We will modify our existing VMQ/VADIS mood telemetry software to run on a Motorola platform, and enhance it to collect information on both mood symptoms (currently covered by the VMQ/VADIS) as well as daily life stressors (currently outside the VMQ/VADIS' scope). By doing so, we will be able us to examine the role of daily stressors in the lives of teens with and without mood swings, to identify how changes in mood triggered by stressful events are similar to or different from mood changes linked to the bipolar disorder, borderline personality disorder, or other forms of affective instability.

Inclusion Criteria:

• Age 14-20yrs,
• Either (i) self-reported healthy with no past / present history of substance use problems OR (ii) self-reported severe mood swings interfering with daily life.
• Fluent in English.

Exclusion Criteria:

• Inability to be trained successfully on the MHT software or to complete questionnaires without assistance.
• Unwillingness to sign / maintain a contract with a cell phone service provider.
• Lack of parental assent / willingness to act as guarantor for cell phone provider contract