Depression is a common mental health condition that can cause feelings of sadness, hopelessness, and worry. It can also make it difficult to concentrate, remember things, or make decisions. Other symptoms include physical issues like headaches, stomachaches, or sexual dysfunction, and thoughts of self-harm or suicide. 

Therapy, or psychotherapy, can be an effective treatment for depression. It can help people learn to cope with negative thoughts and difficult experiences, and develop healthier behaviors. Therapy can also help people identify and change unhelpful thoughts and behaviors, and learn to set realistic goals. 

There are several different types of therapy, including cognitive behavioral therapy (CBT), interpersonal therapy (IPT), behavior therapy, and mindfulness-based cognitive therapy (MBCT). Each type of therapy can help with different aspects of depression, such as stress, new perspectives, and sticking to treatment. 

In addition to therapy, other treatments for depression include medication, brain stimulation therapy, and general measures like relaxation techniques.