There were two interesting twists in their findings. The first was that bad was stronger than good, as is almost always the case in psychology.55 Depression was significantly more contagious than happiness or good mental health. The second twist was that depression spread only from women. When a woman became depressed, it increased the odds of depression in her close friends (male and female) by 142%. When a man became depressed, it had no measurable effect on his friends.
