Carl Rogers who is the founder of Person-Centered (sometimes called Client-Centered) therapy took a humanistic approach. Humanism stresses the importance of freedom, autonomy, and the potential to grow healthily. Rogers believed only three ingredients were needed for these goals of self-actualization to be achieved. Namely, they are unconditional positive regard, genuineness, and empathy.

“Dialectical behavior therapy” is the most widely researched treatment for borderline personality disorder. It was developed by Marsha Linehan and includes 4 core components: mindfulness, distress tolerance, emotional regulation, and interpersonal effectiveness. On the other hand, “logotherapy” is an existential therapy developed by Viktor Frankl and focuses on finding meaning in life. “Cognitive behavioral therapy” is an effective treatment for depression and anxiety, and looks at the impact of one's thoughts on emotions and behaviors. “Rational emotive behavior therapy” was developed by Albert Ellis and focuses on modifying irrational thoughts. “Feminist therapy” emphasizes the impact of women's social roles and includes an equal relationship between therapist and client, therapist self-disclosure, and advocating for socio-political change. 

CBT is a form of therapy that combines Aaron Beck's cognitive therapy and techniques taken from traditional behavioral approaches, like classical and operant conditioning. On the other hand, “rational emotive behavior therapy” (REBT) was developed by Albert Ellis and focuses on changing cognitions and behaviors by focusing on irrational thoughts. “Dialectical behavior therapy” (DBT) is a behavioral approach that was developed by Linehan to treat borderline personality disorder. “Relapse prevention” is an approach to addiction developed by Marlatt that views addiction as an overlearned habit. “Stress inoculation training” is an effective behavioral treatment for PTSD that focuses on cognitions, coping skills, and practice. Of all the treatments listed, “psychoanalysis” is the most unrelated. It focuses on the interactions between the id, ego, and superego, with the goal being to increase insight into the unconscious. 

The goal of cognitive behavior therapy is to modify maladaptive cognitions (thoughts). The goal of traditional psychoanalysis is to "increase insight" into the unconscious. Psychoanalysis may also work to reduce resistance to treatment, and sees resistance as an inevitable part of the process. Psychoanalysis attempts to decrease, rather than increase, the use of defense mechanisms like repression. Psychoanalysis does not directly modify behavior. Crisis intervention focuses on resolving a crisis and restoring previous functioning. 

Lithium helps treat manic episodes, which the question mentioned Tom is struggling with. It is the most common medication for mania. Antabuse is medication for alcoholism, Focalin treats ADHD, Seroquel addresses psychosis, and Lexapro deals with anxiety.

DBT was created initially to treat BPD. This theory works best when the therapist works as part of a team so he/she can get his/her own therapy as time goes on. DBT focuses on ares where someone with BPD would struggle- building an emotional skin, regulating emotional responses, and learning good interpersonal relationship strategies.

All of these therapies can be used to treat depression and many have research to support the effectiveness of the use; however, only one of these therapies was created intentionally to treat depression. Beck's cognitive therapy was created specifically to work with depression.

Rogers believed therapists needed to be congruent, empathic, and should show unconditional positive regard towards clients in order for therapeutic change to occur. Rogers did not believe in confrontation. He thought this was too abrasive and would negatively impact the relationship with the client, which could drastically decrease the effectiveness of therapy.

Psychoanalytic therapists must worry about all of these. Transference is when a client transfers feelings they have for someone to the therapist (e.g. treating the therapist like they would their parent). Countertransference is when a therapist experiences feelings in reaction to the client, or when they over relate to something a client is saying. Defense mechanisms are unconscious ways of reacting to trauma or stress.

Adlerian therapy thinks that birth order greatly affects a person's personality and presenting problems. Psychoanalytic therapy focuses on the unconscious and the childhood. Gestalt therapy centers on body language. Person-centered therapy focuses on the relationship between the client and the counselor.