b'indiscretion, and alcohol abuse decreased sleep without experiencing fatigueextreme agitation or aggressive behaviorhypersexuality or sexual statements on occasion, psychotic symptoms including paranoia, hallucinations or delusions, especially of a paranoid or grandiose nature What are the symptoms of depression? Depression is the other phase of bipolar disorder. Symptoms of depression may include: loss of energyprolonged sadnessdecreased activity and energyrestlessness and irritabilityinability to concentrate or make decisionsincreased feelings of worry and anxietyless interest or participation in, and less enjoyment of, activities normally enjoyedfeelings of guilt and hopelessness thoughts of suicide change in appetite or sleep (either more or less) What are the causes of bipolar disorder? The exact causes of bipolar disorder are not known. Most research points to an interaction of genetic factors, biochemical factors (imbalances in serotonin, dopamine, norepinephrine, and GABA) and life event stress (especiallyMental Health Concerns165'