Despite some claims made online to the contrary, Suboxone isn’t typically associated with personality changes, especially on a long-term basis.
Suboxone isn’t typically associated with changes to mood and personality.
Suboxone combines the drugs buprenorphine and naloxone and is typically used to help treat people who have opioid use disorder (OUD). It is a partial opioid agonist which means it helps to curb cravings for opioids.
Taking Suboxone as intended helps treat opioid withdrawal symptoms. However, suddenly stopping your medication or otherwise not taking it as prescribed may cause you to undergo withdrawal, which may cause temporary irritability and mood swings. 
No. Research doesn’t show Suboxone having a notable long-term effect on personality. In fact, because Suboxone treats OUD and OUD itself can cause worsening depression and anxiety, treatment with Suboxone alone may reduce symptoms of depression or anxiety by treating the underlying OUD. 
Reviewing what medical literature is currently available, mood swings are not commonly associated with Suboxone. While the claim Suboxone causes mood swings is often repeated, actual medical research doesn’t back this claim as far as we know.
If you do experience changes in mood, mood swings, or personality changes while on Suboxone, talk openly with your doctor. There may be multiple causes of changes in your mood other than your medication.