According to the study by Dr Keelin Howard from Buckinghamshire New University, UK, Facebook users found their paranoid, manic and depressive symptoms could worsen as well as improve.
Howard carried out research with 20 people aged 23-68 who had experienced conditions such as schizophrenia, bipolar disorder, depression and anxiety.
Some participants were positive about Facebook, saying it helped them recover by making them feel less alone, allowing them to express themselves and be part of an online community.
"Many participants spoke of the way Facebook could enhance their mood through keeping up with their friends, and through receiving positive self-affirmation when other people liked or left comments on their posts," said Howard.
Facebook provided some with a less threatening means to communicate, gain and give peer support when 'face-to-face' communication was too intense.
However, some participants also said it had worsened their condition, said Howard, who presented her findings at the British Sociological Association's annual conference in Glasgow.
"Some became distressed that others' posts were aimed at them, whilst others became paranoid about how others would react to their posts. All participants with diagnoses of schizophrenia felt that Facebook was harmful when they were unwell," she added.
"Participants who identified as having bipolar disorder found that while manic they were far more active on Facebook and had posted things that they later regretted. They felt embarrassed by their comments and felt that it led to people misunderstanding them," Howard said.
"Participants found that Facebook could be a vehicle both for challenging the stigma around mental health as well as a place where prevalent stigma around mental health conditions could make survivors feel more vulnerable or reticent," Howard said.
