Common signs of diagnosing a person who has suicidal thoughts. Becomes withdrawn. The person avoids close friends and family, loses interest in activities and social events, and becomes isolated. Shows despair. The person may talk openly about unbearable pain or feeling like they’re a burden on others. Shows swings in mood or sleep. Often, the person may be depressed, anxious, sad, or angry. They may also be very irritable, moody, or aggressive. But they can suddenly calm down once they’ve decided to go through with the suicide. Then they may sleep a lot more or a lot less than usual. Drinks or takes drugs. Rise in intake raises the chance of suicide. Besides, the following conditions may be responsible for a feeling of hopelessness, isolation and lack of meaning in life - Depression, Schizophrenia, Bipolar disorder, Some personality traits, such as aggression, Conditions that affect relationships, Traumatic brain injury, Conditions that involve chronic pain, Alcohol or drug dependence, Borderline personality disorder (BPD), Post-traumatic stress disorder.