This is a controlled, randomized, prospective, open-label, non-inferiority trial lasting 12 months. The effectiveness of using a psychoeducational smartphone application (SIMPLe) will be compared to the effectiveness of face-to-face group psychoeducation.

Bipolar disorder (affecting 3 to 5% of French population) is characterized by the recurrence of severe symptomatic periods (depression, mania, hypomania) and interepisodic periods characterized by the persistence of residual symptoms, impaired psychosocial functioning and quality of life. The combination of psychosocial strategies with drug treatment is associated with an improvement in the prognosis of the disease. Among these complementary strategies, psychoeducation has been shown to be effective in reducing the risk of recurrence, the length of hospital stays and improving compliance. It improves an individual's understanding and knowledge of their disorder and its various treatments. Despite its effectiveness, psychoeducation for bipolar disorder remains relatively scarcely applied in France due to a limited healthcare offer (44 available programmes labeled by the Regional Health Agencies in 2017).

In recent years, a significant number of smartphone applications have been developed in the field of mental health. To date, none of these applications has proven effective in patients with bipolar disorder. In this context, the Institute of Neuroscience of Barcelona has developed a "SIMPLe" application to assess and record a subject's symptoms and deliver personalized psychoeducation. In terms of efficacy, a study has shown the interest of this application in improving biological rhythms, thereby reducing the risk of relapse and improving psychosocial functioning and the quality of life of patients suffering from bipolar disorder in remission phase. This application has been translated and adapted into French as part of a partnership with the Barcelona Institute of Neuroscience. However, the benefits of this type of application in terms of effectiveness, accessibility or reduction of health costs have never been studied in comparison to face-to-face psychoeducation programmes. This research project therefore represents a real opportunity to evaluate for the first time the effectiveness of an application allowing the delivery of personalized psychoeducation in comparison to a face-to-face group psychoeducation program (reference treatment for relapse prevention).

The SIMPLe app includes 5 daily questions (mood, energy, sleep, irritability, medication adherence) that will assess different areas associated with bipolar disorder. The user will also receive a weekly test to determine the presence and intensity of depressive or manic symptoms. Daily and personalized psychoeducation messages (adapted to the answers to the tests carried out) will be sent to the user by notifications. The app contains a bank of around 400 psychoeducational messages, based on Prof. Vieta and Dr Colom's Psychoeducation Manual for Bipolar Disorders.

Eligible patients, after obtaining their consent, will be randomized (i) either in the face-to-face psychoeducation group which will consist of the participation by the patients in all the sessions of a therapeutic education program (labeled and controlled by their Regional Health Agency) of the investigator center, (ii) or in the SIMPLe application group and will benefit from access to the application via a code that will be sent to them.

Three additional visits to the usual care are planned (assessment visit, 6 months and 12 months). At each visit, patients must complete questionnaires (CSRI, YMRS, MADRS, FAST, MARS, WHOQOL-BREF and EQ-5D).

The hypothesis formulated by the investigator is that a psychoeducational strategy using the SIMPLe smartphone application has an effect comparable to participation in a face-to-face psychoeducation group, in term of the recurrence prevention in a sample of stabilized patients with bipolar disorder (at 12 months). The recurrence rate is defined by the percentage of patients having presented a mood episode of bipolar disorder, namely a major depressive episode, manic or hypomanic episode, according to the criteria of DSM-5 and on the basis of the judgment of the clinician since the beginning of the intervention.

Inclusion Criteria:

• Suffering from bipolar disorder (type 1 or 2) according to DSM-5 criteria
• Not presenting a mood episode according to DSM-5 criteria
• Stable for at least 1 month with scores on YMRS < 8 and MADRS < 8
• Owning a smartphone
• Agreeing to attend group psychoeducation sessions
• Having no problem understanding fluent French
• Having given free and informed consent and signed the consent to participate in the study
• Available for 12 onth follow-up

Exclusion Criteria:

• Not having a smartphone compatible with the SIMPLe application
• Cannot attend psychoeducation group sessions on a regular basis
• Not having given their consent to participate in the study or unable to give their informed consent
• Not affiliation with a social security scheme
• Having a legal protection measure (safeguard of justice or guardianship)

Eligible patients after obtaining their consent will be randomized:

• either in the face-to-face psychoeducation group and will benefit from a programme of psychoeducation sessions available at the participating center.
• or in the SIMPLe application group and will have access to the application (personal access).