addressing issues in bipolar I disorder, these guidelines also provide an overview of, and recommendations for, clinical management of bipolar II disorder, as well as advice on specific populations, such as women at various stages of the reproductive cycle, children and adolescents, and older adults. There are also discussions on the impact of specific psychiatric and medical comorbidities such as substance use, anxiety, and metabolic disorders. Finally, an overview of issues related to safety and monitoring is provided. The CANMAT and ISBD groups hope that these guidelines become a valuable tool for practitioners across the globe.

We examined the influence of age at onset of illness and the delay in time to first treatment on morbidity in adulthood. 529 adult outpatients with a mean age of 42 years, who entered our research network from 1996 through 2001 and who were diagnosed with bipolar disorder according to DSM-IV criteria, were rated prospectively on a daily basis with the National Institute of Mental Health-Life Chart Method during naturalistic treatment for up to 4 years. Fifty percent of patients had illness onset in childhood (<13 years of age) or adolescence (13-18 years of age). In year 1 of follow-up, these patients, compared to those with adult onset, showed significantly (P<.05) greater severity of depression and mania, greater number of episodes, more days depressed, more days of ultradian cycling, and fewer days euthymic. After 4 years, the mean severity and duration of depression remained greater and the number of days euthymic fewer in those with childhood compared to adult onset (P<.05). The delays to first treatment correlated inversely with age at onset of illness. Independently, delay to first treatment was associated with more time depressed, greater severity of depression, greater number of episodes, more days of ultradian cycling, and fewer days euthymic (all P<.05). These data converge with other evidence that onset of bipolar disorder in childhood is common and often associated with extraordinarily long delays to first pharmacologic treatment. Both childhood onset and treatment delay were associated with a persistently more adverse course of illness rated prospectively in adults. These data should help foster efforts to ensure earlier and more effective treatment of bipolar illness in children and adolescents. It is hoped that appropriate early intervention would result in a more benign illness and a better prognosis in adulthood.